Insulation Of The Foundation From The Inside In A Wooden House: How To Use Expanded Clay For The Floor, How To Insulate The Basement Inside The Building

2024 Author: Beatrice Philips | [email protected]. Last modified: 2024-01-15 04:10

In a wooden house, the insulation of the foundation is usually carried out outside, since this method allows you to protect the foundation itself from freezing in winter. At the same time, in some cases, external insulation turns out to be insufficiently effective, or even completely impossible for one reason or another, therefore, it is necessary to use insulation inside as well. It should be noted that the decision to insulate the basement of a private house from the inside will help protect the floor structure from freezing and increase the degree in the basement, but it will not be able to protect the basement itself. However, if this is an additional or no alternative measure, then there is no choice.

Methods of internal insulation of the basement are varied, and some of them are even part of the interior decoration in parallel, but it is always worth starting with reliable waterproofing of the foundation.

If it is not possible to externally protect the concrete from freezing, you need to protect it at least from the penetration of water - for example, using penetrating insulation. Being dry, the foundation will not freeze so much, which means that the lack of external insulation will not become a critical drawback.

Insulation types

Internal insulation by materials is not so different from external insulation. As a rule, one of three basic materials is chosen.

Fill the basement with expanded clay - the cheapest and easiest of all solutions. With the help of such insulation, it will be possible to reduce the effect of cold on the flooring due to the air cushion created and to drain excess water. As a rule, the entire room under the floor is covered with expanded clay, so any other purpose of the basement becomes impossible. Alternatively, you can fill only the formwork specially installed on the inner side of the basement walls with expanded clay, but then the level of heat saving will greatly decrease. Expanded clay, in principle, cannot be called the most reliable insulation, therefore, in capital buildings it is almost never used, being limited to use in summer cottages and in summer houses.

Internal insulation with expanded polystyrene, polystyrene or polystyrene foam , as well as other board materials have recently become more and more popular. This solution is perfect for basements that are planned to be used as a living or storage space, since any other finish can be easily applied on top of the slabs, and they themselves take up very little space. In the described situation, external and internal insulation is usually combined, since this way it is possible to avoid condensation of moisture under the insulation. If there is no external insulation, you should take care of the complete removal of moisture and steam, since these materials do not allow them to pass through. To do this, you need to impregnate the foundation with penetrating waterproofing, and organize double-sided ventilation inside the room.

Polyurethane foam insulation is still relatively rare, since it is quite expensive and requires the obligatory involvement of specialists and special equipment. In terms of its advantages, the result resembles the one described above with the difference that, unlike boards, polyurethane foam is poured using a seamless method. This significantly improves the degree of insulation and almost completely eliminates the disadvantages of the plates, therefore this choice is considered universal.

What should you pay attention to?

When choosing a specific material, you need to start not only from its positive qualities and your own financial capabilities, but also from the specifics of the structure that you plan to insulate. The wrong choice of insulation can negatively affect the atmosphere of the basement, not give a noticeable result, or require unforeseen additional costs. In order not to be mistaken, you should pay attention to a number of parameters of the house.

• The structure of the building plays an almost decisive role in the choice of insulation. If the basement is small, with low ceilings, and at the same time it is not particularly used in any way, you can fill it with expanded clay, especially if no one lives in the house in winter, or external insulation is also present. It is a pity to fill a spacious basement with expanded clay, and quite expensive, therefore it is worth considering other heaters.
• The presence of external insulation and a relatively mild climate allow the owner of the house to freely choose any insulation he likes for the inner part of the foundation, and if the basement is not insulated from the outside, and even the climate is rather harsh, it is worth insulating the basement at least with slabs.

If the groundwater on the site is abundant and located quite close to the surface, this may be the reason for choosing expanded clay. The fact is that plastic heaters, although they do not allow water to pass through, when moisture disappears into the gaps between the wall and the heater itself, they significantly reduce their service life. The problem can be solved with the help of penetrating waterproofing for the walls - although this is an additional cost, but the basement will be more intact, and it will be possible to use plates for insulation

Depending on how serious the owner wants to see the insulation, you should choose from the "coldest" expanded clay through the "medium" plates to really warm polyurethane foam. In the case of expanded clay, the reliability of thermal insulation strongly depends on the thickness of the layer used - laid along the walls in reinforcement, it will not give a tremendous effect. If there is heating in the basement, then it can not be insulated as much as if it was not there

• The lack of ventilation and the impossibility of arranging it almost completely limit the owners in insulating the foundation with expanded clay alone. If there is no ventilation, but you still want to see the plates or polyurethane, you will have to think about where the moisture from inside the room will go. If everything is in order with the ventilation in the basement, then any restrictions on the choice of material are removed.
• If the basement is to have a practical application and look beautiful, it is worth giving preference to slabs and polyurethane foam covering, on top of which almost any finish can be installed. It is quite difficult to hide expanded clay, because it will almost certainly determine the look of the insulated basement.

