Help Please -Slate Roof - No felt - just backfill

erb

I have a 1930s semi with a slate roof that typically for the year built has no felt. Instead there is a kind of mortar backfill or at least there was but most of it has now fallen off and has made a right mess on top of the insulation. Don't see any problems with the slates or timbers but the mess makes life difficult for storing stuff in the loft.

Is there any need to do any repairs and if so what it the best solution?

pcspike

Hi,

Yes this wascommon practice in those days for the purpose of preventing draughts andreinforce the slates security. You can remove any loose mortar and replace it.The other problem that you could find is condensation. A solution would be afoam insulation which is sprayed between the rafters, a solution that insulatesand secures in one. If you go down this road ensure that the timbers are ingood condition first.

Hope this helps

teneighty

NOOOOOOO!

Dont go for the sprayed foam insulation. It will cost almost as much a full re-roof, cause more problems with the slates sweating above the foam and you wont be able to re-use the slates when you do need to re-roof.

If you can live with it for now it will not cause any serious issues. The roof is now 80 years old so possibly the nails and battens are coming to the end of their life and you may be looking at a re-roof in the next 5 years anyway, hopefully you can re-use the old slates.

Make enquiries with local reputable roofing contractors to get their opinion and costings.