Insulating a well for the winter with your own hands: a review of the best materials and methods of insulation

Freezing of a well is a very unpleasant event for residents of country houses who use well water for water supply all year round. It’s quite simple to avoid this - insulate the well yourself. And for a positive result, you need to know the specifics of performing thermal insulation and understand the materials. Do you agree?

We will tell you how to choose the right insulation for thermal insulation of a well shaft. Here you will learn everything about the methods and nuances of carrying out work. Taking into account our recommendations, you can ideally protect your water source from low temperatures.

Reasons for freezing wells

Will the well freeze in winter? This can be predicted with a high degree of probability.

Firstly, if natural wood was used to construct the well, then it will not freeze even with prolonged exposure to sub-zero temperatures. Our ancestors took advantage of this property by constructing wells from wood.

Modern wells are built using reinforced concrete rings, and given that this material has high thermal conductivity, the well will freeze in the same way as the surrounding soil.

Secondly, you need to pay attention to the water level: if it does not exceed 1.1-2.2 m, then the risk of freezing is very high.If the well is deep and the water in it is below the freezing level of the soil, then the water does not freeze.

The third factor that must be taken into account is the depth of soil freezing in the region. In the southern regions, the freezing depth rarely exceeds 0.5 m, in temperate regions - 1-1.5 m, in the northern regions - below 1.5 m.

Thus, the question of how to properly insulate a well for the winter faces owners of reinforced concrete wells located in temperate and northern climates. For residents of the southern regions it is less relevant. There are enough minimal measures - the construction of an insulated cover, and the well itself does not need thermal insulation.

Freezing of a well made of reinforced concrete rings can be prevented by making high-quality insulation, allowing uninterrupted use of water from it all year round

Why is freezing of wells dangerous?

It is a mistake to think that well insulation is only necessary when it is used year-round. Many summer residents and seasonal residents of country houses sincerely do not understand why insulate a well that no one uses in winter anyway. Meanwhile, such seasonal wells also need effective thermal insulation!

Otherwise, a variety of problems may arise that make the operation of the well difficult or completely impossible:

• the formation of an ice plug in the water supply system;
• displacement of the rings resulting from the expansion of frozen water in the surrounding soils;
• failure of the ice plug and damage to pumping equipment;
• divergence of the joints of reinforced concrete rings when water gets between the seams.

Wells that are not protected from low temperatures require repair work much more often.And in terms of financial costs, repair measures are often more significant than carrying out one-time insulation work.

If a water supply system based on a well is installed in a suburban area, then in addition to the mine itself, it is required insulate pipes to protect the system supply line from low temperatures.

Materials and production technology

It is necessary to take care of the insulation of a reinforced concrete well at the stage of its construction.

In this case, you will immediately receive a source of water supply that you can use all year round and that will not require expensive repairs. Thermal insulation during the construction process will cost you much less, and the volume of excavation work will be less.

If a well that has already been built and is in operation needs insulation, then fairly large-scale excavation work is necessary - digging a trench around the well shaft to attach the insulation. Installation of insulation should be carried out 0.5-1 m below the soil freezing level.

Insulation of an existing well to reduce costs and reduce the volume of excavation work is recommended to be carried out in conjunction with insulation of the water supply system

Let's look at what thermal insulation materials can be used for wells built from reinforced concrete rings.

Insulation #1 - polystyrene foam

Foam plastic is a synthetic polymer thermal insulation used for insulation of reinforced concrete wells, both under construction and already in operation.

The advantages of polystyrene foam include:

• high thermal conductivity;
• low degree of water absorption;
• resistance to deformation;
• ease of use;
• low cost compared to other insulation materials.

One of the main advantages of polystyrene foam is that it is produced in the form of round and semicircular elements ready for installation of an insulation system, the diameter of which exactly matches the dimensions of reinforced concrete well rings.

