The very common application of mastic between the window frame and the cill is not the best idea. No installer can guarantee that the right quantity of mastic will end in the right position, to achieve a proper sealing of the joint. In the most cases, the result is more or less as shown in the second photo, where the mastic oozes out underneath the drip.
The Gap Filling Foam Tape for window cills was especially made to seal the joint between the cill and the window frame permanently. It has a width of 30mm to ensure the best water tightness and insulation. The Gap filling Foam Tape expands automatically after installation, to close the tiniest gaps completely. The self-adhesive side of the tape can be easily applied to all types of window frames.
This tape is approved for joints between 4mm and 10mm.If you want to cover a wider gap properly, please get in contact with us.
This Gap Filling Foam Tape has a 10 year performance guarantee.
Water Tightness: up to 750 Pa
Air Tightness: a ≤ 1.0 m³/h/m²
Fire behaviour: B1 / DIN 4102
sd Value: 3
Dimension: 4 (-10mm) x 30mm x 12m
Temperature resistance: - 20°C to +80°C
Please notice that the tape should be sticked to the window frame before adjusting the frame to the cill.