Eaves ventilation

In message , David writes

Hmm.. builders seem to have latched on to the idea that porous roofing membrane makes eaves ventilation redundant.

Building Control don't have the same view here! They insisted on a significant gap between the membrane and any loft insulation.

In message , Jim K writes

No. Conventional pitched rafters but *included attic* (chalet bungalow).

Tim Lamb posted

When I insulated my new roof space I followed BC's instructions of leaving a ventilation gap at the eaves (by not running the rockwool right up to the edge). Now I'm getting birds roosting in the loft, and leaving bird s*it everywhere. Mind you it was just this last winter, which was a pretty cold one.

In message , Jim K writes

I've used both. BC didn't like 200mm of Rockwool between the rafters because he felt it impacted on the space for ventilation. I changed to

The small attic spaces have 100mm PIR between floor joists and 100mm Rockwool over all.

That is why you have a board along the eaves to keep wildlife out, then drill holes and put grilles in which have a mesh which stops birds, bats, mice etc. getting in.

Cheers

Dave R

Jack do you not have soffits to keep the birds out? If you do not then I do not think leaving a gap in the insulation or not would keep them out, you may have been lucky until this year.

Richard

Or, if fitting new boards, use continuous fascia vents which are screwed to the top of the board and hidden by the gutter/overhang of the slates/tiles.

Makes sense as so called porous material is only so until muck and growths block it up. Brian

I wouldn't bother ... millions of houses were built without them with no problems .....

Or even a mesh which stops wasps getting in.

You presumably didn't follow his advice on installing a grill or mesh?

The builders who installed the roof itself would have done that.

Er - so how are birds getting into your loft?

I don't know. When you have a constructive suggestion to make I'll be glad to hear it. Until then ...

Here's one - stop talking rubbish.

Either you have mesh (etc) or you don't. Which one is it?

And if not, why not?

There an old idea of venting before the uses of breather underlay. The system was called cross flow system

The best way to stop condensation is to vent the ridge

Was thinking that - certainly not a standard fitment in any Victorian house I've seen for example. And I can't think that rockwool is an especially nice nesting material . . .