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How to seal gap between polycarbonate roof sheets and adjacent brick wall?

dyfuse
Getting Established

How to seal gap between polycarbonate roof sheets and adjacent brick wall?

Hi workshop community,

 

I have a decked pergola area with polycarbonate roofing adjacent to a brick wall. There is a gap of approx 1 cm between the edge of the polycarbonate and the wall and during heavier rain, the deck ends up getting wet! The previous owner who had the pergola installed did not have any flashing or similar put in to prevent water leaking onto the deck.

 

As a temporary measure, I've inserted a 10 mm polyethylene foam in the gap which understandably fails to improve the situation - the water just ends up running behind the foam and down the wall. 

 

Can anyone suggest a solution to seal the gap? I would be interested if anyone had a solution other than flashing that might be just as effective.

 

Cheers,

Daniel

 

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Re: Sealing gap between polycarbonate roof sheets and adjacent brick wall

Thanks for your replies @Jewelleryrescue and @MitchellMc! These are very helpful and also gives me an idea of some of the different solutions available.

 

@MitchellMc, if I choose the clear barge capping solution you first suggested, once I place the barge cap so it sits against the wall in the orientation as per your diagram, how would you suggest I best glue it to the brick wall? And how to do so without rain water getting in and running down behind the barge cap (in the gap indicated by the orange arrow in the diagram below)?

 

Also should I be concerned with any water dripping down the wall via the mortar 'channels'?

 

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Re: Sealing gap between polycarbonate roof sheets and adjacent brick wall

Oh   @dyfuse @MitchellMc 

 

 

I  See that brown strip on the wall is foam running along the polycarbonate edge, I hoped was timber but you  where already thinking on the right track as to a seal.

 

Well @dyfuse try use that as your wall to angle  seal or what ever you choose against as the foam looks like cement expansion foam  at 10mm thick that should depress into most mortar joints by screwing it flat and tight enough to form a seal but to do this you  will will need to screw angle  in multiple short gaps every 30mm or every 50mm or a  vertical mortar joints   if you use thicker wall 3mm 5mm aluminum it wont counter flex away from foam  compression.

 

Well @MitchellMc  has that solution for that design so  follow his  suggestion s it will work too,  Both our ideas will work  :smile:

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: Sealing gap between polycarbonate roof sheets and adjacent brick wall

You'd glue the flashing to the wall with Sikaflex 11FC, @dyfuse. The bead of Sikaflex will fill the mortar lines and prevent water from travelling down the rear side of the flashing. 

 

Looking at your image again, that polycarbonate flashing will touch the roof timbers when you place it into position. So, you'll need to cut it to fit around them or go with the other option of back-channel flashing or steel barge capping.

 

Mitchell

 

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dyfuse
Getting Established

Re: Sealing gap between polycarbonate roof sheets and adjacent brick wall

Thanks for clarifying @MitchellMc. I agree the polycarbonate flashing will be issue to fit in the gap between the roof timbers and the brick wall, and I'd prefer not to cut it.

 

I'll try the back-channel flashing option with the Sikaflex 11FC and see how I go.

 

Thanks for all your help @MitchellMc and @Jewelleryrescue!

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