Wet roof, - on the inside !

Dec 01, 2003 8 Replies

Hi all,



We've just moved into a new house which has a tiled roof (good condition), on top of felt, - which then in turn has fibreglass insulation.



Inside the loft, we have discovered that the whole roof is wet. It appears to be condensation. There is little ventilation around the eaves due to (I suppose), the fact that new PVC facias have been fitted.



Is there a simple solution to this? The loft hatch has a slight gap around it, but is part of a loft-ladder system which means replacement is likely to be costly and/or complicated.



Thanks in advance.



H.


I had this problem with a new roof as well. Called out the roofer who put four tile vent thingies in. Two on each side of the house. Loft dried out within 2 weeks. Didn't charge me a fitting cost as I argued that he should have known these were required in the first place.

Bill

Yes. Drill fascias to take vents. Cheap, and quick.

|Howie wrote: | |> Hi all, |> |> We've just moved into a new house which has a tiled roof (good |> condition), on top of felt, - which then in turn has fibreglass |> insulation. |> |> Inside the loft, we have discovered that the whole roof is wet. |> It appears to be condensation. There is little ventilation around |> the eaves due to (I suppose), the fact that new PVC facias have |> been fitted. |> |> Is there a simple solution to this? | | |Yes. Drill fascias to take vents. Cheap, and quick.

Looks as if I will end up doing this. Thanks.

However, I am concerned that there is rockwool insulation on the inside of the felt roof. As it is soaked with condensation would it be better to remove it and ensuer there is a thick layer on the loft floor - rather than the underside of the roof? I always thought that a cold loft and a warm house is the right way to go about it ! Am I right, - has the previous owner been TOO diligent here?

H.

I aplogise. It was not obvious from the original post where the insulation was. If teh inside of the insulation UP IN THE ROOF is wet, then its doing no good anyway, because its obviously cold INSIDE the loft space: A 'warm roof' where the loft space is warm, should not be working this way.

Unless there is need to keep the loft warm, I would certainly recommend you proceed as you outlined - let the roof be cold and ventilated, and the insulation over the rooms. Reme,ber to seal from draughts if possible (boarding is good) and lag pipes very well if you go to a 'cold' roof..

It sounds like whoever did it knew very little about it. You didn't buy it off IMM perchance?

A loft gets a hell of a lot of steam from below. However it is not draught proof even without the proper vents. Tiles and roofing felt are not sealed and wind can blow through them. It sounds like the previous owner intended to board the attic over and move in there.

You don't have to throw the insulation away as it will dry out. Either lay it on boards over the floor or roll it up if possible and dry it in your garage or shed. We have had some damp murky weather recently; would it have been holding some of that perhaps?

So what stopped it dripping dry?

I was probably exaggerating a _little_ about it being 'soaking' wet. But it _is_ wet in places because the cold felt is catching condensation through it.

I'm glad my suspicions are probably founded. I will remove the rockwool from the underside of the roof and draughtproof (as best possible) my loft-hatch.

Appreciate all answers I had.

H. |So what stopped it dripping dry?

Hi Howie. There should be a gap between the insulation and the roof proper, without one damp can be a problem. Best check for that.

Regards, NT

| |Hi Howie. There should be a gap between the insulation and the roof |proper, without one damp can be a problem. Best check for that. | |Regards, NT

Hi,

Yep, - there isn't! So this confirms that it was fitted badly or (probably) shouldn't have been fitted at all.

I will rip it all out when I get a free afternoon.

Thanks for all advice.

H.

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