Methods for waterproofing a well, its types and reasons that necessitate these measures. Detailed technologies of work both on the existing and on the construction site. Well waterproofing is a set of measures aimed at increasing its tightness, which in turn contributes to the durability of the structure and maintaining an optimal liquid level in it. Today we will tell you how to do all this on your own in this article.
The need for insulation of wells and its types
Wells of household plots that need waterproofing, according to their purpose, can be classified as ordinary for drinking water, sewer and technical. In ordinary wells, the water is cleaner than in public mains. But over time, surface groundwater containing salts, chemicals, oil products, feces and other contaminants destroy the walls of such buildings, and liquids "rich" in these additives are no longer considered drinking.
In sewer wells, the pollution pattern is exactly the opposite. Here, groundwater must be protected from sewage penetrating through the walls of septic tanks.
Technical wells that are equipped with water fittings and sensors, by definition, must be dry. If the level of humidity in their mines is exceeded, it will soon lead to corrosion of devices and overgrowing of structures with moss and mold.
Waterproofing of any of the listed wells exists in two types: external, which, although more laborious, but the most effective, as well as internal.
If the tightness of the well is provided with waterproofing on the outside and inside, then such a procedure will protect it from destruction for a long time and will guarantee, depending on the functionality of the structure, high quality of drinking water, optimal humidity in its mine or protection of the soil from impurities.
External waterproofing of the well
The purpose of the external waterproofing of the well is to prevent the influence of groundwater on its walls. It is most reasonable to carry out this work during the construction of the structure, when the sinuses of the pit have not yet been filled with soil. At a later stage, it will be necessary to carry out excavation work in a significant amount in order to free the walls of the structure from the earth. External sealing of the well can be performed in three ways: using roll insulation, using insulating impregnation, by gunning.
Pasting with roll insulation
To work with an operating well, first, it is necessary to free its walls from the outside from the soil to a depth of 3-4 m. After inspection, loose areas of the structure's surface should be removed using a perforator, and the rest should be cleaned of dirt, mold, moss, chemical deposits and washed. For this procedure, you can use spatulas, metal-bristled brushes, a sander, etc. If the reinforcement is exposed during the cleaning process, the metal must be cleaned and covered with an anti-corrosion compound.
Before waterproofing the well with bitumen and roofing felt, a primer like "Betokontakt" should be applied to its walls from the outside. It will provide the required adhesion of the substrate to the insulating materials. In addition to the Betokontakt mixture, you can apply a bitumen-rubber suspension, applying it with a spray gun in 3 layers. However, the use of this material requires unmistakable adherence to fire safety regulations. Therefore, this method is not suitable for beginners.
After the primer has dried, you can start repairing the outer surface of the well shaft, if necessary. The procedure consists in sealing large potholes. In this case, you can use a thick mixture consisting of sand, cement and PVA glue. When the patches are dry, the walls of the well should be primed again.
At the last stage of work, the outer part of the structure must be covered with bituminous mastic and 3-4 layers of roll waterproofing material must be glued onto it. The joints of his canvases must be thoroughly greased with a sealing compound.
Coating waterproofing with impregnation
When using this method, instead of priming the walls, they are moistened with water. Then the outer part of the well must be coated with a protective deep penetration mastic. One-component waterproofing impregnation "Penetron" or "Elakor-PU Grunt-2K / 50" is suitable for this purpose. It should be applied 2 times and then left to dry for three days.
In order that during the drying process the coating waterproofing of the well is not covered with cracks, it must be periodically moistened, avoiding mechanical effects on the coating.
Shotcrete method of walls
To implement this method, you will need a special "gun", with the help of which it is necessary to apply a layer of cement 5-7 mm under pressure on the walls of the well. Then from 10 to 12 days you should wait until it grabs.
As in the previous case, the cement coating must be protected from cracking. To do this, in hot weather every 4 hours it must be watered with water, and in cool weather - every 12-14 hours. In a similar way, you need to apply another layer.
External waterproofing should be carried out up to the neck of the well. Then the space around it needs to be covered with a mixture of sand with gravel, soil, and then tamped. The perimeter or circumference of the structure must be equipped with a cement blind area, giving it a slight outward slope.
When installing external waterproofing of the well, it is recommended to make a clay "lock" around it, which serves to drain moisture from atmospheric precipitation from the walls of the structure. The material for it is clay, containing no more than 15% sand. You need to prepare it in advance. It will be good if the material lies on the street all winter and freezes. The ready-made mixture for a clay castle should contain lime, which should be added to the base material just before work in the amount of 20%. The resulting mass must be plastic and able to keep its shape. You can check this by placing a small amount in the palm of your hand - the mixture should not spread.
