1. What is PUR and polyurethane foam and what is it used for?
Polyurethanes (PUR or PU) are the polymers resulting from addition polymerization of multifunctional isocyanates into amines and alcohols. Our Polyurethane Foam is a two-component liquid applied by the spray unit under the pressure of 140 bar; it is used as a modern insulating and sealing technology demonstrating excellent phono-insulating properties (open-cell foam) and hydro-insulation properties (closed-cell foam).
2. Is this a new technology and is the invariability of the parameters guaranteed?
The technology used for foam spraying is generally relatively new in Poland. In contrast, it has been used for decades worldwide, and it is well suited in insulation of the lightweight wood-frame houses, passive houses based on steel structure, as well as traditional houses built in Poland. The foam has been tested and proven in the accelerated aging chamber and has a certificate of the invariability of the parameters for 25 years guaranteed by the manufacturer (global corporations producing polyol).
3. Is the foam flammable?
There are various foams produced by different manufacturers. The foam offered by us is the flame-retardant foam - Fire classification of construction products and building elements PN-EN 13501-E Flammability as per DIN 4102 Class B2.
4. Is the foam safe for health?
Of course, aside from the spray process itself where solvents and hardeners are used, after 24 hours the foam is no longer hazardous to health and after a good airing and seven days it is completely odourless and safe for humans, which is certified by the Polish Hygienic Society, which allows its use also in the industrial houses where the food is produced.
5. Does the foam cause allergies?
No. In contrast to other insulating materials which contain on the label the information on the safety measures directly during its application and the structure is hard to clean; therefore, various types of mites and dust can accumulate. The structure of the foam is closed, which hinders the deposition of dust and does not cause irritation of the upper respiratory tract, and thus it does not lead to allergies - the foam is ideal for persons suffering from allergies!!! (Although it should be stressed that no insulating material itself does not cause allergies).
6. Will the structural steel coated by the foam not corrode?
On the contrary, the foam (in a way) insulates the steel surfaces. It is used in passive houses with a steel structure.
7. Will the wood contained in the foam not rot or decay?
The foam is applied onto the already seasoned wood. Additionally, the open-cell foam to a greater extent and the closed-cell foam to a less extent are breathable materials, so no need to worry about the risk of rot and decay. The foam has long been used for the insulation of lightweight framed houses.
8. What are the types of the foam?
Basically, due to its structure, the foam can be divided into the open-cell foam and closed-cell foam. The first is fully breathable and water absorbing, while the latter has a closed structure and is waterproof. Additionally, the foam can also be divided into hard, medium and soft. Each of them has a different use, depending on whether it is to be poured onto the floor or sprayed onto the wall.
9. Is the foam breathable?
The open-cell foam is a better breathable material, while the closed-cell foam is less breathable, but both are breathable, which is proven by tests.
10. What foam should I choose?
Depending on the work you are planning to do, you should choose the foam that is suitable for the intended use. In this case our advisor will assist you with this selection, but overall for external insulation and moisture-prone areas you should use the closed-cell foam, for attic boards – the open-cell foam and on walls – the lower density foam, while on hard floors – the higher density foam.
11. How to choose the right thickness of the foam and what is the formula for this?
How to choose the right thickness of the foam and what is the formula for this? The attic energy efficiency is specified by the Polish standard that required adapting to the EU Directive and it shall remain in force until 2017, after which it will become even more rigorous. That standard regulates the specifications of products without specifying the layer thickness – it is apparent from the calculations. In 2014, the Polish standard indicated the U = 0.2 for attics and ceilings. In the case of our foam, this corresponds to the 17 cm open-cell foam, or the 10 cm closed-cell foam. However, please remember that contrary to appearances, the tree is not a good insulator, so the rafters should be covered in winter, as they can freeze. Therefore, the optimal solution is the 20 cm thick foam, which corresponds to approx. 35 cm thick wool. U= lambda / foam thickness
12. In my building design, why is there no specific thickness of the insulating material or why is the thickness too small?
Especially in older designs, there was no obligation to indicate the thickness of insulation of attics and often the value of this layer thickness was too small. This results from a minor error, because designers applied the lambda coefficient, which in the most insulating materials is calculated for the section (e.g. having a size of 10x10 cm). In contrast to the foam where our parameters are given for the partition wall and the section and because of the overall spraying, these parameters are equal.
Formula: U - heat transfer coefficient [W/m2K]Lambda - thermal conductivity coefficient [W/mK]The thickness of the layer of insulation in cm
For example, the open-cell foam lambda is 0,034 and it is calculated for a thickness of 17cm, i.e. 0.17 m
U=lambda / partition wall thickness, in this case 17 cm foam
U=0,2[W/m2K]However, bear in mind that the most effective will be the insulation covering wood the – rafters.
