Choosing the correct seal

As important as renewing the seals periodically is choosing the correct seal for the windows and doors. If your previous weatherstrip has worked well, you should usually choose a similar seal to replace it. There are various types of seals out there; e.g. groove seals, self-adhesive seals and silicone seals. O-profile (omega) groove seals are placed into grooves in your door/window. In most new windows this groove is already in the door/window. For older doors and windows we recommend you to use self-adhesive seals or to contact a professional in case you'd like to switch to groove seals. We recommend that you don't make the grooves yourself.

Measuring the gap

You can measure the gap with e.g. blue tack. You should measure both inner and outer window separately. Place the blue tack in place of the seal and close the window / door. Measure the width of the flattened blue tack and choose a seal that's 2-3 mm thicker than the measurement.


1 - 2 mm
2 - 3 mm
3 - 4 mm
4 - 6 mm

Width of the seal (mm)

3,5 - 4,0
4,0 - 5,0
6,0 - 7,0
7,0 - 10,0