Mould within roof?

zomex

zomex

Member
Hello all,

My garden office I finished 3 years ago.

Was given a second hand window which now needs to be replaced (big mistake it leaked - leason learned).

I've exposed the ceiling/roof and noticed some black spots on the plywood. Is this mould? Would it be wise to increase the ventilation?

The roof is a cold roof, it's vented between the plywood and insulation. It feels very dry in the roof space, but if the black spots are mould it would suggest otherwise.

Walls are bone dry which I'm happy about.

Thanks
 

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zomex said:
Hello all,

My garden office I finished 3 years ago.

Was given a second hand window which now needs to be replaced (big mistake it leaked - leason learned).

I've exposed the ceiling/roof and noticed some black spots on the plywood. Is this mould? Would it be wise to increase the ventilation?

The roof is a cold roof, it's vented between the plywood and insulation. It feels very dry in the roof space, but if the black spots are mould it would suggest otherwise.

Walls are bone dry which I'm happy about.

Thanks
Click to expand...
Generally 50mm between roof and insulation. Did you fit a vapour barriers?
 
zomex said:
Hello all,

My garden office I finished 3 years ago.

Was given a second hand window which now needs to be replaced (big mistake it leaked - leason learned).

I've exposed the ceiling/roof and noticed some black spots on the plywood. Is this mould? Would it be wise to increase the ventilation?

The roof is a cold roof, it's vented between the plywood and insulation. It feels very dry in the roof space, but if the black spots are mould it would suggest otherwise.

Walls are bone dry which I'm happy about.

Thanks
Click to expand...


Looks the moisture didn't vent quickly enough after the leak.

Window replaced, if it's vented like you say and there's a breathable membrane in there, it should go back ok.

More info needed though.
 
Thanks for the replies.

I don't remember the window leaking on the side of the photos. The other side where I know it did leak has a lot less black spots. So it must have been leaking worse where I wasn't seeing it.

There is a vapour barrier on both the walls and ceiling. Walls are completely bone dry behind the vapour barrier. Plasterboard was slightly damp but I have 0 ventilation in the room itself as the window doesn't open. New window will open and also has vents built in. I'm hopeful this will control that.

Ceiling also feels dry. Perhaps as someone suggested it's not recovered since the leak? But that was a long time ago as I ended up covering the window with plastic to stop the leak. So it's not been leaking for over a year.

50mm ventilation gap in roof. Plus the furrings go in the opposite way to joists to give further ventilation.

I was given a lot of the stuff from a mate who had left overs from his garden room. This ended up being a mistake. For example the overhang has a plastic fit underneath (don't know the name of it). I cut and added some vents but I don't think it's enough. One option I've considered is replacing this with a fully vented one. I'll send a photo of what I mean today.
 
I'll get a better photo later.

If you zoom in under the roof hang you'll see a mix of 50mm lights and vents. I don't think the vents are enough and believe replacing this with a new fully vented one is going to be the way to go.

PS: Not a bad gate a cladding for a website guy
 

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