This greatly simplifies the insulation process, which is carried out using the following technology:

1. Preparing the walls of the well for attaching insulation. Preparation involves cleaning the surface from debris, soil and other contaminants.
2. Installation of thermal insulation (rings, half-rings or individual insulation boards) using glue applied to them for facade work.
3. Strengthening the fastening of foam rings with special dowel nails for concrete. Performed when necessary.
4. Installation of a vapor barrier layer. Any vapor barrier material is suitable here.
5. Filling the trench around the well with soil, compacting it and compacting it.

As you can see, there is nothing complicated in the technology of insulation work using polystyrene foam. However, it is worth noting that in addition to the advantages, the described thermal insulation also has some disadvantages.

Such rings must be attached to the walls of the well as tightly as possible, preventing the formation of gaps in which condensate will accumulate in the future, destroying the insulation layer

Polystyrene foam is not resistant to insects and rodents, and low-quality samples can, when heated in hot weather, release toxic substances into the environment - styrene, which poison the soil and top layers of soil.

Insulation #2 - extruded polystyrene foam

This insulation is similar in properties to foam plastic, but has some differences: slightly lower thermal conductivity, higher resistance to low temperatures and aggressive environments. The material can easily withstand loads, so it is widely used in the construction of underground pipelines.

For thermal insulation of a well, you can use extruded polystyrene foam of the following brands: Technoplex, Tenziplex, which is actively in demand in construction Penoplex, URSA made in Russia.

Imported analogues will be identical in properties and quality to Russian ones, but at a much higher cost. By the way, in terms of price, thermal insulation based on extruded polystyrene foam is 20-30% more expensive than foam insulation.

Polystyrene foam insulation is produced in the form of slabs of various sizes. For wells, it is recommended to use slabs with a minimum transverse size of 30 cm, which can be laid as accurately as possible in a circle according to the shape of the well. The technology for constructing an insulation system is exactly the same as for thermal insulation with foam plastic.

The resulting joints must be sealed with mounting foam for exterior use. To ensure a tight fit and additional protection from the effects of groundwater, the insulation installed on the reinforced concrete rings is wrapped with rolled waterproofing material.

The advantages of using extruded polystyrene foam include:

• does not deform under the influence of loads (soil layer);
• resistance to mold and corrosion;
• durability, retains thermal insulation properties for more than 25 years.

When insulating the outer part of a well located above the ground, it is advisable to secure the insulation with special metal brackets to prevent it from moving.

The following photo selection will present the process of insulating a well shaft step by step:

Insulation #3 - cellular polymer materials

Materials belonging to the group of closed-cell polymer-based insulation have found the widest application in construction.Due to their properties: high thermal insulation characteristics, resistance to moisture, plasticity, these heat insulators are increasingly used for insulation of reinforced concrete wells.

One type of polymer insulation with a cellular base is isolon. Its analogues are also presented on the construction market: planex, isonel, tillite, penolin, etc. These materials are produced in the form of rolls, which makes it possible to easily insulate round reinforced concrete wells.

Most materials in this group are self-adhesive, i.e. do not require additional fastening to reinforced concrete walls.

The insulation technology with isolon or its analogues is as follows:

1. Preparing the surface of the outer walls of the well.
2. Treatment of reinforced concrete rings with a special primer that increases the adhesion of concrete and insulation.
3. Gluing isolon using glue for exterior use (if the material is not self-adhesive).
4. Sealing joints with adhesive tape.
5. Backfilling the trench and compacting the soil.

The group of mineral-based cellular insulation materials includes foam glass, produced by foaming silicate chips under special conditions. This insulation has good thermal insulation, is environmentally friendly, and is easy to use, but its too high cost does not allow it to be used for thermal insulation of wells.

To reduce the cost of insulation with isolon, it is recommended to use non-foil material - its cost is much lower, and the additional properties that foil provides are not important in this case

Insulation #4 - polyurethane foam

Polyurethane foam is an insulation material with unique properties: high thermal insulation, resistance to humidity and aggressive environments, it is not susceptible to insects. The service life of polyurethane is at least 50 years!

