Damp patches after heavy rain on roof rafters and membrane

[rob_em]

Hi,

After heavy rain Im noticing in my loft areas where damp patches show between membrane and rafter. Im a bit ocd with this issue as would like to ask is it much to worry about the structure of rafters will they rot ? it only happens afer heavy rain and only in one specific area corner of the house. North corner.

 

[blup]

Identify where and how the rain is getting in, and be aware the source might be elsewhere eg a broken tile higher up the roof with water tracking down to where it is damp. It does need addressing al though you’re a long way off from rotting rafters

 

[rob_em]

Thanks blup. I've already checked tiles above and did not find anything. Im suspecting 2 things. First is overlap and pitch which is small. But on the other side of house it's same and it's fine... The other thing I think is that the membrane is touching the bottom of the tile somehow and water is getting on it

 

[blup]

It could be either or both of those, the fact it doesn't happen on the other side isn't really relevant because you have the problem where the problem is. There are time served roofers in the roofing section of the forum, it would be worth asking a mod to transfer the thread there.