Repair tar layer below concrete tile roof?

Fergus · 21-11-2009 11:11PM #1

Hi folks..

I'm not sure what the correct term for this stuff is.. it's like a brittle tar covered hessian type of material that is between the concrete roof tiles and the rafters. House is late 1960s build.

Anyway, as you can see in the 2nd pic attached, the material has gotten torn in one area and there is quite a draft coming in from it. Where can I get some sort of this or something else to reapri it, and how do you adhere to it?

TIA

746watts · 21-11-2009 11:34PM

It's bitumen felt, replaced by current A1 felt which has a more fabric type pliability but water proof. A roll of A1 felt costs about 70euro and would cover half a roof, so you might find a neighbour with a scrap left over big enough to insert in your bitumen felt tear.
Felt is your last layer of defence as gale force wind can drive rain under your tiles. If you insert a piece with bottom edge of A1 felt between bitumen and tile with about 6 inches of overlap and top edge of A1 felt is inside bitumen felt and about 6inches of overlap. To keep it(A1) held against felt to prevent sagging you can use a timber batten to push it in contact with bitumen and tile and angle screw the batten ends to your rafters. Dont worry about the draught too much as rafters need air movements to prevent dry rot.

Fergus · 22-11-2009 01:30AM

Thanks.. I think I see what you mean. I'll keep a look out for any roof work going on in the area!

PeteHeat · 23-11-2009 02:08AM

Hi,

The easiest way to repair it is take off the tiles around the hole, thay way you can ensure the new piece is slid under the next lap above the hole and that it overlaps the rafters on both sides and you can get a good overlap at the bottom.

You will need to be able to remove the nails in the laths to allow the new felt slide under.

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Repair tar layer below concrete tile roof?

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