Condensation- big problem

[shan64]

I'm after some advice here! Had a new manufactured slate roof and velux windows fitted 4 years ago. A year later the same builder converted our loft, which is now the main bedroom. I noticed condensation dripping from the felt and asked a different roofer if he has any suggestions on how to get rid of it- this problem is bad in the Winter as there is no heating up there. The roofer said that poor quality roofing felt had been used- it's not breathable. He also said that the only solution is to remove the roof, replace the insulation and felt and then put the roof back on- obviously this is going to cost a lot! My questions are
1. Would it help if there were vents put in? At the moment there aren't any
2. Would it help if we had a couple of radiators put in? No heating up there at present
3. Is there any other cheaper but permanent solution than having the whole roof removed then replaced? He said he could use the same slates so we wouldn't need to pay for more of those.
4. Can we insist the original builder compensate us for not using the proper felt? Should he have asked if we planned on converting the room at some point or just used the breathable felt anyway? Surely the fact we had 3 velux windows fitted at the time should indicate that future conversion was a possibility??? I know the answer to this is no already but it's very annoying!
Any ideas welcomed. Thanks!

 

[JohnD]

1. Would it help if there were vents put in? At the moment there aren't any YES

2. Would it help if we had a couple of radiators put in? No heating up there at present NO

The idea of stripping it and putting on a new roof will be a major contribution to the roofers villa in Marbella.

BTW is there a bath or shower up there, or is all the moisture leaking up from the house below and the loft-occupants breath?

 

[shan64]

We have no bathroom up there- but we do sleep up there so most of the condensation is probably from us breathing.

 

[JohnD]

the other thing to look out for, water vapour and steam are lighter than air, so will rise up through the house from cooking and bathrooms (and hanging wet washing over rads which some people do!) so it helps to have automatic extractor fans.

Q.
Isn't the living area enclosed with plasterboard, vapour barrier, insulation and ventilated space before the felt?

 

[shan64]

Hi- thanks for your help. The area is enclosed with plasterboard, then insulation which looks like polystyrene tiles, then felt. The roofer who told us it needed to be re-done seemed to think that there wasn't adequate ventilation.
I am very guilty of drying our washing on the radiators! We have an extractor fan in our bathroom and I try to leave the window open for a while after bathing/showering too- it's too cold at the moment though.

 

[JohnD]

I am very guilty of drying our washing on the radiators!

You are a very wicked person. You are guilty of causing damp, condensation, rot and mould in your house.

You must know that every pound of water that you dry out of your wet clothes results in more than a pint of water lodging somewhere else in it. Would you throw buckets of water on the walls?

 

[shan64]

To be honest, I don't even think about where the water goes when the clothes are drying!! BUT I will from now on! Whenever it's dry outside, the clothes go out there, but we don't have a tumble dryer and I have to dry the clothes somehow, honest guv!

 

[JohnD]

You could put an over-bath line up, and leave the bathroom fan running.

That should save you £6,000 on a new roof.

 

[shan64]

So I should
a. Get vents fitted. Should there be vents at the top and the bottom of the roof?
b. Stop drying clothes on the radiator

Would vents solve the problem or just reduce the amount of condensation?