13. What is a partition?
The partition is part of the building that separates its interior from the external environment or separates individual rooms, for example a wall, ceiling, lattice.
14. Is the foam profitable?
It is natural that the conscious customers will choose the foam, because by using it they will reduce their home heating costs (gas, coal or other energy carrier), which is estimated at 30% to 50% compared to insulating the attic by other conventional methods. Given that the heating season in Poland lasts up to six months, the differences in costs resulting from the use of the foam should be returned after the first heating season. This can be compared to car maintenance: a cheap car is not always the cheapest, but the one whose maintenance is the cheapest. Therefore, you shouldn’t always choose the cheapest solution because this is a short-sighted approach.
15. What they are thermal bridges and how they can be noticed in home conditions?
Thermal bridges (some refer to them as cold bridges, which may not be the same and correct) are the areas of the wall, floor or roof, where due to poorer heat insulation properties the heat tends to escape. This is the result of the use of the improper technology, poor adhesion of one material to another, e.g. between the rafters and the traditional insulating material or as a result of sagging. Flexible insulating materials also tend to slide down the inclined plane. It is estimated that with the insulation on the 200 sq. m roof, an opening the size of the 2 m x 2 m window is created in the roof due to thermal bridges. This shows the weakness and inefficiency of this type of method.
The easiest way you can observe the "thermal bridge effect" is by leaving a small gap in the window in winter and then you can see how the air gets pushed inside at high pressure and you can feel the chill in the whole house, the same thing happens when there is no perfect adhesion between the insulating material and the rafter, but because of the plasterboards it is difficult to feel it directly, but sometimes the frozen rafters show black vertical stripes on the plasterboard ceilings, which is the visible evidence of the leaks.
16. Is there a condensation effect and is the membrane required?
The condensation effect is due to the temperature difference between the inner and outer surfaces and over 5 cm of foam this effect is no longer present, and there is no need to apply the vapour barrier film onto the foam, but there are no contraindications, especially in areas exposed to moisture, such as bathrooms and kitchens.
17. Why is the foam more effective than the insulation used so far?
As shown before in question 15, where thermal bridges have been described, it is because of them and the fact that the foam retains its invariable parameters and does not tend to clump together and slide down; also, a much better lambda parameter gives you a big advantage. To illustrate the effectiveness, imagine an ordinary jar turned into a thermos that consists of small pieces of the best insulation material – it will be very ineffective, but coating the jar with the foam will provide insulation, demonstrating a high effectiveness due to lack of thermal bridges.
18. How long does spraying take?
The 250 sq. m attic takes one working day.
19. Is it possible to spray directly onto the membrane and what foam shall I use?
Yes, by all means it is recommended. If this is the attic, then you should spray the open-cell foam.
20. Is it possible to spray directly on the boarding?
Each time, when our representatives arrive to take the measurements, they measure the humidity of the roof structure using a hygrometer and determine the individual conditions. But the main idea is the humidity level should be <11%.
21. Is it possible to spray directly onto the boards with a roof covered with tar paper and what foam shall I use?
It is quite a unique case and it should be consulted each time, because on the one hand we are dealing with a sealed surface created by roofing paper. On the other hand, we don’t want it to be so closed so tightly because in this case we recommend the application of the open-cell foam and of course the moisture in the roof truss should be measured by our consultant.
22. Is it possible to spray directly onto the sheet metal and what foam should I use?
The sheet metal is sprayed by the closed-cell foam (it must be a warm season with low humidity), the optimum thickness is 10 cm on the ceiling and 8 cm for the walls. This is due to the European directive, where the U coefficient for ceilings is 0.20 and for walls it is 0.25
23. Is dilation with foam spraying required?
Rather not, but there are some exceptions to this rule.
24. Why is the closed-cell foam much more expensive than the open-cell foam?
This is due to a very simple fact, namely, the closed-cell foam has a much higher density, e.g. the open-cell foam is 12 kg m3 and the closed-cell foam is up to 60 kg/m3, therefore much more material is used.
25. How to prepare a room for spraying the foam?
Remove all unnecessary things from the room in order to ensure the unobstructed movement of scaffold or the ladder, and if there are “roof windows”, they should be covered with a board. If you use plasterboards and the beams are to be coated, first screw in the S-shaped brackets or other fixings. (The easiest way to do this is to use dyed twine and make a marking on the rafter to indicate the areas where the brackets are to be screwed in). Our fitters team will do the rest – protecting with the film and cleaning up.
