Condensation where flat roof meets pitched

[phatboy]

Hi all,

I've noticed the past week a bit of condensation forming on the back of the layboards. The temperature has been down to about 2degrees, and very wet until today.

The insulation is a bit untidy, but it is continuous, The space between the warm flat roof space and the loft is thoroughly insulated with 200mm Rockwool.

Everything looks fine from on the roof, however some of the top deck ply feels delaminated but no obvious route for water to get in (Continious EDPM, lapped well up behind the slates. Really wish I'd used OSB, lesson learnt)).

Any suggestions on cause and remedy welcome!?

Tim

 

[Wayners]

Put plastic over to test
Water on plastic surface is condensation
Water under is getting in from outside.

 

[noseall]

Hi all,

I've noticed the past week a bit of condensation forming on the back of the layboards. The temperature has been down to about 2degrees, and very wet until today.

The insulation is a bit untidy, but it is continuous, The space between the warm flat roof space and the loft is thoroughly insulated with 200mm Rockwool.

Everything looks fine from on the roof, however some of the top deck ply feels delaminated but no obvious route for water to get in (Continious EDPM, lapped well up behind the slates. Really wish I'd used OSB, lesson learnt)).

Any suggestions on cause and remedy welcome!?

Tim

View attachment 368635View attachment 368636View attachment 368637

Foam fix 50mm PIR onto the underside of the ply layboards, if you can access.