DIY Doctor UK DIY Forums

Hi,

I'm quite new to DIY but having had success fixing rotten floor joists I'm keen to get onto the next job!

I've noticed that the rear roof (through which we're planning to put a flue in order to move the boiler) is sagging slightly in the middle, and the cement/mortar above that section is coming free, exposing the (what I guess should be) internal side of the lead lining. I think that water might be getting in and has compromised the rafters, hence the dip in the roof.

I have read a little about "buttering up" of roof ridges and it being a no-no, so I'm not sure if this was just a bodge job at some point in the past and if I just chip out all of the old/loose cement/mortar and replace, I'd just be repeating a shoddy bit of work all over again!

Would anyone be able to tell me what the proper fix for this would be? Maybe the steps I should take to fix it properly?

Any help would be really appreciated! What I lack in experience I make up for in enthusiasm... but I'm very aware I actually need to learn what the hell I'm doing eh!

Pics are here, sorry for the external link... DIYDoctor only lets me upload 500k pics which just aren't big enough!

http://www.matt-k.com/downloads/house/roof/roof1.jpg
http://www.matt-k.com/downloads/house/roof/roof2.jpg

Cheers, Matt

Hi. I was a bit confused for a bit. The pictures show a ridge abutment, not a ridge line and the roof is effectuvely a lean to roof.

The Render needs to be taken from the abutment wall with a hammer and bolster or electric chisel.

The flashing needs to be removed and the chase cut out to at least 35mm deep. The lead needs to be reinserted and wedged into the chase with small offcuts of lead folded over on themselves and banged into the chase with a bolster to fully trap the lead inside the chase. The chase needs then to be repointed fully. Then the render needs to be redone (see our rendering page.

The rafters in the roof need to be checked for wet and dry rot (see our pages on this also) and treated if necessary. They also clearly need to be strengthened by the addition of roof timbers bolted to the existing.

While it is possible for this job to be done DIY it is a tricky undertaking for someone with no experience so please do it in small sections, overlapping the lead by at least 150mm in the chase as you move along the wall.

Good luck and please do let us know how you get on.