Hi,
I’m part way through building a lean-to extension with a flat roof.
Due to space and other restrictions it’s a cold roof but has plenty of ventilation and gap.
I’ve built the roof structure and fitted the firrings for the slope and am ready for the osb deck then epdm roof.
Talking to a few people about it, some have suggested I lay a breathable membrane above the firrings/below the deck, with a drape so that and moisture can fall away to the soffits.
This would be trapped tight between the firrings and the osb deck but could drape between the joists (at 400mm centres).
Is this a good/bad idea?
Is it overkill or belt and braces?
Could it cause more problems than it causes?
I’ve got the membrane and can always use it on another project (I’m going to build a shed)
Any advice or guidance would be gratefully received, I’m hoping to do the roof in the next few days as the weather is nice.
I’m part way through building a lean-to extension with a flat roof.
Due to space and other restrictions it’s a cold roof but has plenty of ventilation and gap.
I’ve built the roof structure and fitted the firrings for the slope and am ready for the osb deck then epdm roof.
Talking to a few people about it, some have suggested I lay a breathable membrane above the firrings/below the deck, with a drape so that and moisture can fall away to the soffits.
This would be trapped tight between the firrings and the osb deck but could drape between the joists (at 400mm centres).
Is this a good/bad idea?
Is it overkill or belt and braces?
Could it cause more problems than it causes?
I’ve got the membrane and can always use it on another project (I’m going to build a shed)
Any advice or guidance would be gratefully received, I’m hoping to do the roof in the next few days as the weather is nice.
