It is difficult to imagine a modern house without a sewerage system. It is a necessary element of communications that ensures comfortable living.

There are 2 types of sewerage:

**pressure**(a pump is installed inside the drain pipes, which accelerates the removal of waste into the cesspool. In this case, the slope of the pipes does not matter);**gravity**(drain occurs under the influence of gravity. To ensure normal waste removal, it is necessary to install pipes at a certain slope).

Pressure sewerage has its advantages, but requires considerable costs and regular maintenance. Therefore, gravity sewer systems are more popular. However, there are some nuances here too. In particular, it is necessary to clearly know at what angle to lay the pipes and with what diameter.

This is what we will try to find out.

## Calculator for calculating sewer slope for a private house

It is difficult to imagine a modern house without a sewerage system.

It is a necessary element of communications that ensures comfortable living. There are 2 types of sewerage:

**pressure**(a pump is installed inside the drain pipes, which accelerates the removal of waste into the cesspool. In this case, the slope of the pipes does not matter);**gravity**(drain occurs under the influence of gravity. To ensure normal waste removal, it is necessary to install pipes at a certain slope).

Pressure sewerage has its advantages, but requires considerable costs and regular maintenance. Therefore, gravity sewer systems are more popular. However, there are some nuances here too. In particular, it is necessary to clearly know at what angle to lay the pipes and with what diameter.

This is what we will try to find out.

## Slope of the external and internal parts of the system

During the installation of a sewer system, pipes are laid either straight (parallel to the floor) or at a certain angle. The first option is clearly wrong, as it blocks the movement of wastewater and, ultimately, makes the entire system inoperable.

Judging by the photo, the pipes are not even laid parallel to the floor, but with a slight inclination towards the bathtub - that is, incorrectly. When you turn on the water in the sink, it will flow not towards the riser, but straight into the bathtub

The second solution is correct, but it can be executed in different ways:

- Ensure that the angle is as sharp as possible.
- Keep the tilt to a minimum.
- Carry out installation based on the figures recommended by regulatory documents.

What will happen in each of these cases?

Option 1. It would seem that the angle is too sharp, therefore, the steep descent of the drains is not dangerous. This opinion is erroneous, since the rapid flow of liquid does not fully flush out solid waste.

As a result, they accumulate and form clogs. The second problem is associated with the failure of water seals, which results in a specific sewage smell throughout the entire house or apartment.

Another undesirable consequence that disrupts comfort is the loud noise created by wastewater falling down at high speed.

Option 2. The minimum slope is not much different from horizontal installation. The slow movement of liquid leads to silting, the formation of a thick layer of dirt on the walls of the pipes, and then regular blockages. By the way, SNiP recommends keeping the wastewater speed within the range of 0.7-1.0 m/sec.

Option 3. The most optimal solution is to provide the slope specified in the regulatory documentation, which indicates the dependence of the laying angle of the pipeline on the diameter or length of the pipe. Let's move directly to the norms and calculations.

**In a private country house, it is necessary to install not only internal, but also external sewerage. In addition, outlets are needed for water that is formed as a result of melting snow and precipitation in the form of rain. Storm drainage can be installed together with the main system or separately. **

The slope of the internal sewer pipe is strikingly different from that of the external system. For storm drainage, large-diameter pipes (from 100 mm) and gratings are required, since various pollutants of plant origin will certainly enter this system. The slope of the sewer system for storm water should also be greater - 0.05-0.07, but not more than 0.15.

External waste from the house is usually directed to a central sewer or septic tank and is laid underground. The diameter of this pipeline is most often 100-150 mm. The minimum slope is 0.02. Based on this, you should dig a trench. If inaccuracies are made during excavation work, you can correct the situation with the help of a sand cushion.

Any sewer system must provide unimpeded flow of waste and guarantee a high level of self-purification. You should definitely take into account that the standards and textbooks indicate average indicators, so common sense and practicality will never hurt.

## Why do we need a slope angle for sewer pipes?

What if the angle is too small or too sharp? Both options will be incorrect. The fact is that the speed of removal of sewage depends on the angle of slope: slow removal will lead to the fact that the water from the sink and washbasin will leave more slowly. As a result, an unpleasant odor, large particles and grease will settle inside the pipes. You will have to clean the drain more often.

The same problem occurs when the sewer is installed at an acute angle. Firstly, large particles that can damage the system and lead to its premature failure. Secondly, debris will get clogged at joints and turns, accumulations will form and, as a result, water will not pass through.

## It's all about the slope!

Beginners in construction may mistakenly believe that a larger angle of inclination of the pipe will result in faster draining.

This is wrong. Draining the water too quickly does not take any solid particles of feces with it. Over time, they will fill the pipes, remaining on the inner walls of the pipe. And the saddest thing is that this can lead to the rapid appearance of an unpleasant odor. This will happen if the water seals in the siphons fail. In addition, rapid drainage is very noisy.

In addition, pipes that are not completely filled with water are filled with air, which behaves aggressively towards the pipe walls, thereby accelerating their corrosion. The second sad consequence of such an error is the overflow of settling tanks.

## What affects the slope of sewer pipes

The angle of inclination of the pipe depends on several factors:

**Pipe type**

- plastic (the surface of the plastic is smooth and even, which means they clog less, the drainage speed is faster. For this reason, the slope angle should be smaller);
- cast iron (durable, but their surface is rough, the permeability is lower. Therefore, when installing pipes, a greater slope is required).

**The diameter of the pipe**(depends on the amount of waste. The more water you drain into the sewer system, the larger it should be. A pipe that is too narrow will not be able to provide optimal throughput, as a result, the water will drain more slowly, the pipes will begin to silt and leak. An unpleasant odor will appear ).

## What should the slope be?

Rules for calculating roof slope

How to understand what a pipe slope is? In SNiP it is written in fractions - in the form of decimals. It will look like this: 0.03 or 0.008. The numbers are deciphered as follows: this is the difference in heights of the two ends of a meter-long piece of laid sewer pipe. The number 0.03 means that one end of the meter pipe is raised by 3 cm. Accordingly, the number 0.008 means that one edge is raised by 0.8 cm or 8 mm.

Recommended slope of sewer pipes of different diameters (50 mm, 100 mm, 150 mm)

The pipeline is usually much longer than one meter. You can calculate how much higher one end should be than the other by multiplying the selected slope by the length of the pipeline. For example, we will lay a sewer with a slope of 3 cm/m, its length is 25 m. This means that its far end will be lowered by 3 cm * 25 m = 75 cm.

### Dependence on pipe diameter

Sewage systems are divided into internal - installed in an apartment or house, and external - which are laid on the street. In both cases, it is necessary to maintain the required slope of the sewer pipe. When they say this, they mean the indicator recommended by sanitary standards. It depends on the diameter of the pipes used: the smaller the cross-section, the greater the slope must be given.

