What could this be? (New build)

Antony09

Hi guys
Hoping I can get some advice. So I've lived in a new build for two years the house is mortgaged to me. I'm the first owner etc. I've noticed in the past month or so the roof of my bedroom (which is an exterior wall) has began to get dark. Initially I thought it may be a shadow but over the past week three friends have commented and I've noticed it's happening on the same wall in the hallway and bathroom. If it's a problem I'm assuming it'll be covered on the ten year warranty but wondered if you guys here had any thoughts on what it could be?
For some reason the images won't embed?? Links below
https://ibb.co/mydopF
https://ibb.co/cfXsGv
https://ibb.co/jnEiOa
Thanks
Antony

Furts

Damp and probable condensation comes to mind. Likewise cold spots caused by cold bridging and poor, or absent, insulation. Knowing the roof detailing above would be needed to firm up any thoughts, but there is a flaw in all of this. Most likely you have only a two year builders defect cover, so you have no chance of the builder doing anything. This is because you are too late to notify them - you say you have been there for two years.

Two actions are possible - a goodwill investigation by the builder, or trying a structural defect/major damage claim against NHBC, or whoever has written the ten year warranty.

Try the builder first,in writing with copies of this. But be realistic and be humble. You have been given two years period of time to check and snag your home. An ample period of time, so if there is a defect then the builder could rightly respond that you have failed in your duty of care and been tardy. Consequently the builder may not be co-operative.

Fosterdog

If it's an external wall have you checked the guttering? Do you open windows regularly to air the place? Are they the rooms you use most often?

Doozergirl

Pictures of the outside of that wall would be good.

Any trees nearby? Blocked guttering springs to mind.

Antony09

Cheers for the replies really appreciated.

Yes the hallway window is open a lot as is the bathroom and my bedroom. I don't air any clothes in there or anything like that.

Here are a few pictures of the exterior wall

https://ibb.co/eUgVKF
https://ibb.co/hisRta
https://ibb.co/kv5qKF

No trees nearby either...

Silvertabby

Does it feel damp?

Doozergirl

Is that staining on the soffit near the wall too?

I'd say it's definitely something to do with the guttering. Spilling over towards the inside and then running along the soffits.

Antony09

If the softbit is the white bit I've just leant out the hallway window and felt it. Stone dry as is the wall even after all this rain we've had!

Doozergirl

Soffit. I can see it's uPVC so it wouldn't show anything on the underside if there's a leak.

I'm sure it's not a coincidence that this is appearing in a line across your upstairs walls where there's guttering on the other side.

If it's only been going on for a month then there may not be any evidence on the outside wall when it's not raining, especially if it gets the light.

The gutter needs checking when it's actually raining.

Have you touched the areas inside? Cold? Clammy?

If you're outside the original two year defect period then I doubt it's something that your NHBC cover will touch. They don't seem to cover much at all. Get it sorted quickly and I don't think it will be an expensive fix.

Furts

Good to see the photos. You have a conventional roof and soffit detail. Interesting window venting detail too - has this been checked for connection and integrity? Plus what trickle vent/opening detail do you have and what control is there here?

It is unlikely to be a gutter leak, or blockage. The reason being the gutter is fixed way past your outer brickwork, whilst your marks are on your inner face of a cavity wall. I still sway towards my earlier comments - check cold bridging, and lack of insulation - been there before on this one!

Lifestyle also plays a part, so tehe builder could blame excessive moisture levels within the home. Whilst this may be boll--ks, it is a stock reply from builders and NHBC, so forewarned is fore armed.

Best of luck, and keep us posted.

vw100

I have seen this sort of thing before, if not slightly worse. I suspect it lack of insulation above the ceiling or some cold spots.


I think if you got some house hold cleaner and gave it a wipe you should be able to remove some of it.


NHBC warranty I doubt they will do anything and blame lifestyle type of issue.