Lean-to roof repair - tiles on mortar / felt / mortar / wall

[jason1958]

Relative has the following 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.

Q - How can I effect a reliable roof repair?

Is it a case of wedge & lift tiles, put *impermeable* roofing membrane over the wall on mortar, overlapping it onto the existing felt, bedding the tiles onto the membrane with mortar?

Q - What is the correct & best membrane to use?

Felt rolls are too heavy for me to handle and I'd rather pick up a proper membrane for when the roof is properly redone (more weatherproof interlocking tiles re 22-degree pitch and a lot of insulation).

 

[Alastairreid]

whats the rest of the verge like jason? it may be a better idea getting rid of the wet verge and installing a dry system.

something like this.

Untitled

• Alastairreid
• 15 May 2009
• 5

failing that if you can post a pic or two we can advise better.

 

[jason1958]

Thank you for your reply.

I will get a photo in the next few days and post it.
The relative (82) indicates it has been a damp area for 30yrs. No mould, just what I would characterise as "permeating damp".

I am currently buried in another task re marmox & celotex insulating the wall below (removing tiles from 2.5ft without breakage, clearing to wall, insulating, refitting everything, new trim, grout, repeat on next 2ft so minimal disruption re room still usable).

So will post back shortly