Loft warmth/insulation

sevenhills

I have recently boarded out my loft, not concerned about the insulation, but there are slight draughts under the roof tiles.
I know some people advocate ventilation, but I can see slight movement of the cobwebs under the roof tiles/backing.


Does this need rectifying, and if so how?

Davesnave

I would hope to see more movement of air in my loft than that on a day like today. With plastic soffits and their built in ventilation, the wind fairly whistles through my loft. No condensation worries though.

If you have adequate insulation (270mm) directly above your ceilings, then a somewhat draughty loft isn't a problem, though I guess you can't have that much if the place is boarded-out. I laid a central walkway with Kingspan underneath and suspended plywood shelving in the roof truss 'Ws' to get over the problem, but nothing very heavy goes on those.

Tom99

A slight draft sounds good. What do you mean by 'backing'?

Grenage

Tom99 wrote: »

A slight draft sounds good. What do you mean by 'backing'?

I assume he means felt.

sevenhills

Tom99 wrote: »

A slight draft sounds good. What do you mean by 'backing'?

Looks like black layers of rubber/plastic material.

Davesnave

sevenhills wrote: »

Looks like black layers of rubber/plastic material.

It's probably the stuff made from bitumen impregnated material which doesn't 'breathe' like modern membranes. That's a disadvantage, because in cold weather and higher humidity water can condense out of the air on it, drip off and cause dampness.


That's why it's good to have some air flow up there, to keep it dried-out, just like washing dries better on a windier day.