Diameter of sewer pipes | Normal slope | Smallest allowed |

50 mm | 0.035 (3.5 cm) | 0.025 (2.5 cm) |

100 mm | 0.02 (2 cm) | 0.012 (1.2 cm) |

150 mm | 0.01 (1 cm) | 0.07 (7 mm) |

200 mm | 0.008 (0.8 cm) | 0.005 (0.5 cm) |

The table shows the slope of the sewer pipe, which will ensure normal operation of the system. If for some reason it is not possible to make the required slope angle (this happens in areas with complex terrain), the slope angle can be reduced to the specified limit norm. The chance of getting problems increases, but not much.

### What to do if the slope is greater than required

Sometimes it is not possible to make the required slope - conditions vary. In this case, there are two solutions:

- Lay the pipe as best you can (but the difference per meter should not be more than 15 cm per meter) and hope that everything will work. If there is a large slope, it is recommended to install tees with upward bends on the route after a while - so that it is possible to clear blockages. The likelihood of their formation at large slopes of the sewer pipe is high.
- Lay the pipe with the recommended slope in such an area where this is possible, then install a drop well, and again take the pipe out of it at the required slope. Several such wells may be needed.

The first option is a cheaper device, but it involves frequent blockages in the pipes. Of course, with intensive use of sewerage (large amounts of water), there may be no problems, everything can work without problems. But this is rather an exception. By the way, when using plastic pipes, the likelihood of blockages becomes lower - they have smooth walls, on which precipitation rarely forms. The second option is more expensive and labor-intensive, but it guarantees the functionality of the system.

## How to set the correct slope angle of a sewer pipe

In order to set the correct slope, you do not need to reinvent the wheel. According to SNiP studies, the optimal speed for waste removal through sewer pipes with a diameter of 150 - 200 mm is 0.70 m/s. This is provided that the pipe is filled to 50-60%, but not less than ⅓. In this situation, normal removal of fat, small and large particles is ensured. The maximum permissible slope is 15 cm/m.

There is also a separate formula, thanks to which you can accurately calculate the required angle of inclination:

where: K is the coefficient for plastic (0.5) and metal (0.6) pipes; H is the degree of filling of the pipe; V—waste movement speed; d is the internal diameter of the pipe.

You can use the Callbrook-White formula:

**v=-2√2gDI*log_10 ((K/3.71D+2.5LV/(D√2gDI)**

v is the average flow velocity; g - free fall; D is the internal diameter of the pipe; I—hydraulic slope; K—pipe roughness; V is the viscosity of wastewater.

Source

## How to measure a slope using the example of a private house

It is easier to measure the slope in practice when you know the ratio of the height of the decline to the length of the pipe. Knowing the length of the sewer pipe, you can derive the total height of the slope by simply multiplying by 3. For example, the length of the pipe is 14 meters. So 14×3=42. 42 is the height difference between the extreme points of the entire pipe.

So to the question **“Is a slope of sewer pipes necessary when laying indoors?”**

the answer will be yes.

To simplify the calculation, we present the following slope data:

- Pipe diameter 50 mm – 2.5-3.5 cm per 1 m;
- Pipe diameter 110 mm – 1.2-2.0 cm per 1 m;
- Pipe diameter 125 mm – 1.0-1.5 cm per 1 m;
- Pipe diameter 160 mm - 0.8 cm per 1 m;
- Pipe diameter 200 mm - 0.7 cm per 1 m;

In addition, the pipeline should have as few butt joints as possible. After all, **the joint is a likely place for leakage**

.

Horizontal pipes must be placed facing the flow of wastewater in a vertical riser. The joint between a horizontal pipe and a vertical pipe can be 90°.

Avoid horizontal 90° joints. It is better to use two 45° fittings or three 36° fittings. If you need to use only one fitting, then it is better to take 67°.

If it is necessary to route horizontal pipes, use crosses or oblique tees. Equip the sewer with a drain pipe for ventilation. Install toilets as close to the riser as possible.

## Sewage pipe laying slope calculator

Transportation of wastewater through sewer pipes is most often carried out using the principle of gravity. That is, the highways are given a certain slope in the desired direction, and the water flows down under the influence of gravity, carrying with it all sewage contaminants. It would seem that there could be any questions here: place the pipe down at an angle - and be calm... It turns out that everything is not so simple - both insufficient and excessive slope can present extremely unpleasant surprises.

Sewage pipe laying slope calculator

Therefore, the pipe must be laid in strict accordance with the requirements specified in the Code of Rules. And all these interrelated parameters of the route - its diameter, length and slope - must be thought out and calculated in advance, even at the sewerage design stage. At the installation stage, correcting errors can sometimes be extremely difficult.

Planning will go faster if you use the proposed calculator for calculating the slope of laying a sewer pipe. Below are some comments on working with it.

## What is the pipeline inclination angle?

The installation of sewer pipes should not be carried out horizontally, but should be located at a slight angle to it, the value of which is determined by special standards. To indicate the slope of the pipe, an unusual system of degrees is used; here the coefficient is determined in centimeters per meter. This dimension allows you to avoid large errors when installing the main line to the septic tank. The length of such a branch can be 10-12 meters and it is very difficult to maintain a given angle. The proposed designation shows how much one end of a 1 meter long pipe should be higher than the other.

### Maximum slope

The upper limit of the permissible value should not exceed 0.15, this means a linear meter of pipe slope of 15 cm. A larger coefficient can be used in short sections adjacent to plumbing fixtures. It is necessary to take into account the flow speed; it cannot be more than 1.4 m/s, otherwise solid fractions will settle on the walls of the pipeline. Wastewater consists of numerous suspensions and particles with varying viscosity and fluidity. When the slope exceeds 15 cm, they separate - the liquid goes into the septic tank, and the remaining fractions silt up the pipe.

### Minimum slope

The minimum indicator is determined for each pipe section:

- 50 mm – 0.025;
- 100 mm – 0.012;
- 150 mm – 0.007;
- 200 mm – 0.005.

If these indicators are not observed, the pipeline will quickly become clogged. In certain sections of no more than 1 meter in length, a coefficient of 0.01 is allowed.

## Sewage pipe laying slope calculator

### Explanations for calculations

No special explanation is probably required. But still, a few words for the general concept.

As a rule, when creating a sewer system in a private house, they make do with a rather limited range of pipe diameters. Most often, the matter is limited to the “triad” - 50 mm, 110 mm and 160 mm, less often pipes ø 200 mm are used.

For each of these diameters, the optimal slopes have long been calculated, ensuring the principle of self-cleaning, when the draining water leaves virtually no contamination on the walls. That is, resort to the use of some complex formulas that take into account the filling of pipes, the roughness of their walls, the viscosity of liquids, etc. - there is no need.

According to the laying rules, sewer sections tend to be placed in a straight line, trying, where possible, to avoid changes in direction. And on such a straight horizontal section, changing the angle of the pipe slope is completely prohibited.

Setting each of the laid pipes at the required slope during their assembly, controlling its position, for example, with a building level, is tedious and unproductive. When making calculations and in direct preparation for laying, it will be much easier to mark the nearest and farthest points of a straight section (for example, from a turn to a tie-in into a riser, from an outlet to a well, between wells, etc.) and determine the height difference between these points, which will precisely set the required slope.

