Sealing the caisson from the inside. Which caisson waterproofing method should you choose?

The caisson protects the well and pumping equipment from extreme temperature changes. It also prevents groundwater from reaching important water supply points.

Poor waterproofing of the caisson can lead to pump failure, contamination of the wellhead and destruction of the entire structure. This issue needs to be carefully considered at the planning stage for future construction.

• Why is waterproofing needed?
• Methods Bitumen mastic
• Roll materials
• Asphalt mastic

Do-it-yourself waterproofing of a caisson

Sealing the caisson from the inside. Which caisson waterproofing method should you choose?

The waterproofing device is applied ready-made using the painting method.
You can also make the substance yourself. To prime the surface of the structure, it is necessary to apply: The mixture is applied to the surface in a solid layer, and where there are sharp iron corners, it is necessary to lubricate more thoroughly. To protect the metal structure from any damage, it must be left on a cast iron pad, and at the time of sprinkling with soil, the remaining areas must be sprinkled with sand.

To waterproof a metal caisson using the gluing method on the outside, you need roofing felt, roofing felt and glassine. They must be applied to the iron surface in a double layer. You can apply 4 layers, thus increasing the service life.

Asphalt waterproofing of an iron caisson from the inside is the most labor-intensive process, so it is better to immediately seek the services of craftsmen who will do the work inexpensively. This method has the highest cost. It represents the following process. It is necessary to pour hot asphalt mixture into the gap; this must be done carefully so as not to damage the interior of the structure.

If groundwater deposits are nearby, the caisson may float. In order to avoid this you need to:

• additionally load the structure from the inside or outside;
• or do not install the caisson under the house.

For those who do not have the slightest skills and knowledge in this area, it is better to immediately seek the services of specialists. The YouDo website contains many advertisements that are updated regularly. You can order professional work inexpensively. The price of the work depends on the experience and qualifications of the employee, but prices for such services are always affordable.

Types of Source Contamination Protection

The negative impact of impurities on water intake horizons is possible if the waterproofing of the well from groundwater was initially not done well enough or was subsequently damaged.

1. To protect against the flow of perched water into the lower layers, the annular cementation method is used. This is an integral part of the professional drilling process and is entirely dependent on the company performing the drilling.
2. Isolation of the wellhead from precipitation or flooding with groundwater is carried out by installing a protective inspection well - a caisson. This hydraulic structure is designed to ensure absolute tightness of the annular gap around the casing. Particular attention is paid to waterproofing caissons from inside and outside from groundwater, since in most cases a drop in water quality occurs when it is disturbed.

Caisson repair without welding. How to repair a caisson

I will not claim that I am all-knowing, but three methods of repairing a caisson have been tested in practice.

If the damage is local (there are several small corrosion pits), welding can be used. We will apply a gasket and patch to the damage, wedge it to eliminate the leak, remove the water, and if the welder is qualified enough and the bottom is not yet completely rotten, everything will work out. Verified.

Plumbers use choppers to temporarily repair pipelines, even under pressure.

If the ulcers are irregular in shape, they need to be calibrated with a drill of a suitable diameter. We make a conical chop from dry birch with a diameter slightly larger than the hole and hammer it in. If there is a “stump” of more than 5 mm left, carefully saw off the excess with a hacksaw.

Once swollen with water, the chop will stop the leak.

When you have dealt with the damage and removed the water, you need to fix the chop with a thick cement mortar with the addition of about 0.5 liters of liquid glass per bucket of mortar immediately before use - it sets quickly.

If the next day we are convinced that everything has been done correctly and there are no leaks, we lay a metal mesh on the cement tubercles and make a general screed with cement mortar or fine-grained concrete with the addition of a small amount of liquid glass.

I recommend making the same screed after welding, since the anti-corrosion protection on the outside has burned out, and the metal at the welding site has become more vulnerable to corrosion.

It is better not to wait for the start of a leak for those whose caissons have been in service for a long time, especially if they are in garage cooperatives located under high-voltage power lines.

If the bottom resembles a colander, radical measures are needed. You will have to dig out the top of the caisson and cut off the ceiling with a grinder or gas cutter, weld a metal liner 3-5 mm thick with dimensions 50-70 cm smaller than the caisson and 1400-1600 mm high.

Several pieces of cement mortar are placed on the bottom of the caisson and a liner is installed.

Stops must be welded to the walls of the caisson on all sides so that the liner does not float up.

Fill the sinuses with liquid cement mortar. Install and weld the top part.

It is better to do all repair work in early autumn, when the groundwater level is lowest.

Method of insulating a well with a head

If a well cap is installed on the well, the risk of equipment freezing increases. You can isolate a well with a head using a box. To assemble the box, you can use boards, mesh or rigid insulation.

