Roof Leak - Strange one (pics attached)

Krav

Hello,

I had a new pitched roof fitted in 2010 at the back of a semi detached 3 bed house. The problem is that there has always been some damp on the wall where the roof is at its highest point. I got another builder to have a look a year ago and he replaced the flashing and all seemed fine until a few days ago when the dampness re-appeared. It seems odd as we cannot see any gaps looking at the roof. The first builder thought it was the exposed wall at the top and dabbed some mortar (you can tell from the pics). Does anyone know what it may be? I have links to the bedroom wall and the roof



The water comes in at the top of the roof in the picture below:

justjohn

hard too see from photo ...can you take a better photo of the old to new roof join...eg whats the new roof joined too?

i am not a roofer,however if i understand you correctly. you have a sloped roof that joins on too the building. the roof is not old and internaly its always been damp. my first assumption is the leak is from the join not the new roof.

As you have found many roofers are using guess work.....sometime it works sometimes it does not.

keystone

Sure its damp? How was that wall treated before it was painted? Is there residual wallpaper paste behind the dark patches?

But the condition of the interface between the wall and the box suggests that there is water in there. That really nice box is providing a really nice waterway and the emergence of the water in the locations you can see doesn't mean its getting in there at that point. Water can travel a long distance undetected before it emerges.

Have you suspected the pipework which I have a feeling may well be in the box? It may not be a leak either it could be condensation on cold pipe dropping down.

So not so simple but as you already have significant repair work to do to the box I'd be looking at removing part of that first for further detective work.

Cheers

justjohn

keystone wrote: »

But the condition of the interface between the wall and the box suggests that there is water in there. That really nice box is providing a really nice waterway and the emergence of the water in the locations you can see doesn't mean its getting in there at that point. Water can travel a long distance undetected before it emerges.

box???????????????

do you mean the cement ridge or wall at the top of the pitch?

i was insure what that was....depending on what it is i would have been inclined to go over the whole lot with lead. i would assume that ther is some lead flashing there however water could be comming in from top of that ridge or from a gully at the other side if there is one.

toejumper

we have the same problem for the 3 years and just discovered its an air vent, water was going into a piece of guttering then shooting out straight into the air vent. the rain water has actually traveled 10 feet away from were the air vent is situated and has damaged a ceiling in the utility room. i would take a look at that air vent on the roof,

justjohn

toejumper wrote: »

we have the same problem for the 3 years and just discovered its an air vent, water was going into a piece of guttering then shooting out straight into the air vent. the rain water has actually traveled 10 feet away from were the air vent is situated and has damaged a ceiling in the utility room. i would take a look at that air vent on the roof,

air vent is over a foot down and damp internaly looks like its at the joint.

so looks like its either at the joint or before the joint

keystone

justjohn wrote: »

box???????????????

Yes - inside the bedroom.

Cheers

justjohn

keystone wrote: »

Yes - inside the bedroom.

Cheers

Ah you recon there could be a pipe in there?

maybe lol bit messy too box a pipe in like that lol

keystone

justjohn wrote: »

Ah you recon there could be a pipe in there?

maybe lol bit messy too box a pipe in like that lol

Well yes could be but there is something in there otherwise no need for the box. It could be just covering up a piece of exposed masonry which could equally be suffering from condensation in an enclosed space. I'd have the bottom off the box for starters for the internal detective work tbh. Bearing in mind this problem has existed since before the roof was done I'm not sure pottering about on the roof is the correct solution yet.

Cheers

Krav

Hi All

Thanks for taking the time to reply. The horizontal "box" you see in the bedroom is actually the wall plate which the roof rafters are fitted similar to this pic (this is not the actual roof, just a similarlook). There was no false ceiling fitted to maximise space.

There is one tile which I think is an air vent but that was fitted after the 2nd builder came and did the flashing - so it was leaking without an air vent.

The leak is only at the joint between the party wall and the wall plate, but with flashing covering it and some mortar, it is guess work as everyone just scratches their head when having a look.

Library pictures - both are not actual roof shown for illustration purposes only ->

Search for "Rear wall plate" here
http://www.ultimatehandyman.co.uk/roofing/build-pitch-roof.htm

keystone

OK well that at least removes those possibilities I've mentioned from consideration then.

UHM doesn't like you using their piccies BTW.

Cheers