Leaking Roof - Parts of felting rotting

[Ray1]

Hi,
I have a leak in my roof and a patch of felt about 0.7 metres long and 0.3 metres wide has rotted and come away from a roof
it is an attic roof and the felt is nailed to battens - I am just wondering about how best to repair this.

Does it need new felting adding by taking the tiles off the roof or could I do it internally via the attic?

also is there any kind of spray/paint I could use to seal the leak between the slates to stop the leaking onto the felt?
TIA

Ray

 

[Mary_Green]

Had a similar situation a couple of years ago — part of the felt under the shingles started deteriorating and eventually led to small leaks during heavy rain. It started off minor, but the damage underneath grew faster than expected, especially around joints and near the edges where water tends to pool.

What really helped me back then was reading through a breakdown of the typical repair steps and what to watch out for during inspection and replacement. It gave me a better idea of whether I could handle parts of it myself or if it was time to call in someone experienced. I ended up learning a lot about common repair approaches and how pros usually handle that kind of layered damage.

Definitely recommend doing a full inspection under the felting if you can safely access it — sometimes it’s not just about patching the leak, but checking how far the rot has spread.

 

[Ray1]

Thank you for your reply. That's really helpful. I will aim to do a full inspection and check the extent of the damage.