New flat roof - Problems

[bobcatt777]

Hi every body

Four weeks ago I had a new flat roof installed on my garage due to a fire including new boards, joists, felt etc etc.

After 3 weeks all the boards in the roof are covered in black mould. I spoke with the roofer who said this is normal as it was raining when he did the work. He suggested I treat the mould and it will be ok.

I'm concerned that the roof has not been installed correctly. Should I be worried? Any ideas?

Thanks -picture of boards below

 

[freddiemercurystwin]

It's probably caused by condensation due to a lack of ventilation.

 

[^woody^]

It's probably caused by condensation due to a lack of ventilation.

Due to lack of insulation more like.

Certainly not a defect though.

 

[tony1851]

Would you normally insulate a garage flat roof?
The mould does seem excessive - is the garage open to a utility room/kitchen, or is vapour getting in some other way, perhaps?

 

[bobcatt777]

Hi thanks for all your replies. The garage does have a double air brick.

The garage is in a block. Not attached to a dwelling etc.

I've always had a garage in a block and never had a problem
Like this before. I'm still thinking it has not been installed correctly? as there is no mould on the joists. Surly if condensation was a problem it would be on them also?

I also have a few odd bits of wood in the garage with no mould on

Again any ideas would be appreciated thanks

 

[^woody^]

Black mould spotting can't form on penetrating water. It can only result from condensation. That's why it can't be a defect and that's why insulating the deck would have prevented it.

 

[catlad]

What exactly is that we are looking at plasterboard?

 

[bobcatt777]

What exactly is that we are looking at plasterboard?

Hi no it's plywood

 

[catlad]

I have never had that issue, what was the roof before and what is it now ie. felt grp rubber?

 

[bobcatt777]

Hi. It was felt before and felt now.

I've never had this problem either.

I'm sure the roof hasn't been installed correctly.

 

[^woody^]

I'm sure the roof hasn't been installed correctly.

Why? Is it leaking

 

[bobcatt777]

I'm sure the roof hasn't been installed correctly.

Why? Is it leaking

No. I own a few garages and have never seen this in a "new roof" before.

 

[^woody^]

Perhaps it's different ply with different glue

 

[freddiemercurystwin]

Maybe the plywood is crying? Maybe it wanted to spend its life used as an exposed soffit getting an occasional cheeky glimpse down ladies cleavage's but instead it faces a life in the dark in a cold and wet garage?

 

[^woody^]

I've just seen this on the BBC:

"South West Water customers should drink bottled water until further notice."