The most reliable option: assemble a box from boards and line the inside with sheets of insulation. The volume of the box should not be less than one cubic meter. The finished box is put on the upper part of the casing and the well head.

The space inside the box is filled with mineral or glass wool. Filling the box with improvised materials is less reliable. But if you save your budget, you can use dry leaves, paper, hay and straw to fill the box.

How to repair a leaky caisson. How to fix a broken caisson

The purpose of the caisson is to protect the internal space of a well or reservoir from aggressive external environmental influences. However, over time, even the most durable material wears out. Repair of the caisson is required for any leakage that could cause a leak.

The main reasons for repairing a caisson

Metal structures are susceptible to corrosion and therefore require periodic repairs

In garages, this equipment is used as basements or inspection pits. They are sealed and can be installed in soil with any level of moisture saturation.

The caisson can be plastic, reinforced concrete or metal. The first type of structures is not subject to corrosion, but is easily deformed due to the displacement of soil layers and under strong liquid pressure, so their restoration is not cost-effective.

Reinforced concrete products are strong, but they consist of several volumetric parts. As a result, even a small pressure leak in the caisson is difficult to eliminate. A leak can lead to damage to the property inside, and replacement is associated with a lot of difficulties due to the large mass. Therefore, the optimal solution if repairs are necessary are restoration work that excludes radical measures.

Most often, installation of iron models is performed. Containers made of metal are easy to install, but quickly wear out at the weld joints. As a result of the development of the corrosion process, the tightness of the seams, and then the entire product, is compromised. Timely elimination of sources of damage extends the service life of the frame.

Repair methods

The hole in the caisson can be sealed with foam

An iron caisson is a round or square steel box with walls more than 4 mm thick and with ventilation ducts for removing condensate. Asphalt or bitumen-gasoline solution, as well as bitumen mastic, are used as a waterproofing layer. If the protection is performed poorly, over time holes appear through which liquid begins to leak.

It is possible to decide which method is best to use to eliminate the damage only after studying the cause of its occurrence, as well as analyzing the conditions of the general condition of the equipment. It must be taken into account that the tank inside of which repair work is planned has a limited size.

• The hole formed in the caisson can be repaired by applying a patch of roofing material or by cold welding. To do this, a wooden plug is inserted into the hole, which swells and tightly isolates the damaged area. After which the surface is dried, and roofing felt sheets are laid on it, secured with bitumen mastic. The structure is reinforced with mesh and filled with a mixture of liquid glass and cement mortar with a thickness of at least 150 mm.
• If several leaks are identified in the tank, this indicates the need for major repairs. The process is carried out in several stages: the top is cut off, a cement screed is laid on the floor, then a liner with parameters 5-7 cm smaller than the size of the bottom, everything is fixed with stops and the top is again filled with concrete mortar. After the screed has hardened, the upper part is welded into place.

To avoid having to perform labor-intensive restoration operations, you need to carry out regular inspections of the device.

Preventive measures

To waterproof a concrete caisson, you can use bitumen mastic

Timely detection of defects allows faults to be eliminated with minimal repair costs.

• The installation of structures is carried out on a sand and gravel cushion more than 20 cm thick. Sand is poured between the walls of the well or pit and the container. Breakdowns are most often the result of ignoring SNiP during installation, as well as standards regulated by GOST and TU at the production stage.
• You need to take care of the waterproofing of the installed container at the installation stage. The walls of the chambers must have sufficient strength characteristics to withstand the loads created by the movement and expansion of soil layers.
• To avoid corrosion processes, it is necessary to eliminate increased moisture formation. To do this, cold bridges in the thermal insulation coating are removed and an exhaust system is installed.
• Metal containers must have good roofing material or asphalt waterproofing and treatment with anti-corrosion compounds.
• Plastic tanks must be installed in well-drained sandy soils or special soil preparation must be carried out.

Preventative inspection of connecting seams for cracks, holes and other defects is best done in the spring. At this time, it is clearly visible whether the caisson in the garage needs repairs: a leak on the floor will be visible to the naked eye. Work is generally carried out when the groundwater level is at its lowest, in late summer or early autumn.

Methods

Before any work, the surface of the container must be thoroughly cleaned. Slag, burrs and small irregularities damage the waterproofing of the metal caisson. Then a compound is applied to the walls to prevent corrosion.

There are three ways to protect the caisson from water:

• Bitumen mastic. The most popular option. You can buy the necessary solution at the store or even cook it yourself.
• Asphalt mastic. A very labor-intensive method, but at the same time the most effective. It also protects the caisson from low temperatures.
• Roll materials. It will cost less than other solutions. You can use any roll waterproofing material, for example, roofing felt.