This height difference can, for example, be projected as a line on the wall - during interior work. And when laying a route in a trench, it is planned in advance and executed by digging out the soil and filling the sand cushion under the pipe. After such preparation, you can safely engage in installation, without being distracted by checking the position of each pipe section.

So, to find the height difference, in the calculator you will only need to select the diameter of the pipe in the calculated section (in millimeters), and indicate the length of this section (in meters). After clicking on the calculation button, the result in millimeters will appear.

The matter is usually not limited to domestic sewerage!

In a private country house, in addition to the domestic sewer, you also have to plug up the storm drain. Without it, maintaining comfortable living conditions is impossible or extremely difficult. Despite some similarities, these two systems still have more differences, and in no case should they intersect, complement or replace one another. how to create **a storm drain with your own hands** in a special publication on our portal.

Did you like the article? Save so you don't lose!

Source

## Sewer slope in a private house - do it yourself

It is customary to equip a modern private house with a drainage system. Even if the city sewerage line is located at a considerable distance, septic tanks are installed or special containers are equipped for their accumulation.

The rules for equipment of the sewer network are regulated by the same standards - the slope of the internal sewerage system by 1 meter according to SNiPs has the same values as the slope of the sewerage system in a city house apartment.

The same materials and elements are used for installing the internal network. The slope standards outside a residential building remain the same.

For the external sewer circuit in a private house, you can use pipes measuring 100 millimeters, and if there are a small number of people living in the house, it is possible to use 80 millimeters.

The pipeline is pulled through a trench with a depth not less than the freezing level of the soil. If this seems excessive (for the Moscow region this figure is 1.8 meters), you can install a less deeply insulated line or install a heating cable on the drain pipeline with automatic switching on when the ground temperature drops below zero degrees.

Requirements for the angle of inclination in a private house are subject to the same standards as for other devices.

All work on installing a drainage system for a country house can be performed as follows:

- Determine the required pipeline parameters for internal and external drain systems.
- Complete a preliminary design of the pipeline indicating reference to the horizon at various levels.
- Install the internal sewerage network in compliance with the requirements of SNiP. Exit the wiring from the interior through a short riser measuring 80 or 100 millimeters. The riser is subsequently connected through a corner passage to the outer part of the sewer.
- Dig a trench for laying the outer part. In this case, it is necessary to take into account the depth of soil freezing if the pipeline is not insulated according to the design. The depth of the trench is selected taking into account subsequent backfilling
- Place a layer of sand 15-20 centimeters thick at the bottom of the trench, compact it and pour water for better compaction. The level of the bottom of the trench when digging and the sand backfill in relation to the horizon is controlled using a water level.
- Install supports for the pipeline on the sand bedding. You can use concrete blocks or bricks for this. When installing, you must be guided by the requirement for a sewer pipe slope of 110 millimeters. The number of supports depends on the length of the trenches, and the distance between them is allowed no more than a meter. This is due to the fact that pressure from the soil will be exerted on the pipe, with which the trench is subsequently buried.
- After laying the pipe on the supports, it is necessary to check the functionality of the system by testing water through it. If the requirement for a sewer pipe slope of 100 mm is met and water passes through it without leaks, you can begin to close the trench. First, the pipeline is carefully covered with a layer of sand with its tamper on the sides and on top of it. Having closed everything completely, the trench is backfilled with previously excavated soil and the top layer of soil is reclaimed.
- When installing a complexly branched sewer drainage system on a site where there are additional sources of wastewater, the same rules for sloping sewer pipes in a private house are used. But there is a need to install inspection wells at the intersection of two or more systems. In this option, the depth of placement at the junction point is consistent with this factor for the main circuit, which leads the drains to the external space.

Correct sewer slope

If there is a branch of the city sewer near the house, it is advisable to connect your drain to it. To do this, you will have to obtain permission from the Gorvodokanal, which is in charge of the system, incurring certain costs. But in this case, subsequently there will be no need to spend on cleaning the septic tank or cesspool.

## Calculator for calculating sewer slope for a private house

It is difficult to imagine a modern house without a sewerage system. It is a necessary element of communications that ensures comfortable living.

There are 2 types of sewerage:

**pressure**(a pump is installed inside the drain pipes, which accelerates the removal of waste into the cesspool. In this case, the slope of the pipes does not matter);**gravity**(drain occurs under the influence of gravity. To ensure normal waste removal, it is necessary to install pipes at a certain slope).

## How to maintain the required slope

It is not enough to simply calculate the angle of inclination for a sewer system. When installing the structure, you must carefully observe this indicator, using a level with an inclinometer for control. In the absence of such equipment, use the usual level:

- A line with the preferred slope is drawn on the wall. Applying the device to the line, mark a point on the plastic in the place where the edge of the bubble is located. The pipes are installed so that the bubble is in the desired position.
- A lining of a certain width is attached to one side of the meter level. This method is suitable for long-distance pipelines; it is not used for short pipes.

When installing pipes, carefully observe the required slope, avoiding the formation of sagging or deflections. When installing drain pipes from any plumbing equipment, different slopes are followed.

When laying a pipeline indoors, the required slopes are marked on the wall, and then the pipes are aligned according to the drawing. In this situation, they do not focus on the floor level, but to control the work, they beat off a horizontal line on the wall with a level or use a bubble level. Having calculated the difference, they “lift” the distant end, then, after double-checking the correctness of the calculations and the drawn lines, they proceed to installation.

In bathrooms and toilets, the level is laid out with a thick sand-cement mortar. Then the pipe is finished with a plasterboard box, which is decorated with ceramic tiles.

Laying pipes in a groove is not always possible, since panel buildings have insufficient wall thickness. When laying the sewer pipeline from the kitchen, wedges and stands are used. Pipes laid at an angle are secured with special clamps every 40 cm.

## About the calculation of sewer networks

The speed of movement of the household-fecal environment, at which the self-purification effect is achieved, is mathematically calculated using the formula:

This mathematical formula is used to calculate domestic and industrial sewage systems. In particular, using the formula, the required slope of sewer pipes is calculated

**V**– speed of movement of the liquid medium, (not less than 0.7 m/s);**H/d**– filling capacity of the sewer pipe (at least 1/3 of the volume);**K**– resistance coefficient, depending on the pipeline material (0.5 – plastic, glass; 0.6 – others).

The practical work on the installation of domestic and industrial sewage systems allows for situations where the conditions calculated by the specified formula cannot be met due to the low flow of sewage.

In this case, it is recommended to install communications from pipes with a diameter of up to 50 mm with a slope of 3 mm per 1 meter of length. Pipelines with a diameter of 85 - 100 mm are laid subject to a slope of 2 mm per 1 meter of length. In any case, the maximum permissible value of the slope norm can be 15 mm per meter of length, but no more.

If the sewer system uses a tray mechanism for transporting wastewater, there is also a standard for this case. Thus, the filling level of trays should not exceed 0.8 times their height. The width of the sewer tray cannot be less than 200 mm.

