To protect the upper part of the casing from frost, precipitation and vandals, craftsmen prefer to mount a caisson for a well made of brick, concrete, reinforced concrete rings or polymer. You can do the work yourself, knowing the basic principles and stages of camera installation.
Types of homemade caissons
A master can make a special chamber for placing pumping equipment, automation, a hydraulic accumulator in it from the following materials:
- Reinforced concrete rings. This option is good only because with a high ground level and strong heaving of the soil, the camera will not budge due to its mass. But here it is important to take into account that the joints of the rings often have fistulas. The caisson will be periodically heated. The installation of such a protective chamber will require serious costs: delivery of reinforced concrete elements, rental of special equipment for their installation.
- Monolithic concrete pouring. Considered to be more durable than ring construction. In addition, the work, although time consuming, is within the power of even one master. With proper reinforcement, the resulting concrete caisson will be strong, airtight, and durable. More often, such a chamber is made square due to the peculiarities of the formwork installation. As well as under the reinforced concrete rings, a solid foundation is needed under the concrete.
- Metal. Such a chamber is mounted less and less, since steel is prone to corrosion, and therefore to destruction over time. To avoid this, when installing a metal caisson, you will have to additionally process the material with special paints. In addition, the quality of the welded seams is not always ideal, which leads to the formation of fistulas and further flooding of the chamber.
- Brick. The best option for a caisson if the master wants to independently install the camera. This type is especially relevant if there are remnants of blocks from the built cottage on the site. The brick caisson is durable and reliable. The main thing is to treat its outer walls with bituminous mastic for complete sealing.
- Polymer. Here you can use a large barrel, or buy a plastic caisson with stiffening ribs. Plastic tanks are easier to work with than others. In addition, plastic caissons serve for 50 years or more.
Choosing the type of camera by the type of material, the master must rely on such criteria as the speed of installation, the cost of the process, the durability of the caisson, and certain difficulties in its construction.
Required tools and materials
If the master has decided to mount a monolithic concrete caisson, the following materials should be prepared:
- cement M-400 and higher;
- medium-fraction crushed stone (30 mm);
- river sand;
- reinforcing mesh or rods;
- bituminous mastic;
- formwork boards.
For the installation of a brick caisson, you should prepare:
- cement M-400 and higher;
- crushed stone (fraction 20-25 mm);
- river sand;
- brick blocks (the number of pieces is calculated according to the estimated width and height of the walls, divided by the width and height of one block);
- bituminous mastic.
Of the tools you will need:
- concrete mixer or a special pallet for manual mortar preparation;
- bayonet and shovel;
- rammer;
- roulette;
- hammer and nails;
- Master OK;
- mallet;
- buckets;
- building level;
- gas-burner.
For all other types of caisson (made of polymer or rings), the containers themselves, plus a shovel and a rammer, will be required.
Preparatory work
The initial stage in the installation of any caisson is the preparation of the foundation pit for it and the construction of the base. A hole is dug according to the dimensions of the future chamber plus 20-30 cm from all sides, including the bottom. As a result, the neck of the caisson should rise 20 cm above ground level. This makes it possible to exclude the ingress of atmospheric precipitation into the protective structure.
The bottom of the pit is well rammed. Pour a sand pillow with a layer of 10 cm and compact it well. If the installation of a concrete, brick or caisson made of reinforced concrete rings is envisaged, a cement platform with a thickness of 15-20 cm must be made. It is better to reinforce it. Once the base is ready, you can proceed with the installation of the caisson.
At the junction of the concrete slab with the casing, it is advisable to lay a waterproofing material. Before pouring the solution, the pipe must be treated with bitumen mastic or tightly wrapped with roofing material.
Stages of installing caissons with your own hands
A monolithic concrete tank is poured in this way:
- Formwork is installed on the prepared base, leaving 20-30 cm from the pit walls. You can drive the frame out of the boards gradually (30 cm each) or immediately to the full height.
- Reinforcement mesh is installed in the formwork.
- A solution is prepared from cement, sand and crushed stone in a ratio of 1: 3: 5, respectively. Loose ones are diluted with water to obtain a mixture of sour cream-like thick consistency.
- The prepared solution is poured in portions into the formwork and carefully tamped with a metal rod to drive out the remaining air.
- As soon as the tank is completely solidified, the formwork is removed and, using a perforator, holes are made in the walls for the outlet of cables and a water main. All technical gaps are filled with cement-sand mortar.
- The outer walls of the finished caisson are coated with bitumen mastic.
The top of the chamber can be equipped with a wooden board covered with roofing felt or a monolithic slab can be poured by first installing a wooden formwork made of solid boards. It is important to leave a hole in the slab for the hatch.
Caisson made of reinforced concrete rings
Since it is difficult to make a caisson for a well from concrete rings with your own hands, you will need the help of special equipment. Before installation, elements must be treated on both sides with bituminous mastic. After it dries, the rings are alternately lowered into the pit on a previously prepared base. It is advisable to coat all joints with polyurethane foam and, after it dries, go through with mastic again.
With the help of a perforator, technical side holes are made, and the gaps are sealed.
The top of the ring caisson can be a concrete slab with a hatch or just a welded metal shield.
Brick caisson
Taking into account the fact that the bottom of the pit has already been prepared (there is a concrete platform), strips of roofing material should be laid along the perimeter of the future masonry. Only after that they start laying. You need to lay the brick from the corner, moving to the opposite from one side and the other. The thickness of the solution between the blocks is 1-1.5 cm. It is important to install metal sleeves where the water supply pipes and cables are expected to be located. Then the walls of the caisson are driven out to the desired level.
As soon as the chamber is completely dry, it is plastered and coated with bitumen mastic from the outside and from the inside. After the waterproofing has dried, the chamber is backfilled.
The upper part of the caisson can be made of a ready-made concrete slab, a monolithic fill or a wooden board covered with roofing felt. A hatch must be made in it.
Polymer caisson
You can make a caisson for a well from a plastic barrel or buy a ready-made solid structure with stiffening ribs. The second option is preferable, since the tank will be able to withstand the pressure of heaving soil.
Often it is permissible not to make a powerful concrete base for the installation of a polymer tank. A sandy bedding with a thickness of 10-15 cm is enough.
Polymer caisson installation technology:
- The camera is installed on wooden beams, having previously formed a technical hole in the bottom for the casing.
- Carefully put the caisson on the pipe and lower it down.
- It is advisable to make additional holes on the surface for the output of pipes and cables.
- Backfilling of the polymer chamber is made from a sand-cement mixture. It is slightly moistened and compacted well in layers.
- It is better to place equipment in a plastic caisson 10 cm from the walls of the tank.
When constructing a protective structure for a well with your own hands, it is always worth considering the features of the site relief (the presence of rocky rocks) and the level of soil freezing in the region.