Backfill with expanded clay

This method is very cheap, but relatively ineffective, therefore it is massively used in summer cottages. You can also fill it yourself, for which a number of actions are performed.

You should know that the entire basement is not always filled up with expanded clay . - along its perimeter at a distance of at least 0.3 meters from the inner walls, you can make a wooden formwork to the full height of the room, behind which expanded clay will be filled. However, given the small size of the country houses, they often do not make formwork, simply filling the entire space of the basement with pebbles.

If the formwork is being done, it must be treated with a special antiseptic, after which you can even try to finish the surface.

The bottom of the space between the formwork and the walls is lined with a polyethylene film, the task of which is to prevent moisture from passing from the soil to expanded clay, which would quickly absorb it. Respectively, if the basement is covered with expanded clay over the entire area, waterproofing is also laid over the entire area . Expanded clay itself is poured on top of it, the layer of which in height must correspond to the height of the formwork, that is, reach the ceiling of the basement.

Given the relatively low thermal insulation of expanded clay, many owners use additional thermal insulation for the floor from the basement side. For such purposes, mineral wool and a special membrane of a vapor-waterproofing type are used. Both materials are placed between the sex lags.

Pasting with plates

The material from which modern plates for insulation are made can be called differently - polystyrene, polystyrene, penoplex, but, in fact, all these are types of plastic that have approximately similar properties with slight differences. Such differences are due to both differences in composition and the brand of the manufacturer or the density and thickness of the board.

It is generally accepted that the internal insulation of the basement and foundation is fully achieved thanks to the plates, whose thickness is 5-10 cm.

Since the boards are glued to a flat surface, serious wall preparation is required. The inner surface of the foundation is leveled, any chips and cracks are carefully repaired. After that, the walls of the basement are insulated from moisture penetration - the best and most reliable method, as already mentioned, is penetrating waterproofing.

The slabs are attached to the walls with a special glue, which can be sold either as a powder or as a ready-made solution . If you purchased a powder, you must first prepare the glue, following the instructions on the package. Not the entire surface of the slab is coated with glue - it is enough to apply it pointwise, but in an amount of at least 6 points. After that, the slab is firmly pressed into the wall and held in this position for some time.

Often, for ease of installation, slabs also have grooves - they must be combined in order to achieve maximum reliability of thermal insulation. To increase the effect, laying in several layers can be used - in this case, the plates are laid in a checkerboard pattern to reduce the load on the glue.

Insulation can weigh quite a lot, so you should not rely on glue alone. After it dries, holes are made in the insulation 5-6 cm deep more than the thickness of the material - so that the hole goes deep into the foundation. After that, plastic dowels are driven into the holes, additionally fixed with special nails. In this case, the fasteners should not stick out, being flush with the surface of the insulation.

The work does not end there, since polystyrene and its analogs are of interest to rodents and are susceptible to their effects. To protect against rats and mice, a special reinforcing mesh is applied over the insulation, held in place with cement glue.

After that, plaster is applied to the grill, and any finishing can be done on top of it.

Polyurethane foam spraying

This method is highly appreciated by consumers not only for its high heat-saving qualities, but also for the fact that it does not require any additional work. No wall preparation is required - high pressure foam is sprayed on the surface of any relief, itself being a leveling factor. The procedure does not take much time, and most importantly, the resulting surface also does not need to be prepared in any way - the finish can be applied immediately, directly over the polyurethane.

Due to the complete absence of joints and seams, such insulation can be used for a very long time. Given the high not only insulating, but also water-repelling qualities of polyurethane foam, it is actively used to insulate not only basements, but also any other premises.

The only drawbacks are the need to use a special spray installation, which must be ordered somewhere, and the high cost of such a heater. Nevertheless, reviews indicate that the high cost of polyurethane foam insulation fully justifies itself.