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- 27 Aug 2020
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Hi all,
I’m after some advice on a condensation issue I’ve got in my recently built shed. I’ve read various forum posts but can’t seem to find a solution to my problem.
The floor is 25mm ply timber suspended. Standard stud walls with feather edge cladding and no internal sheathing yet, although plan on putting 12mm OSB up. Roof is primarily corrugated bitumen roof sheets plus a couple of clear PVC sheets. I’ve not put any insulation in anywhere as I won’t be heating the space. I’ve attached a photo of how the inside currently looks.
I’m getting really bad condensation on both the clear sheets and bitumen sheets (particularly bad on clear sheets). Water drips down directly from the sheets or onto the purlins and then down. The issue is worst in the morning after a cold night, I guess due to the inside temperature being slightly higher than the outside.
I think one factor may be that there’s a layer of impermeable plastic membrane between the studs and cladding. This was initially put up just to make the structure watertight before cladding but we ended up leaving it in place to give the non-pressure treated studs some protection from water. Could it be that this alone is driving the condensation issue? I’d be surprised if that’s the case as there are plenty of gaps for ventilation and surely the feather edge (+ OSB when I add it) wouldn’t allow the humid, warm air to escape anyway.
Any other ideas for how to resolve without spending a fortune? Would lining the underside of roof with loft insulation and thin ply sort it? I’m wary of this as have read that this can lead to the insulation becoming sodden and ceiling collapsing!
Thanks very much for you advice.
Jack
I’m after some advice on a condensation issue I’ve got in my recently built shed. I’ve read various forum posts but can’t seem to find a solution to my problem.
The floor is 25mm ply timber suspended. Standard stud walls with feather edge cladding and no internal sheathing yet, although plan on putting 12mm OSB up. Roof is primarily corrugated bitumen roof sheets plus a couple of clear PVC sheets. I’ve not put any insulation in anywhere as I won’t be heating the space. I’ve attached a photo of how the inside currently looks.
I’m getting really bad condensation on both the clear sheets and bitumen sheets (particularly bad on clear sheets). Water drips down directly from the sheets or onto the purlins and then down. The issue is worst in the morning after a cold night, I guess due to the inside temperature being slightly higher than the outside.
I think one factor may be that there’s a layer of impermeable plastic membrane between the studs and cladding. This was initially put up just to make the structure watertight before cladding but we ended up leaving it in place to give the non-pressure treated studs some protection from water. Could it be that this alone is driving the condensation issue? I’d be surprised if that’s the case as there are plenty of gaps for ventilation and surely the feather edge (+ OSB when I add it) wouldn’t allow the humid, warm air to escape anyway.
Any other ideas for how to resolve without spending a fortune? Would lining the underside of roof with loft insulation and thin ply sort it? I’m wary of this as have read that this can lead to the insulation becoming sodden and ceiling collapsing!
Thanks very much for you advice.
Jack