Moreover, the width of the tray is set based on the calculation of the hydraulic properties of the system and the design features of this element. Thus, sewer trays with a height of more than 500 mm should not be less than 700 mm in width.

A tray sewer system, just like a pipe sewer system, is installed taking into account compliance with established slope standards. In addition, tray systems are constructed taking into account the dimensions of individual line elements - depending on the size of the height and width

Trays in sewerage construction are used in the construction of storm and drainage systems. You can learn about calculating the slope of drainage pipes in this article, which we highly recommend reading.

Wastewater filled with a high content of mechanical suspensions is discharged through sewer lines made with a slope, the value of which is also determined by calculation, taking into account the provision of self-cleaning fluid speeds in the pipes.

The filling of pipelines is normalized to 1/3 of their volume. Typically, this type of wastewater refers to industrial products, where particles of metals and other solids are mechanical suspensions.

## Standardization of the angle of inclination of the sewerage system per 1 linear meter

It seems natural to believe that exceeding the slope of the internal sewer can only have a positive effect, in which the wastewater reaches the collector faster.

But if water passes through the pipe too quickly, fibrous and solid inclusions are deposited on its walls, which gradually lead to blockages. Cleaning such a plug mechanically leads to a deterioration in the quality of the inner surface of the pipes, which aggravates the situation with free flow. The life cycle of such drain systems, as a rule, does not exceed one year.

The angle of inclination of a sewer pipe per 1 meter for pipes of different sizes has different standard values.

To get a complete picture of the operation of the domestic wastewater sewer system, we will follow the process from start to finish.

## Roof design features depending on the angle of inclination

If the project gives a roof slope, then calculating its height will not be difficult. And this parameter is one of the most important, because it determines the height of the ridge. This element of the roof structure is the starting point in the construction of the roof as a whole. Because during construction, the level of the ridge is first set, and lumber is cut to fit it: support posts. From here the length of the rafter legs is calculated.

The complexity of the calculation lies in the fact that not everyone remembers trigonometry, the formulas of which are used to calculate the lengths of roofing elements. The formulas are based on trigonometric functions: sine, cosine, tangent, catangens.

For example, how to determine the height of the ridge (and therefore the roof) using sine and tangent:

sin α = H/S, where “S” is the length of the slope. Accordingly, the height of the ridge will be equal to: H=S x sin α.

tg α = H / L, that is, H = lx tg α

In the same way, you can determine the length of the slope, or, knowing both parameters, you can calculate the angle of the roof. All design parameters are interrelated, so that, knowing two of them, the third can be determined.

By the way, when determining the parameters of the roof, you can do without the angle of inclination. For this, the Pythagorean formula is used. Here is its formula:

By swapping the values, the required value is found.

You may have a question related to the meaning of quantities of trigonometric functions. They are freely available, but so that you don’t look for them on the Internet and waste your time, we offer a table:

Values of trigonometric functions depending on the angleSource remont-kvartiri.livejournal.com

Let us add that trigonometric functions simplify the calculations of roofing structures. If you use them correctly and are able to sketch roof sketches on paper (having imagination in terms of the structural arrangement of its elements), then you can easily calculate the dimensions of each element.

This applies not only to single- or double-slope structures. It will also be easy to calculate the elements of hip or mansard roofs. You just have to break down their complex designs into simple ones.

## What does percentage slope mean and how to convert it to degrees

When we talk about the roof of buildings, the word “slope” refers to the angle of inclination of the roof shell to the horizon. In geodesy, this parameter is an indicator of the steepness of the slope, and in design documentation it is the degree of deviation of straight elements from the baseline. Slope in degrees does not raise any questions, but slope in percentage sometimes causes confusion. The time has come to understand this unit of measurement in order to clearly understand what it is and, if necessary, without much difficulty convert it into other units, for example into the same degrees.

Calculation of slope as a percentage

Try to imagine a right triangle ABC lying on one of its legs AB. The second leg BC will be directed vertically upward, and the hypotenuse AC will form a certain angle with the lower leg. Now we have to remember a little trigonometry and calculate its tangent, which will precisely characterize the slope formed by the hypotenuse of the triangle with the lower leg. Let us assume that leg AB = 100 mm and height BC = 36.4 mm. Then the tangent of our angle will be equal to 0.364, which according to the tables corresponds to 20˚. What then will be the slope as a percentage? To convert the resulting value into these units of measurement, we simply multiply the tangent value by 100 and get 36.4%.

How to understand the slope angle as a percentage?

If a road sign shows 12%, this means that for every kilometer of such ascent or descent the road will rise (fall) by 120 meters. To convert a percentage value into degrees, you simply need to calculate the arctangent of this value and, if necessary, convert it from radians to the usual degrees. The same goes for construction drawings. If, for example, it is indicated that the slope angle as a percentage is 1, then this means that the ratio of one leg to the other is 0.01.

Why not in degrees?

Many people are probably interested in the question: “Why use other percentages for the slope?” Indeed, why not just get by with just degrees. The fact is that with any measurements there is always some error. If degrees are used in design documentation, installation difficulties will inevitably arise. Take, for example, the same sewer pipe. An error of a few degrees with a length of 4-5 meters can take it in a completely different direction from the desired position. Therefore, percentages are usually used in instructions, recommendations and design documentation.

Application in practice

Let's assume that the construction project for a country house involves the installation of a pitched roof. It is necessary to check its slope in percentages and degrees if it is known that the height of the ridge is 3.45 meters and the width of the future home is 10 meters. Since the front of the roof is an equilateral triangle, it can be divided into two right triangles, in which the height of the ridge will be one of the legs. We find the second leg by dividing the width of the house in half.

-1

## Other installation standards (rules)

The provisions of the regulatory documentation affect both the characteristics of the equipment involved in the sewer system and the nuances of the installation itself.

### Closed communications equipment

For most cases of designing domestic sewer communications, the norms (rules) provide for the design of closed pipeline lines. This scheme traditionally works on the principle of movement of domestic and fecal water by gravity.

At some facilities (usually industrial), where wastewater is discharged without the presence of odors and dangerous fumes, it is permissible to carry out communications using gravity trays. In this case, it is necessary to equip the tray lines with a water seal device.

Sewerage pipelines are always laid in a straight line. To create turns, bends, and branches, additional installation elements are used. From the starting point of installation of the line to its complete completion, it is necessary to maintain a uniform change in slope according to calculations

If we consider the system in plan, then each individual section of sewer communications is installed strictly in a straight line. If it is necessary to change the direction of pipeline laying, standard mounting components are used (angles, crosses, tees, transitions, etc.).

It is unacceptable to change the calculated slope values of sewer pipelines on a separate section of a completed line mounted in a horizontal position.

Formation of the slope of the external sewer system

Laying from the exit from the house to the unloading/cleaning point

Arrangement of openly laid branches

Hidden pipeline installation

### Which pipes are suitable for the system?

In relation to sewerage networks (domestic, industrial), as well as with an emphasis on the properties of corrosion resistance and strength, various modifications of pipes are used for sewerage installation.

