When it comes to modern roof insulation, you often hear about PIR and PUR panels. PUR is a polyurethane that was used to make sandwich panels until recently. PIR is a polyisocyanurate that is slowly replacing it. Although the two materials are similar in many respects, they differ in one important feature. What is worth knowing about both materials?
The power of PIR
PIR and PUR have a similar chemical composition. Both are made of isocujanate, polyol and special stabilizers and activators. It is the large amount of isocyanate that makes a given foam a PIR foam.
Fire retardant properties
PIR and PUR panels have different fire protection properties. In the case of PIR, the breakdown of the chemical chains takes place at a temperature of 300oC. As for PUR, it is only 200oC. This means that in the event of a fire, PIR plates give the user a little more time to react and fight fire, and in extreme cases - to evacuate. But that's not all. A charred coating forms on the PIR plate, which further delays the fire from spreading further. In the event of a fire, the PIR board retains its structural properties longer, so it is much safer, especially when used in the roof structure. PUR usually receives a fire resistance class equal to EI 15, and PIR - EI 30. It is mainly for this reason that PIR boards began to replace PUR boards.
Insulation of materials
PIR and PUR foam is undoubtedly the most energy-saving solution on the market. PIR thermal insulation is characterized by a low thermal conductivity coefficient of λD = 0.022 W / mK, with the use of a relatively thin insulation layer. Modern PIR foams therefore replace polystyrene and mineral wool.
Although PIR and PUR panels are light and easy to install, both are highly resistant to mechanical damage. This makes them great protection against birds or martens, as well as against moisture, mold and bacteria. Due to the relatively low weight, they are also convenient to transport.