Howling gale in my loft!

[AL_n]

There is a powerful draft up in my loft. I am well aware that a loft should be ventilated, but if the wind whistles right through it's going to suck a lot of heat out of the house in Winter. I've just added 170mm of rockrool to the loft, but I'm wondering if it would make sense to cut down on the breeze that's getting in. It's an old stone-built house (1850s) I can see light getting in through some holes in the soffit at one place, and part of the roof has no felt inside, so the wind gets in between the roof tiles there. In the interest of thermal efficiency, should I block some of the sources of the drafts?

Thanks

Al

[The Natural Philosopher]

Better is to cover the insulation with something windproof.

Boarding, or simply plastic sheet maybe.

Fixing holes in eaves that were always built that way is a thankless task IMHO.

[AL_n]

The Natural Philosopher wrote in news:i6rbum$bqe$2 @news.albasani.net:

Thanks for the suggestions. I was wondering how wind-proof rockwool is... One thing I was thinking of covering the existing rockwool with the so- called "space-blanket" rolls seen at B&Q - a layer of rockrool covered on each sode by reflective plastic material.

Al

[The Natural Philosopher]

Rockwool definitely loses efficacy in a howling gale, so do whatever it takes.

[geraldthehamster]

Agreed, and to increase it to at least 300mm.

Cheers Richard

[Bob Minchin]

Something breathable would be better than ordinary plastic sheet to reduce the risk of condensation forming and eventually rotting the ceiling rafters.

Bob

[geraldthehamster]

That's probably true. Having said that, in an ideal world one would have a vapour barrier underneath the insulation, to stop warm moist air rising into the loft space from the house.

Cheers Richard

[js.b1]

Often wondered, would Dulux Plaster Seal (interior) do sufficiently - either on top of the ceiling or underneath where it is bare? There are various other sealing products available, which can then be painted.

[Bob Minchin]

yes that would be ideal but how many installers of extra insulation think to add such a vapour barrier??

Bob

[geraldthehamster]

I should think approximately none, especially as it would involve lifting old, filthy insulation. More of a practical proposition if you are insulating for the first time, of course.

If you don't have it, then I think the earlier observation, about making sure anything overlaid to prevent blowing around should be pervious to moisture, is right. Though if you've used rolls of insulation, just laying a few wooden battens around should hold it down all right. Then again I've never been in the OP's loft.

Cheers Richard

Cheers Richard