Re-roof?

[jackg]

Building is an L shape, one single pitch on one leg and two pitches on the other L with a small hip section. 2/3rds is accommodation and the rest is two outbuildings.
Felt is coming down in four to five places, I have repaired four other areas with breathable felt. No leaks.
The roof was built in 1981-2.
How long do I wait before refelting.
The tiles are clay Double Roman.
I am contemplating doing the work myself as it is single storey and a large area so expensive. I should be able to re use the tiles, but may require 100 or so replacements.

 

[noseall]

Why is the roofing felt "coming down"?

The worst that should be happening is a wee bit of membrane rot at the eaves. The roof tiles are what keep the water out in any case.

 

[jackg]

In some places the left is coming down because it is shearing on the edge of the rafter
https://www.flickr.com/photos/67356568@N05/17130699046/

In other places in an outhouse which is single pitch with a 6" timber strip at the top of the pitch which covers the top part of the top row of tiles, this may not be water tight I am not sure.
The picture looks upto the top of the pitch and the end wall
https://www.flickr.com/photos/67356568@N05/17130698596/in/photostream/

 

[freddiemercurystwin]

There's no need to replace the felt unless the tiles are leaking? The felt is a back up in case of a broken tile and to keep the inside dry during re-roofing. Millions of houses do not have any felt.

Replace the felt when you need to re-roof.

 

[jackg]

Thank you for that gem.