For communications made on the principle of gravity, the pipe materials are:

- polymer compounds;
- cast iron;
- concrete;
- glass;
- asbestos cement.

The criteria and rules for choosing pipes for external sewerage are given here. The information we recommend will be useful to all zealous owners of suburban areas planned for development.

For communications transporting liquids under pressure, pipes are made from the following materials:

Internal sewer lines are installed in one of two ways: open / hidden. Regardless of the installation method, polymer pipes are widely used in installation. Our recommended article will provide you with guidelines for choosing the best pipes for sewerage.

Plastic sewer pipelines may be laid in the ground below the floor level of buildings. But the load on the area with such communications should be taken into account.

The most common parts of sewer communications. Plastic pipes and all the necessary fittings are used in the construction of networks for various purposes. For owners of private property, this is an economical way to install sewerage in the house

Plastic fittings are considered universal and can be successfully used for internal and external networks.

### Features of installing risers

Installation of risers inside residential buildings is done in channels, shafts, and boxes. Their design must comply with fire safety regulations. Shafts, boxes, channels, etc. must be equipped with removable panels.

## Using calculated and optimal occupancy levels

Also, the fill level of a plastic, asbestos-cement or cast iron sewer pipe must be calculated. This concept determines what the flow rate in the pipe should be so that it does not become clogged. Naturally, the slope also depends on the fullness. **You can calculate the estimated fullness using the formula:**

- H – water level in the pipe;
- D is its diameter.

The minimum permissible SNiP 2.04.01-85 filling level, according to SNiP, is Y = 0.3, and the maximum Y = 1, but in this case the sewer pipe is full, and, therefore, there is no slope, which means you need to choose 50-60%. In practice, the estimated occupancy is in the range: 0.3

Slope of sewer pipes schematically

In the same way, it is easy to determine the slope of the external underground pipe. In most cases, external communications have large diameters.

Therefore, a larger slope will be used per meter. At the same time, there is also a certain hydraulic level of deviation, which allows you to make the slope slightly less than optimal.

To summarize, we will say that according to SNiP 2.04.01-85 clause 18.2 (standard for installing water drainage systems), when installing a corner of sewer pipes in a private house, **you must adhere to the following rules:**

- For one linear meter of a pipe with a diameter of up to 50 mm, you need to allocate 3 cm of slope, but for pipelines with a diameter of 110 mm you will need 2 cm;
- The maximum permissible value for both internal and external pressure sewerage is the total slope of the pipeline from the base to the end of 15 cm;
- SNiP standards require mandatory consideration of the level of soil freezing for the installation of an external sewer system;
- To determine the correctness of the selected angles, it is necessary to consult with specialists, and also check the selected data using the formulas above;
- When installing a sewer system in a bathroom, you can make the filling coefficient, and therefore the slope of the pipe, as minimal as possible. The fact is that water comes out of this room predominantly without abrasive particles;
- Before starting work, you must make a plan.

## What is the roof pitch angle measured in?

The designation of the roof slope on the drawings can be either in degrees or as a percentage. The roof slope is indicated by the Latin letter i.

In SNiP II-26-76, this value is indicated as a percentage (%). At the moment, there are no strict rules for indicating the size of the roof slope.

The unit of measurement for roof slope is degrees or percentages (%). Their ratios are shown in the table below.

### Roof slope degree-percentage ratio

degrees | % | degrees | % | degrees | % |

1° | 1,75% | 16° | 28,68% | 31° | 60,09% |

2° | 3,50% | 17° | 30,58% | 32° | 62,48% |

3° | 5,24% | 18° | 32,50% | 33° | 64,93% |

4° | 7,00% | 19° | 34,43% | 34° | 67,45% |

5° | 8,75% | 20° | 36,39% | 35° | 70,01% |

6° | 10,51% | 21° | 38,38% | 36° | 72,65% |

7° | 12,28% | 22° | 40,40% | 37° | 75,35% |

8° | 14,05% | 23° | 42,45% | 38° | 78,13% |

9° | 15,84% | 24° | 44,52% | 39° | 80,98% |

10° | 17,64% | 25° | 46,64% | 40° | 83,90% |

11° | 19,44% | 26° | 48,78% | 41° | 86,92% |

12° | 21,25% | 27° | 50,95% | 42° | 90,04% |

13° | 23,09% | 28° | 53,18% | 43° | 93,25% |

14° | 24,94% | 29° | 55,42% | 44° | 96,58% |

15° | 26,80% | 30° | 57,73% | 45° | 100% |

You can convert the slope from percent to degrees and vice versa from degrees to percent using an online converter:

### Roof slope measurement

The slope angle is measured using an inclinometer or mathematically.

An inclinometer is a rail with a frame, between the slats of which there is an axis, a division scale, and to which a pendulum is attached. When the staff is in a horizontal position, the scale shows zero degrees. To measure the slope of the roof slope, the inclinometer rod is held perpendicular to the ridge, that is, at a vertical level. On the inclinometer scale, the pendulum indicates the slope of a given roof slope in degrees. This method of measuring slope has become less relevant, since various geodetic instruments for measuring slopes have now appeared, as well as drip and electronic levels with inclinometers.

### Mathematical calculation of slope

You can calculate the roof slope without using geodetic and other instruments for measuring the slope. To do this you need to know two sizes:

- Vertical height (H) from the top point of the slope (usually the ridge) to the level of the bottom (eaves)
- Layout ( L ) - horizontal distance from the bottom point of the slope to the top

Using mathematical calculation, the roof slope is found as follows:

The slope angle i is equal to the ratio of the roof height H to the ground level L

In order to express the value of the slope as a percentage, this ratio is multiplied by 100. Next, to find out the value of the slope in degrees, we translate using the table of ratios located above.

To make it clearer, let's look at an example:

Laying length 4.5 m, roof height 2.0 m.

The slope is: i = 2.0: 4.5 = 0.44 now multiply by × 100 = 44%. We translate this value according to the table into degrees and get - 24°.

### Minimum slope for roofing materials (coatings)

Roof type | Minimum roof slope | ||

in degrees | V % | in the ratio of the height of the slope to the foundation | |

Roofs made of rolled bitumen materials: 3 and 4 layers (fused roofing) | 0-3° | up to 5% | until 1:20 |

Roofs made of rolled bitumen materials: 2-layer (fused roofing) | from | 15 | |

Seam roofing | from 4° | ||

Ondulin | 5° | 1:11 | |

Corrugated asbestos cement sheets (slate) | 9° | 16 | 1:6 |

Ceramic tiles | 11° | 1:6 | |

Bituminous shingles | 11° | 1:5 | |

Metal tiles | 14° | ||

Cement-sand tiles | 34° | 67% | |

Wooden roof | 39° | 80% | 1:1.125 |

## How to choose a slope

To determine what the minimum pipe slope should be that will be optimal for you, you need to know the length of the entire sewer system. In reference books, data is used immediately in ready-made form, they are depicted in hundredths of an integer. Some employees find it difficult to navigate such information without explanation. For example, information in directories is presented in the following form as in the figures below:

Table: required slopes and diameters of pipes for drainage Table: slopes of drain pipes in the apartment

### Minimum and maximum sewerage slope per 1 linear meter according to SNiP

Below is a picture that shows the minimum slopes depending on the diameter of 1 meter of pipe. For example, we see that for a pipe with a diameter of 110 the slope angle is 20 mm, and for a diameter of 160 mm it is already 8 mm and so on. **Remember the rule: the larger the diameter of the pipe, the smaller the slope angle.**

Examples of minimum sewerage slopes of 1 meter according to SNiP, depending on the diameter of the pipe

For example, a slope for a pipe with a diameter of up to 50 mm and a length of 1 meter needs 0.03 m. How was this determined? 0.03 is the ratio of the height of the slope to the length of the pipe.