The depth of the earthen castle should be approximately 0.5 m, and the width - 1 m. For its construction, it is necessary to dig a pit, install a panel formwork in it, into which then put clay and lime in layers of 20 cm. After that, the place must be carefully tamped. From above, the lock can be covered with geotextiles and external finishing with paving slabs. Such a covering will be convenient for the operation of the well - during the rains, there will be no mess of mud around the source.
Internal insulation of the well
If for some reason it is impossible to waterproof the well with your own hands from the outside, it is done from the inside. For such a case, special cement-polymer compositions are used, the best of which is the ISOMAT system.
It includes:
- Megacret-40 is a repair compound that includes cement and polymer modifiers. The mixture provides excellent adhesion and absolutely no volumetric shrinkage. It is easy to work with it even for a master with little experience.
- Aquamat-Elastic is a two-component elastic compound. It is applied with a coating method, it is environmentally friendly. The finished cement-polymer coating on its basis has no negative impact on the quality of well water.
- Aquafix is a special cement-based compound that instantly hardens when it gets into water. Used to create hydraulic plugs - eliminates active leaks in problem areas of the walls of the well.
It is recommended to carry out work on the internal waterproofing of the well in stages in the following order:
- If the well is operational, before starting the insulation, it is necessary to pump out all the water from it and in the working process make sure that its level does not rise.
- Clean the walls of the structure from vegetation, sediments and dirt to be able to identify structural defects.
- The detected cracks must be cut to a depth of 20 mm and cleaned with a brush with a hard steel bristle; loose sections of the walls must be removed with a chisel or scraper, and then they must also be cleaned.
- The joints of the concrete rings of the structure should be expanded to a height of 30 mm. If this opens a leak, it can be repaired immediately by using Aquafix to create a plug.
- After cleaning and cutting, all potholes and grooves must be filled with Megacret-40 flush with the main surface of the walls and wait for the compound to set.
- When the repair mixture hardens, you can proceed directly to waterproofing the well from the inside. The surface of the walls of the structure should be slightly moistened and prepared with Aquamat-Elastic. Its consistency should be comfortable for applying the insulating material with a wide brush.
- The composition should be applied in 2 layers from bottom to top. The treatment of the walls of the well with the second layer can be done only after the first one has solidified, while the walls do not need to be moistened. The time of complete readiness of the coating is no more than 24 hours.
Protection of individual elements of the well
It is possible to seal the well not only when it is in operation, but also under construction. In this case, all its main elements are subject to waterproofing separately.
Well bottom insulation
If you need to build a technical well for installing equipment in it, a round plate with a ridge is laid on the bottom of the structure, which provides the centering of the first ring from the bottom. The resulting joint must be insulated. There are several ways to do this.
Before installing the lower ring around the circumference of its place, you need to lay a special waterproofing cord, for example, of the "Barrier" or "Gidroizol M" brands. The composition of the granules of these cords provides for the expansion of the material in volume by 3-4 times from the action of water. This leads to a reliable filling with insulation of all joints of the structure.
The communication well can be protected from moisture using roll material. The bottom of the structure, cleaned of dirt, must first be treated with a bituminous composition, and then pasted over with roofing material, placing its canvases with an overlap of 20 cm on the walls. Reliable waterproofing of a concrete well can be provided with three layers of material. After pasting, it is recommended to cover its bottom with a layer of crushed stone or gravel.
The joint between the bottom of the well and the bottom ring can be easily repaired with Megacret-40 repair mortar. First, it is necessary to apply one layer of the composition and immediately glue the entire joint around the circumference with waterproofing tape. When the repair mortar hardens, apply the Aquamat-Elastic mixture in 2 layers to the joint. After it dries, reliable insulation will be provided to the bottom of the well.
Insulation of concrete rings and joints
In order to avoid many problems after installation, the rings of the concrete well can be insulated ahead of time on both sides. The methods of such waterproofing are similar to those proposed above:
- External insulation - rubber-bitumen coating applied with a brush, or pasting with roll material;
- Internal coating - coating insulation with aquamat-elastic.
Thus, until the moment of installation, almost the entire surface of the precast well will be insulated. And it is possible to ensure the tightness of the joints between them during the installation process.
The seams between the rings are sealed with a bentonite-rubber cord of a certain thickness, depending on the width of their walls. During the installation process, distortions must be avoided, they can make all the effort spent in vain.
When insulating from the outside, the joints can be filled with a rubber-bitumen mixture and glued with roofing material cut into strips. From the inside, on the joints, first you need to apply the repair mixture, then glue a special impermeable tape in a circle and coat the seams 2 times with Aquamat-Elastic.
How to waterproof a well - watch the video:
After completing all these procedures, it can be confidently asserted that the waterproofing of the well made of concrete rings has been successfully completed.
