Roof felting in some areas - rotting/crumbling - why ??

[utterlydiy]

As we've had dry weather the last few days, I've been cleaning and tidying the Upvc cladding around house.

Found as most houses in their lifetime have facia/barge boards that need replacing, on two corners of the roof on the north facing side.

To my dismay I also found the roof rafter to be soaking wet and really rotted back by approx 1mtr from the corner and also some tile battens. The tiles are red sandish flat concrete type tiles.

The reason found was that the felting is/had crumbled letting water through to the timbers. The tiles over hang the fascia board by approx. 50/70mm and the tile edging is sealed with cement (which is sound). The wind very rarely drives any rain on to this side, mostly from the south west at the front of the house.

What would cause the felt to rot/crumble in this area, where the rest across the roof looks sound. ??

thanks

 

[Alastairreid]

Uv light and exposure to the elements causes the felt at the eaves to degrade, solution is to install eave trays which are uv resistant, relatively inexpensive and not rocket science to install.

The rot on the tile batten at the verges is caused by the mortar infill at the undercloak cracking, absorbing moisture etc. the battens should not be embeded in the mortar. solution is to strip the wet verge, repair and extend the battens and install dry verge.

Eave trays

Untitled

• Alastairreid
• 22 Nov 2010
• 3

Dry verge.