Mould within roof?

[zomex]

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

 

[Monkey Boy]

it's vented between the plywood and insulation.

Draw a cross section of the roof and post it

 

[ChrispyUK]

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

Generally 50mm between roof and insulation. Did you fit a vapour barriers?

 

[bobski]

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

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.

 

[zomex]

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.

 

[zomex]

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

 

[bobski]

Redsign and a rethink needed then mate.

 

[zomex]

Redsign and a rethink needed then mate.

Yeah I'm going to increase ventelation as much as I can including replacing the sofit with a full vented one.

 

[ChrispyUK]

Yeah I'm going to increase ventelation as much as I can including replacing the sofit with a full vented one.

Looks like a nice job mate. Useful info tbf as I’m part way through building my own garden room with a cold roof. Was considering different options for the soffits.

 

[zomex]

Looks like a nice job mate. Useful info tbf as I’m part way through building my own garden room with a cold roof. Was considering different options for the soffits.

Definitely recommend the fully vented one. Something like this:

Anthracite Dark Grey Vented Soffit Board

Our Anthracite UPVC Vented Soffit Board offers a modern solution for roofline ventilation and protection, combining functionality with an elegant dark grey finish. Featuring continuous air vents, this soffit board promotes consistent airflow to preve

www.plasticbuildingsupplies.com

Also venting from both ends is recommended.

Best advice I can give is don't make the same mistake as me. Think about internal ventilation also. A window that can open or some sort of extractor vent. My plasterboard is damp because I didn't think about this until now.

Considering I've not got the ventilation right and had a leak I'd say it's held up pretty well over 3 years.

Also think about where you're going to hang things and put patress in. That's one thing I'm going to fix as part of this. I didn't think about this and had to fit a piece of plywood behind my radiator to hit the studs.

 

[ChrispyUK]

Definitely recommend the fully vented one. Something like this:

Anthracite Dark Grey Vented Soffit Board

Our Anthracite UPVC Vented Soffit Board offers a modern solution for roofline ventilation and protection, combining functionality with an elegant dark grey finish. Featuring continuous air vents, this soffit board promotes consistent airflow to preve

www.plasticbuildingsupplies.com

Also venting from both ends is recommended.

Best advice I can give is don't make the same mistake as me. Think about internal ventilation also. A window that can open or some sort of extractor vent. My plasterboard is damp because I didn't think about this until now.

Considering I've not got the ventilation right and had a leak I'd say it's held up pretty well over 3 years.

Also think about where you're going to hang things and put patress in. That's one thing I'm going to fix as part of this. I didn't think about this and had to fit a piece of plywood behind my radiator to hit the studs.

I’m fitting an opening window/windows and French doors, although that’s to be finalised. I’m going to line the internals with osb before PB.

 

[zomex]

I’m fitting an opening window/windows and French doors, although that’s to be finalised. I’m going to line the internals with osb before PB.

Sounds like a nice job. Hope to see some photos

Lining with OSB first is a good move. If I had the funds and time again I'd do the same.

I did use 15mm soundboard though (ceiling fun by myself haha) so it's pretty solid. Currently working on the adding joists for the new window. Built the upstand already.

 

[ChrispyUK]

Sounds like a nice job. Hope to see some photos

Lining with OSB first is a good move. If I had the funds and time again I'd do the same.

I did use 15mm soundboard though (ceiling fun by myself haha) so it's pretty solid. Currently working on the adding joists for the new window. Built the upstand already.

Yeah, they’re a bugger on your own.

I’m just waiting on ‘a lift’ to get the back wall up and into place, then it’s all systems go. I’ve made a flitch beam to go all the way across the front which I’ll also prop so I can get the roof on. Can then decide what windows and doors are going in.