### Sewage pipe slope 110 mm for external sewerage

Suppose you need to calculate the optimal slope for a common 110 mm pipe, which is used mainly in external sewage systems. **According to GOST, the slope for a pipe with a diameter of 110 mm is 0.02 m per 1 linear meter** .

To calculate the total angle, you need to multiply the length of the pipe by the slope specified in SNiP or GOST. It turns out: 10 m (length of the sewer system) * 0.02 = 0.2 m or 20 cm. This means the difference between the installation level of the first point of the pipe and the last is 20 cm.

### Calculator for calculating sewer slope for a private house

I suggest you test an online calculator for calculating the slope of sewer pipes for a private house. All calculations are approximate.

Pipe diameter | |

Exiting the house below ground level | at a depth of cm |

The depth of the pipe entry into the septic tank or central sewer system | cm |

Distance to septic tank i.e. pipe length | m |

The diameter of the pipe refers to the diameter of the pipe that leads directly to the drainage pit or general sewer system (not to be confused with the sewer system).

PS All questions and suggestions regarding this calculator can be asked below in the comments to this article.

## Laying sewer pipes

Laying a sewerage pipeline with a slope is only part of the requirements for the overall installation of a sewerage network. You should also take into account the standards established for laying pipes, based on the risks of damage and destruction.

These standards are determined by the effect of temporary and permanent loads on communications. For example, for domestic conditions, laying sewer pipes inside buildings is carried out to a depth of at least 100 mm, if the floor surface and the upper outer wall of the sewer pipe are taken as the measurement points.

It is recommended to protect domestic sewerage pipelines installed in places of possible mechanical stress by limiting direct access to them. For these purposes, protective nets, trays, channels, etc. are used.

If the pipeline is located below the level of seasonal freezing of soil layers, sewer pipe insulation technology should be used. Rigid polyurethane foam quite claims to be a modern insulation material. Sewer pipes are also insulated with mineral wool with preliminary waterproofing.

One of the possible options for thermal insulation of a sewer line. Various materials can be used for thermal insulation of domestic sewerage pipelines, but priority is always given to thermal insulators with low flammability properties or none at all.

When the location for laying communications is a trench, after developing it with a calculated slope and before laying the pipes, it is recommended to compact the soil. Soil compaction work is carried out on the bottom of the trench along its entire length.

The soil must be compacted to a depth of at least 200-300 mm. After these measures are completed, gravel is poured into the trench with a calculated slope, or trays are laid and sewer pipes are placed in the trays.

## Advantages of flat roofs

Online roofing calculator: subtleties of calculation and checking the results

The main advantage of a flat roof is its simplicity and cost-effectiveness of construction. Such a surface is convenient and safe, allowing maintenance or repair work to be carried out in optimal conditions. The surface area of such a roof is significantly smaller than that of pitched structures, which allows significant savings on roofing material.

An additional advantage of flat roofs is the convenience and ease of installation of various technical devices and equipment on them - satellite dishes, solar panels, etc. simplifies the repair and maintenance of equipment, which can be carried out at any time of the year.

Flat roof Source ivd.ru

There are flat roofs, the surface of which is equipped for lawns, swimming pools, recreation areas and other areas. In these cases, the use of the surface is most effective, although it requires significant costs for the design and maintenance of the sites.

Green roofSource archilovers.com

## What does the slope of the roof depend on?

- From the ability of the roof to protect the structure from external factors and influences.
- From wind - the greater the roof slope, the greater the value of the wind loads. With steep slopes, wind resistance decreases and windage increases. In regions and places with strong winds, it is recommended to use a minimum roof slope to reduce the load on the supporting roof structures.
- From the roofing covering (material) - For each roofing material there is its own minimum angle of inclination at which this material can be used.
- From architectural ideas, decisions, local traditions - this is how in different regions preference is given for one or another roof structure.
- From atmospheric precipitation: snow loads and rain in the region. On roofs with a large slope, snow, dirt and leaves will not accumulate in large quantities.

## Types of roofs and choice of their material

For each building the roof slope is individual. There are three types of roofs:

**flat**_ They do not have strict horizontality. The tilt angle is not less than 3º. Such roofs are equipped with special funnels for draining water, the walls of which are inclined by 1.5º;

Photo: funnel for draining water

**high**. Such surfaces are strongly influenced by the wind, and under its pressure there is a possibility of the roof falling off;

Photo: houses with high roofs

**flat**_ On very flat roofs there is also a risk of the covering being blown off by the wind.

Photo: house with a flat roof

The roof angle parameter depends on the degree of flatness of the slope and the roofing material used. As the slope increases from 11º to 45º, the pressure force increases 5 times. Based on the intensity of wind loads for the area:

- with low air speed, the slope of the roofs is 35-40º;
- with strong winds this figure is 15-25º.

If the overlap angle is 50º, in winter the snow will slide off the roof under its own weight, thereby eliminating its intense pressure on the roof.

Photo: overlap angle 50º

Based on the level of slope of the slope, the material is selected and the required number of layers for installation is determined:

- Rolled types of roofing material are used for roofs with a slope of 0-25%, while a three-layer coating is used for a slope of 0-10%, and a single-layer coating for a slope of 10-25%, but the main material is supplemented with topping.
- Asbestos-cement slate modification is used for roofs with a slope of no more than 28%.
- For steel sheets, the slope should not be more than 29%.
- The slope for tiles is more than 33%.

Photo: rolled view of roofing material, slate, galvanized corrugated sheet and ceramic tiles

## Conclusions and useful video on the topic

Interesting and educational thoughts about the correct slope of the sewer pipe:

Organizing household wastewater is not as simple a matter as an inexperienced layman might imagine. Professionals in the field of housing and utility communications know: it is necessary to calculate the laying of sewer networks in each case of their construction, regardless of whether the installation is being carried out for a private home or an industrial system is being built.

Please write comments, ask questions, post photos in the block below. Tell us about how you laid sewer lines on your own suburban area, and whether they followed the slope specified by the standards. It is possible that your advice will be useful to site visitors.

## External sewerage

Ditches are specially dug for external sewerage. They try to lay the route as straight as possible, since an excessive number of turns cause blockages.

If bends in the pipeline are unavoidable, tees are installed nearby, leading the pipe slightly above the ground and sealing it with a special hermetic cap.

