Shopping cart

Your cart is currently empty.

Total price:  0 €

Go to checkout

How to choose a suitable PU foam for window installation?


One of the most complicated and demanding joints in construction is considered to be the window installation joint. Wrongly installed windows and doors can cause heat loss and increase a building’s energy consumption. Correctly installed PU foams are an essential part of the window installation process as they help to improve a building’s energy efficiency by minimising thermal bridges and heat losses and improving airtightness.

When choosing a PU foam for window or door installation it is important to pay attention to the following characteristics:

Thermal insulation:

  • The lower the PU foam’s thermal conductivity value, the better its insulating capacity.
  • Our Window & Door category PU foams have a thermal conductivity value of λ=0.033 W/(m·K), in comparison glass mineral wool has a thermal conductivity value of λ=0.044 W/(m·K).


  • During the building’s life cycle, window and door joints will be exposed to structural expansions and contractions due to temperature fluctuations.
  • All PU foams in our Window & Door category are elastic and can move with the structure without losing the bond.

Sound insulation:

  • During window installation, on top of airtightness, elasticity and thermal insulation value, it is also important to pay attention to the PU foam’s sound insulation value. The higher the sound insulation value, the more soundproof the structure is.
  • Penosil Window & Door category PU foams have a sound-reduction index of 63 dB.

Curing pressure:

  • For fragile and pressure-sensitive construction works such as window and door installation, it is important to choose a PU foam with a low curing pressure.
  • All Penosil Window & Door category PU foams have a very low curing pressure, which means that the foam only expands into the available space, and it will not warp or bend the sealed materials.


  • Air leakages account for about 25% to 40% of heat loss in a cold climate and 10% to 15% of heat gain in a hot climate.
  • Our Window & Door category PU foams ensure window joints’ airtightness and help to prevent a structure’s air leakages and humidity problems and increase its fire safety.


  • To ensure a safer user experience and to guarantee better air quality, it is important for window installation to use PU foams that are low-VOC certified.
  • All Penosil Window & Door Category foams are EC1+, French A+ and M1 certified.

Usage temperature:

To ensure window joints’ airtightness, it is also recommended to use a range of other products such as membranes, tapes and silicones during the window installation process. If all these products are used together and in the correct sequence, they guarantee a building’s energy efficiency, aesthetic appeal and cost efficiency. To find out more about how to apply PU foam correctly and which other products to use for window installation, visit our Energy-efficient window installation solutions on