26. Do you fit in the S-shaped brackets?
We are not involved in the fitting of brackets, membranes, meshes and cardboards, but we cooperate with companies that we recommend for this type of work.
27. Will you need the power supply?
Our company is self-sufficient, we don’t need electricity. To energize our equipment and the compressor, we have two high-quality power generating units for electricity and air supply. You will not incur any additional costs related to electricity bills.
28. Does the foam absorb moisture?
The closed-cell foam does not absorb moisture and it is a great insulator.
In contrast, the open-cell foam both absorbs moisture from the air and returns it.
29. How long does it take for the foam to dry?
The two-component foam is sprayed under the pressure of 140 bar. The liquid distributed on the surface swells and dries in just 12 seconds.
30. Is it possible to supplement the already existing wool insulation with an extra layer of foam?
The answer is not simple and the combined solution is more expensive but possible, and dedicated to those of you who have realized how much heat escapes through the attic. In that case, after removing the drywall and isolating the wool layer with the dedicated mesh and extending the brackets for mounting plates, you can spray the foam layer.
31. Can rodents, such as martens, rats, mice create nests in the foam?
In contrast to the traditional insulation, rodents do not nest in the foam – they don’t like this material and have no freedom of movement due to the absence of expansion joints and due to close fitting of the material they feel uncomfortable (not very safe) in it. Therefore, they will not nest there. The foam material does not give the effect of scrapers, like the traditional insulation does, and it is the martens who like to rub against it and stay there, often leaving uninvited guests, because it should be remembered that the rodents – including martens – are carriers of scabies and all sorts of other insects (fleas, lice, etc.), not to mention the animal faeces. It must be emphasized that no animals can penetrate insulation material if everything is tightly closed and performed both compliance with the manufacturer's recommendations regarding the construction and technology. The described point concerns the case where the animals have found unsecured access to the attic.
32. Is it true that it is the ideal solution in low-ceilinged rooms?
This is due to the fact that the 20 cm foam replaces approx. 35 cm of traditional insulation, so it is an ideal solution for low-ceilinged rooms wherever it is not possible (or we simply don’t want) to lower the ceiling room. The foam saves space in the attic!!!
33. Can I see it somewhere?
We have foam samples that we can always deliver to the client, but it is not always possible to demonstrate to the client the work completed in the past. This is due to two facts: some clients don’t like strangers milling around their newly built house. Sometimes we stay in touch with the main investor and in that case we will offer you access, but you should also remember that when it comes particularly to the attic or loft, they are quickly covered by plasterboards (which is right, since the foam is not resistant to UV rays) and in that case nothing can be seen anymore.
34. What shape is the sprayed foam and can you adjust it?
Shaping the foam during spraying is quite limited; the end result usually resembles the structure of the "cauliflower", it can be shaped after spraying, for example, with a knife. Therefore, the foam thickness is averaged, i.e. ± 2 cm
35. Why do we need to sign an agreement?
An agreement is a legal means of safeguarding the interests of both parties; it also gives the consumers the opportunity to take advantage of the reduced VAT rate at 8% (in single family houses with an area of up to 300 sq. m usable area) and thus it is an integral part of the bill or invoice.
36. What is the warranty on the service provided?
After tests of the invariance of the parameters, including oxidation, performed in the accelerated ageing chamber, foam durability has been estimated at 25 years. The warranty for the services rendered correctly by Kadri Sp. z o.o. for individual customers is 2 years.
37. If I use 20 cm foam for attic insulation and I don’t use any warming there, what will be the temperature at home, if it is around 0°C outside?
There is no credible and reliable answer to this question; it depends on many factors: the thickness of the walls and their insulation from the moment when the outside temperature was high, on the accumulation of heat in the walls, etc. Not to mention the windows – even such details as the side the windows are facing have an impact, and this fact is known to all those who have encountered the subject of passive houses, because it all comes down to the amount of sunlight. It is a question that can be answered after performing tests and calculations in academic conditions. These will be estimated laboratory indicators.
38. What are the standards for energy efficiency for houses in the coming years as recommended by the EU?
The standard for the roof and attic now is: U = 0.2, after 2017 – U = 0.17, after 2021 – U = 0.15, i.e. 75% of the current standard for passive houses.
39. Is the foam also used for insulating the foundations?
Yes, the closed-cell foam is an ideal water and heat insulation. Depending on the intended effect, apply the layer and use the appropriate density.
40. Do you provide spraying services outside Poland?
Yes, our company has successfully implemented several projects in Germany and Sweden and single projects in other EU countries. We are always ready to provide our services for foreign investors.