UPVC D/G window in shed

[Howie1000]

Good morning all, I’m part way through building my workshop/shed. It’s framed with 4x2, has cellotex insulation, 11mm OSB inside and out, then externally clad with featheredge.
I have a 3ftx4ft UPVC double glazed window and UPVC double glazed french doors to install, I’m not 100% sure of how to do it. I’m going to build the wood frame work for the door and window with a 5mm gap, but it’s the water proofing part that is stumping me. The window has a sill attached already.
Many thanks !
David.

 

[RogerM]

Maybe a photo or two would elicit some replies. From what you have described, I would anticipate that you could do the same as I did with a shed in which I installed an off the shelf window from Wickes. In my case I installed the window flush with the front edge of the OSB sterling board wall and then stapled some DPC strip to the OSB wall which overlapped the window. The edge of the dpc was sealed to the window with a bead of CT1.

I surrounded the window with tanalised boards overlapping the window by about 5mm. Then the shiplap was just nailed to the sterling board, and the butt join was sealed with CT1. Any water getting past that would not get past the DPC strip underneath. I tackled the door in the same way, and you can see the DPC strip either side of the door in one of the photos in the original thread. The original build thread is here .

 

[Mick Brightmore]

Expading foam and sealant is generally used to seal around the doors and windows, maybe some architrave if the gap is too excessive.