leaking pitched roof

[Ashley4569]

I have a pitched roof on an extension that was built in Nov 2010. It has two velux windows in the roof also.
When the builder installed the insulation, it had lain on my back garden for two days and got soaked in the rain so it was therefore put in when wet. When the inside ceiling had been plastered we noticed water patches appear in two bands running horizontally across the ceiling. The builder said it was because the insulation was wet and it would dry out. However, particularly after heavy rainfall the patches reappear as bad as before. The roofer has been back and removed several tiles and can find no sign of a leak. In fact the waterproof membrane is bone dry on top but when you lift and put your hand underneath, the insulation is soaking and the rafters are already showing signs of mould. Obviously I'm worried that everything inside the roof is just going to rot. Any advice?

 

[noseall]

Condensation.

Lack of vents.

 

[Ashley4569]

Thanks for your reply Noseall

Would this still be the case although the patches get worse after heavy rainfall?

 

[Ashley4569]

Hi
Can anyone tell me if tile vents on their own are going to be sufficient or will I need soffit vents as well.
Also, does the wet insulation need to be stripped out and replaced with dry or will sufficient ventilation dry everything out.
When we last looked under the membrane (which incidentally is supposed to be breathable) the roof timbers were already showing signs of mould and the roof has only been on for 3 months!
Thanks.

 

[datarebal]

You cam get condensation even on the back of breathable.
Especially on new builds during the drying out period.
If the insulation was soaking wet , then It was a very silly move fitting it.
Can smell like cats pee..
Increase the venting, vent tiles should help but soffit or over fascia vents aswell would be best..

I think i'd replace the insulation.