Trenches for street sewerage must have a flat bottom and a depth of 20 cm more than required. A sand cushion is placed on the additional space. If the sewer system is not very long and has a slight drop, the bottom is left flat. If there is pronounced unevenness, an approximate descent is made. After this, the bottom is leveled, roots, stones, and other debris are removed. The existing holes are filled and compacted well:

- sand with a total thickness of 20 cm is placed on the prepared bottom;
- the sand cushion is gradually poured in layers of 5 cm;
- each layer is carefully leveled, compacted by pouring water;
- A total of four layers will be required;
- pipes are laid on the sand, adhering to the required slope;
- The correctness of the inclination is checked with a 1.5-2 meter building level or a long, even beam, attaching a bubble level to its middle;
- after laying the pipeline is completed and the slope is checked, the pipe is half filled with sand, which is leveled and watered;
- after compacting the sand, 1/3 of the pipe should be in the sand layer, and the rest should be covered with earth.

## Taper value

When considering taper, it should be taken into account that this indicator is directly related to the slope. This parameter determines the deviation of a straight line from a vertical or horizontal position. However, a 1:3 taper or a 1:16 taper is significantly different. The definition of slope is characterized by the following features:

- Slope refers to the ratio of the opposite side of a right triangle to the adjacent side. This parameter is also called the tangent of the angle.
- The following formula is used for calculation: i=AC/AB=tga.

This indicator can be calculated in a variety of ways; the most widely used formula is K=D/h. In some cases, the designation is carried out as a percentage, since this variable indicator is used to determine all other parameters.

When considering the 1:7 taper and other indicators, you should also take into account the features of displaying information in the drawing. Most often, such a mapping is carried out when creating technical documentation in the mechanical engineering field.

## Calculation of the slope angle to the horizon

It can be simply measured with an inclinometer, which is a bar with a frame with a pendulum with an arrow showing the degree value. But today this device is no longer relevant, since there are many drop and electronic inclinometers with much greater measurement accuracy and ease of use.

In the absence of geodetic measuring devices, there is a simple mathematical method that allows you to relatively accurately calculate the angle of inclination of the rafters. To do this, use a tape measure and a plumb line. A plumb line is lowered from the ridge to the floor of the building and the height h is measured. Then, from the point at which the plumb line touched the ceiling under the ridge, we measure the distance to the bottom point of the slope - position l.

The angle of inclination of the roof depends on the material chosen for the roof.

The angle of inclination of the slope i is equal to the ratio of the height of the ridge to the foundation (with the same units of measurement) i = h:l. In this case, the slope is expressed by a ratio that shows to what height the roof rises over the course of a unit of laying (how many meters the upper edge of the roof will be raised on one meter of horizontal flooring). To calculate the same slope as a percentage, multiply the resulting ratio by 100%. If you need to know this value in degrees, we translate it using a table.

For example: roof height h = 3.0 m, laying length l = 6.5 m. Then i = h:l = 3.0:6.5 = 1:2.17. This is an example of measuring slope by ratio. i = 3.0:6.5 = 0.4615. In percentage terms, this value is calculated by multiplying it by 100%: i = 0.4615. 100% = 46.15%. To determine the angle in degrees, we translate from the table and get 25º. If there is a need for a more accurate degree value, then from the resulting ratio, using a calculator or special tables, we calculate the cotangent, which will be equal to 24.78º.

It should be noted that a slope of 100% is when the roof height is equal to the pitch, that is, it corresponds to a 1:1 ratio or a slope angle of 45º. But you should not think that the percentage value of the slope and its degree value have a direct relationship. After all, the percentage slope is the value of the tangent of the angle at the bottom point of the slope, multiplied by 100%, and the graph of the tangent (tangent) has never been a straight line. And if 100% is 45º, then 50% is not 22.5º, but about 27º (more precisely 26.56º).

https://youtube.com/watch?v=kpnzjnJhgbQ%26feature%3Dshare%26list%3DPLxGukzvbwLed88MOnNdM0yBnuDYcVUW8H%26index%3D4

## Units of roof slope angle measurement

What angle of inclination of a pitched roof (gable, hipped, etc.) is accepted can be indicated in:

In this case, degrees mean an angle to the horizontal, a percentage or a fraction - the ratio of the height of the ridge to half the width of the roof (in construction the term “laying” is used).

Measuring the roof angle

Measurement in degrees is relatively inaccurate, giving (depending on the instrument used) an error of up to 5% in the angle and up to 10% in the linear dimensions of the structure during calculations. More accurate results are obtained by measuring as a percentage, with an angle of 45 degrees being taken as 100%.

For more convenient use of both measuring systems, a table is provided that allows you to convert the roof slope angle (degrees) into percentages and vice versa.

The standard scheme is used for calculation:

With these parameters, the percentage expression of the roof angle is 5:8 x 100% = 62.5%, in degrees this value will be approximately 32o, in fractional expression - 5:8 = 1:1.6.

For a better understanding of how and with what tools the roof slope is measured, and how to calculate the roof slope, we suggest watching the video.

## Type of roof covering and roof angle

To give you an idea of the upper and lower permissible limits of the roof angle using a particular roofing covering, we have developed a special table. The study of various regulatory documents, as well as observations during construction work, allowed us to draw conclusions about the conditions for using various roofing materials.

However, it is worth remembering that the construction market is rapidly filling with new materials, and the performance qualities of existing roofing coverings can improve with the development of modern technologies. Therefore, over time, the strength of some materials may increase, and as a result, the angle of the roof may change.

### Lower limit of roof angle

Slate (medium profile/reinforced profile) | 11/13 | 1:10 / 1:5 | 10% / 20% | 6° / 11,5° |

Pulp-bitumen sheets | 6 | 1:10 | 10% | 6° |

Corrugated sheeting (single-seam) | 3-6,5 | 1:4 | 25% | 14° |

Soft roll roofing | 9-15 | 1:10 | 10% | 6° |

Corrugated sheeting (double-seam) | 3-6,5 | 1:5 | 20% | 11,5° |

Metal tiles | 5 | 1:5 | 20% | 11,5° |

Ceramic tiles | 50-60 | 1:5 | 20% | 11,5° |

Cement tiles | 45-70 | 1:5 | 20% | 11,5° |

As for the maximum angle of inclination of the roof, for such lightweight roofing materials as cellulose-bitumen coatings, soft roofing, metal tiles and corrugated sheets, it can be even more than 1:1. You can see the maximum slope of all other roofing coverings in the table below.

### Upper limit of roof angle

Slate (medium profile/reinforced profile) | 11/13 | 1:2 / 1:1 | 50% / 100% | 27° / 45° |

Ceramic tiles | 50-60 | 1:0,5 | 200% | 64° |

Cement tiles | 45-70 | 1:0,5 | 200% | 11,5° |

So that you can easily and quickly convert the degree measure of an angle into a percentage, you can use the proposed table.