Bitumen mastic

If you decide to prepare the solution yourself, prepare a boiler for boiling bitumen. Its volume should be approximately three times the amount of substance. You will also need gasoline. It is not recommended to replace it with kerosene or other fuel.

After installing the boiler on fire:

1. Continue heating the container until foam appears on the surface of the solution.
2. Once ready, measure the required amount of gasoline. For primer you need three times more than bitumen. The first layer requires equal amounts of the two components. The following layers contain three times more bitumen than gasoline.
3. Gradually pour fuel into the bitumen mixture and stir. The solution is ready.

This mastic is suitable for interior work in a metal caisson. The composition should be applied evenly in several layers. Pay special attention to sheet joints and corners, as this is where the most liquid accumulates.

Roll materials

To protect the surface with sheets of waterproofing material:

1. Apply primer to the outside surface. Here you can use bitumen mortar; it perfectly bonds cement and roofing felt. It is necessary to form at least three layers of primer. Do not violate fire safety rules when handling gasoline.
2. Fill all uneven areas and potholes with a solution of cement and sand. You can add thickened PVA glue to the mixture.
3. Apply another layer of primer to the cement mixture and cover with bitumen.
4. Apply three layers of sheets of waterproofing material to the outer surface of the caisson. To do this, use a blowtorch. In this case, the seams of each new layer should be in a different place, that is, overlapping. Additionally, go over them with a blowtorch and bitumen mastic.

You can extend the life of sheets using brickwork. Do it after the final stage of work on the outside of the building. The bricks will press the sheets against each other due to their weight.

Asphalt mastic

Suitable for external waterproofing only. Before work, brickwork needs to be built around the well at a distance of about 20 cm. A special asphalt mastic should be poured into the cavity between the surface of the caisson.

This method is more difficult than others and requires a large number of workers. An inexperienced worker can only damage the housing through improper installation. This mistake will lead to the unusability of the cellar and large material waste.

Please note that if the tank is located in a swampy area, in the fall or spring the floor in it may fill with melt water. To eliminate this annoying mistake, load the cellar with additional materials.

Water in the caisson, what to do. Thermal insulation

To prevent the formation of condensation in the caisson, it is necessary to provide a highly effective thermal insulation layer on the walls, floor and even on the ceiling. Thermal insulation can be performed using a variety of insulation materials.

The main thing is that the selected material does not rot during use. In some cases, mineral wool, glass wool, synthetic or fiberglass blankets with filling, plaster or warm concrete are chosen for metal cellars.

Particular attention must be paid to the quality of fastening of the heat-insulating material on the walls of the cellar. For example, fastening can be done using hooks:

• Hooks are made of soft sheet steel, cut into strips of small length and width. Holes are drilled in the cut strips.
• The hooks are attached to the walls of the metal cellar using rivets, which will prevent moisture from penetrating through the holes formed. Hooks can also be secured by welding.
• A distance of 40-50 cm should be maintained between the hooks in the horizontal and vertical directions. The first row of hooks is mounted at a distance of 15-20 cm from the floor. Ideally, all hooks will be located along the same horizontal and vertical lines.

If the cellar leaks after installing the hooks, then it is recommended to additionally weld the fastening points on the outside. Water, even in small quantities, accumulating in the caisson will not allow vegetables and other products to be properly stored. Moisture penetration must be eliminated by any available methods. Maximum sealing of the cellar must be ensured using effective waterproofing materials.

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Waterproofing a steel caisson. Metal cellar - caisson

To store vegetables, fruits, and canning, you can build a concrete or brick basement. A more technologically advanced option is a caisson cellar. A caisson is a special underwater chamber, which subsequently found application in construction.

Design advantages:

• greater level of protection compared to a cellar. The sealed structure of a metal cellar can be installed in an area with a high groundwater level or lowlands;
• maintaining the required level of conditions that facilitate long-term storage of stocks without exposure to moisture;
• the design allows you to completely get rid of mold and mildew;
• A plastic or metal cellar with your own hands can be installed anywhere - under the house, veranda, garage, or made as a separate object. When placing a structure under a house, it is installed before construction of the building begins. It is convenient to place a metal cellar under the kitchen;
• is reliably protected from thieves, compared to a traditional cellar, so it is a good option for a country house rarely visited in winter;
• Properly performed waterproofing of the caisson will provide reliable protection against rain, groundwater, water supply and sewerage accidents, and the penetration of rodents.

Kinds

In practice, several types of caissons are used - steel, reinforced concrete, plastic. Which caisson is better? The most labor-intensive and expensive structure is considered to be one made of reinforced concrete rings; its installation requires a reinforced base.

