Recommendation points
- What are the goals of insulation systems
- Such different installation conditions
- Moisture saturation problem
- Durability and versatility
- Financial side
With the correct execution of the insulation belt, heating costs in the cold season are almost halved, and the service life of the house increases by the same amount. Today we will analyze the main insulation systems with all their advantages and vulnerabilities, we will name the most popular materials and point out the pitfalls.
What are the goals of insulation systems
Do you know what is the main principle of insulating any building? Ideally, this is the creation of a continuous shell of material that well prevents heat transfer. Unfortunately, such an idyllic view is almost impossible to implement in practice, and there are several reasons for this..
Thermal imaging studies clearly show the “weak” spots in the thermal insulation of the building, cold bridges
The first of them is the heterogeneity of the layer in the frontal secant projection, caused by the so-called cold bridges. This is a real scourge of almost every home insulation system: in such zones, nothing prevents the outflow of heat, respectively, inside the house, sufficiently large sections of the walls will remain cold. A really continuous contour at the moment can be made either with foam glass blocks, or by gunning from the base to the ridge.
There is another danger in the presence of cold bridges. In most design calculations, point leaks are not taken into account, but you need to reliably know how heat is distributed inside the insulating “pie”. Cold bridges make the belt non-uniform, and the main temperature boundaries shift accordingly. Such miscalculations are most often expressed in the formation of condensation in unforeseen and, as a rule, the most vulnerable places. And this is the second scourge of any insulation system – most readily available materials do not tolerate getting wet and the following negative temperature.
Frosty swelling, an abundance of moisture in the pad is a common reason why building thermal insulation becomes useless
The phenomena described above should be avoided at all costs, otherwise the invested funds will definitely be thrown to the wind – not in five years, so in ten. At the same time, there are a number of other phenomena that must be taken into account: the blowing rate of the cake and walls, the height of the snow cover, and local insolation. But high-quality design work must be supported by equally good editing..
Such different installation conditions
There are enough videos on the Internet in which the wind, like a sheet of paper, tears off the protective cover, exposing the wall of a multi-storey building. Of course, this is an extreme degree of negligence and the result of terrible financing of contractors, but after all, incidents happen in private development. The problem of fixing the insulation and the cladding layer is the more acute, the more exotic the material of the enclosing structure and the thicker the insulation layer.
This problem does not stand as such when working with brick and panel houses, with a wooden frame. In the case of insulated panels and frame construction, any difficulties are completely excluded. However, most common materials, such as foam block, cinder block, shell rock, slag casting and other loose structures, pose a serious threat of subsequent destruction..
If in the classical case installation on a concrete base can be performed with ordinary “umbrellas”, then for non-solid walls either preliminary preparation or the use of special types of chemical fasteners is needed. Embedded reinforcement elements installed as masonry, on which the frame base of the future cake can be fixed, help well. If there are none, the wall should be plastered over a galvanized or plastic mesh with a layer of 45-60 mm.
This complicates the finishing for the insulation of multi-storey buildings, because the fastening system must restrain the resulting windage and the own weight of the finishing layer.
Moisture saturation problem
In the light of all of the above, there will be no complaints except for the systems of ventilated facades. The fastening in them is spaced pointwise, which allows you to fasten the brackets to the wall with two long screws or pins. At the same time, enough space remains in the cavities of the frame to accommodate an impressive thickness of the insulation layer, and heat loss through the technological fastening elements is minimal.
The main advantage of such a finish lies in the name: all the insulation is at the outside temperature and, even if moisture forms in it, it immediately evaporates with the incoming dry air and does not have time to accumulate and precipitate with water.
There is another way to prevent getting wet, by cutting off the moist air seeping from the inside of the building. All kinds of woven synthetic fabrics allow you to choose the optimal degree of localization of water vapor, provided for by the insulation project.
Vapor barrier materials help maintain the gradient of the vapor transmission capacity of the entire “wall cake”
This approach also has disadvantages: it is necessary to prepare the basis for fixing the membrane, carefully glue the latter, and open contact of the insulation with the external environment is completely excluded. Active air currents, especially wind gusts, reduce the density of the insulation, inflating it. Steam insulation is necessary in almost any project, but it should always be located only on the warm side and be extremely tight, at least on certain surfaces.
Durability and versatility
Perhaps there is another way to avoid the negative effects of moisture? Indeed, if the material used has minimal water absorption, then structural defrosting is not scary. There are three optimal options for a private developer.
The most common now is expanded polystyrene. It should not be confused with foam, which consists of glued round balls, while EPS has a homogeneous structure with micropores. Most foams can absorb enough water to form a free-flowing mass over time. Add toxicity and flammability to this – foam is not the most profitable material for wall insulation.
Of the newest materials, foam glass is interesting. This is the absolute leader among the means of insulation: the lowest known thermal conductivity, ease of processing, complete absence of cold bridges, proven complex technology. But there is also a fly in the ointment, even three:
- High price
- Low availability for the average consumer
- Correct installation is critical
The golden mean will be polyurethane foam. Its resistance to heat transfer is only slightly lower, but it is found on construction bases everywhere and in sufficient quantities. The ease of installation and the different format of the insulation material will be pleasant additions to this. PU foam can be supplied in slabs and in structural insulation, in bulk or applied by a gunning machine.
All three materials have another interesting property: their laying in the outer layer helps to localize insulation from moisture, which is less resistant to wetting. And in general, insulation with dissimilar layers is always preferable to homogeneous.
Financial side
At the end of our review, we will point out the last, but not in importance, argument – the economic feasibility of insulation measures. First of all, in planning such work, you need to proceed from the payback period: how much the costs will be covered by the savings on fuel consumption at its current price and the temperature regime of interest. There is almost always a benefit to bypass the building with an insulating belt without insulation, at least two “cold” walls of the house need it. But building insulation requires a strictly individual approach..