Today, manufacturers offer two types of polyurethane foam insulation: ready-to-use, sold in special containers, and in the form of a dry mixture that requires dilution before use. Polyurethane foam is applied to the surface using special spray equipment.

The technology for creating an insulation system is as follows:

1. Surface preparation and treatment with a primer.
2. Dilution of the polyurethane foam mixture in accordance with the manufacturer's instructions.
3. Application of polyurethane insulation using a special sprayer.
4. Painting the above-ground part of the well with paint for exterior use.

Polyurethane foam has optimal thermal insulation properties, and the spray application method allows you to create a durable layer of thermal insulation without seams or joints. The applied composition hardens within a few minutes, and final hardening occurs after 4-5 hours.

The disadvantage of this method is the high cost of the material; polyurethane foam is one of the most expensive insulation materials, as well as the need to use special spray equipment. Another drawback is that it is necessary to apply insulation only in the temperature range from +15 to +30 degrees.

Polyurethane foam is not only an excellent heat insulator, but also reliably fills all the cracks and cracks formed on the outer walls of the well

Why can't you use mineral wool?

Many people wonder how best to insulate winter water supply well using such a popular insulation as mineral wool. The answer to this is simple: it is absolutely forbidden to insulate a well with mineral wool!

Well insulation made using mineral wool will not last long, and after a few years you will find that the well will begin to freeze

Having good thermal insulation properties and a low price, this insulation, however, has an important significant drawback, which makes its use for thermal insulation of wells impossible.

We are talking about the ability of a material to absorb water from the environment. Therefore, mineral wool is a “leading” parameter; it quickly absorbs moisture, while losing its thermal insulation qualities.

Well cover and wooden house

To ensure the best protection of the well from freezing, in addition to insulating the well shaft, it is also necessary to carry out external insulation work. They consist of constructing and insulating the well cover and/or erecting a wooden house over the well.

The well cover must be installed taking into account the maximum water level. The movement of the cover is ensured by a cable or rope. The best material for making a lid is wood. Also an excellent option would be a three-layer cover made of two layers of thick plywood with insulation between them.

It is advisable to use polystyrene foam or polystyrene foam as insulation.

If you decide to use a well cover made of reinforced concrete, then it also needs to be insulated by attaching a layer of foam plastic or other insulation. Fastening is carried out using glue for external use and dowel-nails for concrete.

To ensure that the wooden lid lasts a long time and does not swell from water, it is recommended to treat it with a waterproof composition for wood.

Installing a house over a well is a more expensive method, however, it has its advantages:

• reliable shelter of the well shaft from debris and precipitation;
• the ability to use the well in any weather (rain, strong wind);
• aesthetic appearance, a wooden house is perceived as an element of landscape design.

You can make such a wooden house yourself or buy a ready-made version. In any case, it is worth knowing that the house is not simply installed on the surface of the ground. It requires a foundation, which is done as follows: the area around the well is leveled and a blind area is made, on which a layer of fine crushed stone is poured or tiles are laid.

After this, a wooden house is mounted, and the space between it and the reinforced concrete ring is filled with insulation. In this case, expanded clay, an inexpensive bulk material, can be used as insulation.

Conclusions and useful video on the topic

Video #1. Insulation of a well with foil isolon:

Video #2. Creating thermal insulation by spraying polyurethane foam:

In our climate, insulating a reinforced concrete well is a necessary measure, even if it is used seasonally. The costs of carrying out insulation work will pay off in the shortest possible time, because you will no longer have to carry out expensive repairs to the well and organize the supply of water when it is not working properly.

The choice of thermal insulation materials on the modern market is large and you will certainly find the option that best suits your installation method and cost.

Would you like to talk about your own experience in insulating a well shaft or provide useful information? Perhaps you have any questions while reading the information provided? Please write comments in the block below.