Dormer membrane wrap - in window opening?

[DiscoDroid]

Hi everyone. Putting up a timber framed dormer. Wrapping with a breather membrane. Should the membrane be cut & pulled though the window opening, installing the window ‘over the top’ of the membrane? Or should the membrane be trimmed around the exterior of the window opening?

Many thanks!

 

[^woody^]

Returned around all sidesof the opening.

 

[DiscoDroid]

Thanks Woody,

A post ages ago suggested siliconing the membrane to the structure at the return. Is that the done thing?

 

[noseall]

Thanks Woody,

A post ages ago suggested siliconing the membrane to the structure at the return. Is that the done thing?

We use staples...

Cedral2

• noseall
• 3 Dec 2017

 

[^woody^]

Thanks Woody,

A post ages ago suggested siliconing the membrane to the structure at the return. Is that the done thing?

No. As nosey says just return the wrap and staple it. Add a little piece at each corner to allow for the cuts and ensure the frame is completely covered.

You only need to mastic when it comes to the window/door frame and cladding junction.