Curtain Walling and Glazing

Sealing Curtain Walling and Window Interfaces

On most glazed facades the weak point is not the glass but the joint around it. The frame and the structure move at different rates, driving rain gets pushed into any gap, and air leaks through anything that isn’t sealed properly. All of that has to be dealt with at the interface between the frame and the wall, so the products in this category focus on that perimeter joint rather than the glazing itself.

What’s in the Range

• SikaHyflex 250 Facade: a one-part, low-modulus sealant for movement joints in concrete, masonry and EIFS facades. It cures with moisture in the air and can be painted over once it has cured.
• Sika Expansion Tape 600: a self-adhesive, impregnated tape that expands to fill the gap between a frame and its opening. Handy where the joint is uneven or too wide to rely on a gun-applied sealant alone.
• Teroson FO 2 FR: a flame-retardant membrane (B-s2, d0) for sealing the connection between window frames and the building structure. It is waterproof, airtight and resists driving rain, but stays vapour permeable (sd value below 1 m) so moisture can still escape from the wall.

Choosing the Right Product

For a visible joint that has to move and take paint, a sealant is usually the answer. For the gap behind a window frame, a tape or membrane gives a more reliable seal and is quicker to fit. On a lot of jobs you’ll end up using both: tape or membrane at the back of the joint, sealant on the face.

Not sure which suits your project? Get in touch with the joint width, the substrate and how exposed the elevation is, and we’ll point you to the right product. For sealants used across the rest of the building envelope, have a look at our facade range.