Installation of the structure, sealing and insulation, compared to other types of caissons, is more complex; the ventilation device will require additional effort, since sawing and drilling reinforced concrete is more difficult. The dimensions of the building depend on the dimensions of the concrete rings, which are limited to a certain extent.

The plastic caisson is the lightest in weight. The cost of a plastic cellar is quite high, which can be about 20% more expensive than a metal one for the product alone. Often the dimensions are standard and this is not always convenient when building a cellar to your own requirements. Due to its light weight, the plastic box is sensitive to high groundwater levels. There have been cases of the caisson box being squeezed out of the soil.

Some manufacturers recommend installing two concrete slabs during installation - under the caisson and inside it to make the structure heavier. The plastic cube is equipped with a standard ventilation system. It is not recommended to alter the ventilation at your own discretion, so as not to compromise the tightness of the structure.

The metal caisson has a high level of reliability. The advantage of metal structures is that they can be given any shape and size. If you have the skills and tools, you can make a metal caisson yourself.

The cellar can be in the shape of a cube or cylinder with an entrance hole and a lid. For the manufacture of caissons, metal is used, the wall thickness of which is usually 10 - 16 mm, so that the structure can withstand the pressure of water and soil.

Additional insulation options

It may be interesting: Rules for operating a water well.

If you have already installed a caisson without thermal insulation, you can insulate it yourself. The following insulation materials are suitable for thermal insulation:

1. Expanded polystyrene, polystyrene foam, penoplex. Synthetic insulation materials that are similar in composition and contain up to 95% air. Insulation materials from this group are rigid and weakly absorb moisture.
2. Penofol or polyethylene foam. Available in the form of cylinders and sheets. Suitable for insulating pipelines or underground chambers. Has poor compression resistance.
3. Glass and mineral wool. These insulation materials absorb moisture very well, and when wet they lose their protective properties. Therefore, glass wool and mineral wool are rarely used for insulation of pipelines. These insulation materials can only be installed inside a protective box. Most often they are used for insulation of wells with caps.
4. Foamed polyurethane foam and penoizol. To apply these compounds you need special sprayers. The liquid composition is prepared from two mixed components. When the liquid hardens, a porous substance with a large number of air cells is formed. The finished surface is soft and uneven, but it repels moisture well.
5. Expanded clay. Lightweight porous stones produced by firing clay. Expanded clay is sometimes used to line caissons and trenches intended for water supply.

All of the methods listed do not provide an absolute guarantee of well protection, especially if you carry out thermal insulation yourself. The most reliable way to insulate a well on a site is to select and install a good caisson.

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Caisson for a well made of concrete rings: advantages and disadvantages.

Before installing the caisson on the well, a hole is dug, then a flat bottom base is made, then reinforced concrete rings are installed, a concrete cover is placed on the rings, and the whole structure is crowned with a hatch.

Advantages:

And then came the disadvantages:

• Heavy weight - you will need a truck and a manipulator to install it in the pit.
• Mandatory treatment of the rings with bitumen (waterproofing) - since concrete has a porous structure and allows water to pass through it. The waterproofing must dry, i.e. It will not be possible to install a caisson in one shift.
• Over time, the upper part of the caisson made of concrete rings is destroyed under the influence of temperature fluctuations.

Heating cable installation technology

To insulate pipes, it is not necessary to wrap them entirely with wires. It is enough to lay a section a few meters long to heat the pipeline for the winter. In most cases, installation is carried out inside the water supply.

High-quality heating electric cables are supplied complete with thermostats. Many manufacturers include three-inlet fittings. To connect the electrical cable, a ½-inch entry and a rubber sealing gland are also required.

How to properly insulate a water supply from the inside:

1. Assembling a tee from two pipes and an outlet for an electrical cable.
2. Assembling the input unit for the electrical cable. The parts are fastened with FUM tape.
3. Passing the wire through the gland to the selected length.
4. Securing the wire at the input with a clamping sleeve.
5. Installing a tee together with an electrical cable on the pipeline.
6. Connecting the heating wire to the outlet via an extension cord.

Using an electric cable makes it possible to heat water. Other insulation methods slow down the freezing time. The insulation scheme with electric cable works effectively even in severe frosts.

Let's build your dream home together

Do you know why a caisson is installed in a well? No. Then let's look at what they are and why they are needed.

Caissons for a well are a kind of cylindrical or parallelepiped-shaped structure into which a water well is hidden. They protect the well from freezing in winter and spring from the penetration of melt water. It should have a hatch on top to provide access, and a ladder if you want to get out of there