Recent renovation with ceiling water stains under GRP roof

slipstream

We got a major house renovation over 2 years ago which required planning permission, was managed by our Architect and involved a standard architectural contract with the builder.

We withheld 5% of payments until the builder returned and fixed up snags after 12 months or so.

Recently we have noticed water stains (image attached) in the center of our living room ceiling. The stains appeared within 24hrs of heavy rain and above the ceiling is a large GRP flat roof with no obvious sign of damage.

We got along fairly well with the builder and I've contacted him about this problem but he has not got back to me yet.

What I was looking for help on was:
1) What would you guys recommend as our next steps?
2) Are we on our own resolving this problem? should the builder be helping us? could he be in any way liable?

Thanks,

Slip

tradesman

You need the builder to come out asap to check the problem. If he is slow or not returning your calls it doesn't look good. Do you know if there are any pipes in the ceiling void? Could be a leaking joint. Keep a check on the stain, if it drys out then gets damp when it rains (or shortly after) then it is definitely a fault with the roof or where the roof attaches to the house / roof. Keep ringing the builder, that's the only way you will get a response. If he is not interested you need to get onto a consulting engineer to assist you.

jmBuildExt

Talk to your architect.
Check your tendering docs.
Architects often insist that main contractor get in a specialist roofing contractor that will gurantee the roof for a certain period of time.
It may be another route to getting it sorted out.

slipstream

Thanks for getting back to me.

tradesman wrote: »

Do you know if there are any pipes in the ceiling void? Could be a leaking joint.

There are no pipes above the stains but there is an air duct which is connected to the outlet in the pic. However this is a semi-rigid one-piece duct so I doubt its related to the stains.

I'll try to post a picture of the structure above the leak during the build. looking at the tender doc and pictures I think there is a service cavity then a vapour/air tightness barrier taped to a long steel beam, then rafters with spray foam insulation, then kingspan and OSB followed by the GRP.

tradesman wrote: »

If he is not interested you need to get onto a consulting engineer to assist you.

I guess sections of ceiling plasterboard needs to be removed when the area is wet to work out where the water is coming from. What kind of engineer should I be looking for?

jmBuildExt wrote: »

Architects often insist that main contractor get in a specialist roofing contractor that will gurantee the roof for a certain period of time. It may be another route to getting it sorted out.

I've looked at the tender docs and unfortunately, I do not see any mention of roof guarantees.

If we have to spend thousands getting to the bottom of the water stains and probable leak, could the builder be liable in any way or is he in the clear once the snags period has elapsed.

slipstream

slipstream wrote: »

I'll try to post a picture of the structure above the leak during the build. looking at the tender doc and pictures I think there is a service cavity then a vapour/air tightness barrier taped to a long steel beam, then rafters with spray foam insulation, then kingspan and OSB followed by the GRP.

I've attached a picture of the water stained area during the build and marked thr rough location of the stains.

Could water be collecting on top of the membrane and then coming through a nailhole or where it is taped?

jmBuildExt

The problem with water is it could have run along anything before it dripped and formed a puddle big enough to soak through. So the problem isnt always directly above.

Have you tried talking to your architect to see can he get the builders back.
Not saying its his fault, but since he was managing it he should be at least able to tell you what course of action to take.

tradesman

I suggest you start by ringing the builder & ask him will he come out to have a look at the leak as he has knowledge of the way the roof was constructed. It may not be his fault. If he is a "proper" builder he would want to come out to see if it is a problem on his side so he could rectify it for his client or even could be a new source of extra paying work for him!

If no joy then do you know any roofer friends?

Get onto an insurance assessor to handle a potential claim for you. It would mean removing the ceiling anyway as the plasterboard has probably perished.

In your second pic there looks to be daylight showing, Is this where the new roof abuts the old? That junction could be the problem