1 | 1,8 |

2 | 3,4 |

3 | 5,2 |

4 | 7,0 |

5 | 8,8 |

6 | 10,5 |

7 | 12,3 |

8 | 14,1 |

9 | 15,8 |

10 | 17,6 |

11 | 19,4 |

12 | 21,2 |

13 | 23,0 |

14 | 24,9 |

15 | 26,8 |

16 | 28,7 |

17 | 30,5 |

18 | 32,5 |

19 | 34,4 |

20 | 36,4 |

21 | 38,4 |

22 | 40,4 |

23 | 42,4 |

24 | 44,5 |

25 | 46,6 |

26 | 48,7 |

27 | 50,9 |

28 | 53,1 |

29 | 55,4 |

30 | 57,7 |

31 | 60,0 |

32 | 62,4 |

33 | 64,9 |

34 | 67,4 |

35 | 70,0 |

36 | 72,6 |

37 | 75,4 |

38 | 78,9 |

39 | 80,9 |

40 | 83,9 |

41 | 86,0 |

42 | 90,0 |

43 | 93,0 |

44 | 96,5 |

45 | 100,0 |

## What does the slope of the roof depend on?

- From the ability of the roof to protect the structure from external factors and influences.
- From wind - the greater the roof slope, the greater the value of the wind loads. With steep slopes, wind resistance decreases and windage increases. In regions and places with strong winds, it is recommended to use a minimum roof slope to reduce the load on the supporting roof structures.
- Roofing covering (material) - For each roofing material there is its own minimum angle of inclination at which this material can be used.
- From architectural ideas, decisions, local traditions - this is how in different regions preference is given for one or another roof structure.
- From atmospheric precipitation: snow loads and rain in the region. On roofs with a large slope, snow, dirt and leaves will not accumulate in large quantities.

## How to control the slope

For an example of installing an external main, let’s take the installation of a single straight pipe leading from the building to the septic tank.

**The purpose of the pipe is to transport sewage coming from plumbing fixtures to a common reservoir. This includes greasy waste from the kitchen sink, fecal matter from the toilet, and dirty water from the shower. **

It is reasonable that the pipe must have a cross-section of at least 110 mm. It is important for us that the required slope is maintained throughout the entire length of the pipe, in this case 0.02 m/linear meter.

Using a laser level, you can measure the slope angle at different stages of work. The photo gallery will help to visually represent the controlled work areas.

If the angle of inclination is maintained in all places, there will be no problems with the movement of sewer water. However, it should be remembered that the result of undetected errors in the future may be the complete dismantling of the external line, so each measurement must be taken very seriously and not done “by eye”.

## Methods for calculating percentage slope

The unit of measurement for roll, depending on its magnitude, is degree, percentage, ppm - a thousandth of a whole number: 1‰ = 1/10% = 1/1000 of 1. The physical meaning of slope is the ratio of the height difference to the length of the section on which it observed. In fact, it is the tangent of the angle: the excess of 12 meters on a section of the road of one hundred meters is expressed by the value 0.12 (tangent) = 12% = 120 ‰. That is, to calculate the slope in ppm, you need to multiply the percentage by ten.

When carrying out planning work on a land plot, it is necessary to resort to measuring the steepness of the slopes. This can be done in several ways:

- With the help of a level, all the necessary measurements are taken, and then, using simple calculations, the slope is formed as a percentage. How to calculate: the height difference is divided by the distance between the measurement points, and the result is multiplied by one hundred percent.
- According to the plan of the land plot, if there are relief marks on it. The height difference between the required points is read from the drawing, and the distance is measured with a scale ruler. Further calculations are similar to the previous method.

Roofers are often faced with the need to determine the actual slope of a roof and know how to calculate the slope using a special tool called an inclinometer. The design of the device is simple: a frame is attached to the rail with a protractor and a pendulum fixed inside, which has a weight and a pointer. The base of the device is placed on the lower surface of the roof section being measured, and the arrow indicates the angle.

## Slope calculator

**Slope calculator**

will help you calculate the slope, elevation or distance at the right time without any problems.

The calculator can calculate **the roof slope**

.

**pipeline slope**

.

**slope of the stairs**

.

**road slope**

, etc. It is also possible to calculate the elevation between points or the distance from point to point (useful in geodesy).

*Operating procedure:*

1. Select the value that you need to calculate2. Select in which unit of measurement you want to set/calculate the slope (3 types to choose from: degrees, ppm, percent)3. Set the 1st unknown4. Set the 2nd unknown5. Click the “Calculation” button

*For reference:*

- slope in degrees is calculated using the tangent of the angle:

**tgx = h / L**

- slope in ppm is calculated using the following formula:

**x = 1000 * h / L**

- slope in percentage is calculated using the following formula:

**x = 100 * h / L**

**Slope calculator**

created as an addition to the main online calculations on the site, and if you liked it, then do not forget to tell your friends and colleagues about it.

## Execution of work

After all the preparatory work has been completed, you can proceed directly to installation. First of all, you need to disassemble the old system. The work is carried out as follows:

- First, problem areas are identified where additional work will have to be carried out. This could be where the pipe goes through the wall.
- Using a chisel, the dismantling of cast iron pipes begins. In this case, cast iron must not be allowed to enter the main line of the sewer system. Otherwise, it may malfunction.

Working with cast iron sewerage is not the most aesthetically pleasing sight. Source domvpavlino.ru

If replacement of the main riser is not expected, then the pipe from it is sawed off using a grinder.

After dismantling has been carried out, work stops until the connecting units cool completely.

Installation of modern plastic pipes can be done in two ways.

### Installation of plastic pipes using glue

- pipes are cut into pieces of the required length;
- the edges are cleaned with sandpaper;
- the edges are degreased;
- pipes are checked for compatibility;
- glue is applied in the right places;
- the processed elements are connected to each other;
- when two pipes are compressed, a roll is formed, reminiscent in color of liquid honey;
- The glue dries within an hour.

## How to calculate the degree of fullness of a pipeline

For the stable operation of the sewerage system, the following indicators are important:

- wastewater flow velocity V;
- filling the sewer system K.

H – wastewater level height;

D – sewerage section.

By calculating the level of filling of the main, you can determine the optimal flow rate at which the system will function without silting and debris blockages. The complete filling of the tube is 1, this disrupts the ventilation of the system and the water seals may break. The effective indicator is 0.5-0.6; if it drops to 0.3, then the liquid is not enough to wash off solid fractions. This coefficient depends on the material of the pipes; smooth plastic has less filling capacity than rough cast iron and asbestos cement.

## What factors influence the choice of roof slope?

Weather conditions significantly influence the choice of roof slope. The accumulation of atmospheric precipitation can lead to roof collapse or the appearance of dampness, which is a favorable environment for the development of fungus.

If the region is characterized by regular rainy or snowy weather, the roof slope is increased, which helps to quickly remove snow or water from its surface.

In steppe and other areas where strong winds are frequent, it is necessary to correctly calculate the slope, since a very high roof can collapse under the pressure of the wind, and an excessively flat roof can be torn off by a strong blow.

The optimal values are considered:

- for rainy regions, the roof slope is 30-40 degrees;
- for areas with strong winds – 15-25 degrees.