On Saturday, 11 November 2017 19:38:56 UTC, Michael Chare wrote:
On 11/11/2017 18:24, Bob Minchin wrote:
Michael Chare wrote:
Is there anything better than black exterior mastic (frame sealer) to
repair a foot long crack in a bitumen felt roof? The crack is near the
edge where there is a lip to control direction of water flow.

Some has used what is now hard grey stuff to repair some previous
blemishes in the tiles. It is subsequently cracked.


You can get roof sealant cartridges which I think are bitumen based and
should retain some flexibility.

Thank you. Screwfix sell Mapei Backfill Bitumen sealant cartridges.
They are twice the price of their other roof sealant products. I wonder
if they are any better.

Bitumen is cheap stuff. General approach to roof cracks:
Fill crack with sand & bitumen
Apply bitumen
Apply cloth. Anything can do but synthetic fibres last better.
Apply bitumen
Apply sand.

* for bitumen read bitumen + solvent, sold in gallon cans.


NT