Is this dripping in the loft normal??

[uptown47]

Hi all,

I wondered if you could help me. The loft / attic in my house was converted into a small room (by the previous owner). This conversion left two side 'eves' (small crawl spaces where boxes could be stored).

I decided to tidy up the wiring in the crawl space, board it out and then use it as storage.

After boarding it I noticed patches of moisture around the loft. It "appears" (but I might be wrong) that it is condensation dripping down from some insualation-type stuff that has been shoved up in-between the joists into the part of the loft that is now a small room.

I've attached some pictures to try and illustrate what I'm talking about....

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• uptown47
• 6 Dec 2012
• 1

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• uptown47
• 6 Dec 2012
• 1

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• uptown47
• 6 Dec 2012
• 1

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• uptown47
• 6 Dec 2012
• 1

Is this just condensation?

Is this something to worry about?

The damp patches seem to be in various places (I've spotted 4 so far).

Is there anything I can do to stop this?

Many thanks for any help you can give me. As you have probably gathered by now I have no experience of roofing whatsoever so would love your opinions / comments on this.

Many thanks

John

 

[freddiemercurystwin]

By joists presumably you mean rafters? Any insulation between the rafters should not be pushed up against the underside of the felt but should leave a 2" gap between the insulation and the felt. You should also have continuous ridge vents.
Like this:

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• freddiemercurystwin
• 25 Apr 2010
• 24

 

[uptown47]

Hi Freddie,

Thanks for the info.

Yes, I did mean rafters

There is a slight gap but I don't think it's 2".

What are "continuous ridge vents" ?

Once again, excuse my ignorance and thank you for your help.

Cheers

John

 

[freddiemercurystwin]

You have ventilation points at the eaves to let fresh air in, in an ideal world it will then be sucked up the 2" gap between the insulation and the felt and be extracted through a vent at the ridge taking any vapour with it thus removing the condensation risk. When was the conversion done, was it official ie to Building Regulations? It looks kinda modern!

When you look at your roof from the outside can you see any tile vents near the ridge or a ventilation gap between the ridge tiles and the first row of tiles?

It could be that the insulation is blocking the ventilation gap and needs to be rectified.

This is the theory of what you need to achieve:

Ridge vents, these can be proprietary products fitted when the loft was converted, bit of a naff example but the following should give you the gist:

 

[uptown47]

Freddy,

Thanks again for your excellent help.

I've done quite a bit of work up there in the recent weeks. Whenever I go into the attic it is very cold compared to the rest of the house and, as I work with the hatch open, I'm wondering if it could just be the warm air rising from the house and then condensing against the cold felt and cold foil stuff that surrounds the insulation slabs?

Whaddya reckon?

Or should there be no condensation at all if it is done correctly??

Your diagram of how the roof should be constructed has been extremely helpful. I finish work early on a Friday so will be back in the attic this afternoon. I'll check to make sure that there is not insulation blocking the air flow into the loft and I'll also check to see what sort of distance I've got between the insulation blocks and the felt.