In article
,
js.b1 wrote:
A relative has lean-to roof.
Concrete marley etermit tiles on batons, felt, T&G close-boarded,
rafters. 22-degrees.
Close-boards stop at the double-brick wall, tiles are then bedded on
felt, on mortar, with mortar edging.

Over the double-brick wall at a north-facing corner for about the
bottom 15" the mortar is falling out and the felt is disintegrating.
Interesting population of woodlice. The result is a damp stained
plaster-skim over browning for about 6-inch below and a plywood
cupboard has delaminated rather spectacularly over about 3-inches. It
is a kitchen below so damp loves company on a north facing wall re dew
point. Ventilation is now 220+270m3/hr, open gas appliance removed.

Q - How can I effect a reliable roof repair?

Mortar edging on its own is a bodge. Replace it with lead flashing.

--
*If at first you don't succeed, then skydiving definitely isn't for you *

Dave Plowman London SW
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