Water Marks Advice

[jonnyollet]

Hi all,

I am looking for some advice and what can be done. Back at the start of 2020, we had our loft converted. In the recent cold weather, we have seen water marks coming through...

Looking back through my photos of the renovation, these marks seem to line up with where the breaks in the insulation foam are...

From what I have read on these forums, there needs to be a vapour barrier or the insulation needs to be taped up at the seams. However, it looks like this has not been done.
During the build (early 2021), we did notice some water marks and noted this to our builder... this was also during a cold snap (Jan 21).

I guess this is ice build up on the slate nails, which when melts, the water runs down the insulation. My builder is now ignoring our calls as we feel he did not complete the job properly.
We are a bit stuck as to what to do next. From the pictures, has our builder missed something that is resulting in these marks?
Many thanks in advance

 

[catlad]

Lots of gaps, and I can't see any sign of a vapour barrier.

 

[RandomGrinch]

Looking back through my photos of the renovation, these marks seem to line up with where the breaks in the insulation foam are...

Yes, it looks to me as if the water marks are along the plasterboard joints.

I wonder if you can confirm, but it looks to me (from a massive zoom), that the plasterboard is foil-backed and insulated?
In which case, there is a token VCL, but it wouldn't be perfect.

 

[flameport]

where the breaks in the insulation foam are...

There shouldn't be any 'breaks'.
Should have been a continuous layer of thick insulation with no gaps, all seams taped so that it is airtight, with the plasterboard applied directly onto that with no gap between insulation and plasterboard either.

Photos show random pieces of PIR insulation shoved in with various gaps, plasterboard with a thin layer of insulation on the back and a massive gap between that and the rest of the roof.
Completely wrong, and the only fix for that is to remove it all and start again.

 

[harrythefurrysquid]

There shouldn't be any 'breaks'.
Should have been a continuous layer of thick insulation with no gaps, all seams taped so that it is airtight, with the plasterboard applied directly onto that with no gap between insulation and plasterboard either.

Photos show random pieces of PIR insulation shoved in with various gaps, plasterboard with a thin layer of insulation on the back and a massive gap between that and the rest of the roof.
Completely wrong, and the only fix for that is to remove it all and start again.

How do you even approach that with the builder, assuming it's still under warranty?

If the builder stops communicating, as with the OP, what do you do next? Is there any sort of body who will give an impartial assessment of the quality of the build? Do you sue the builder?

 

[RandomGrinch]

Apart from the poor work, there is also an element of unluckiness/poor planning!

It just so happens that the joints of the insulated plasterboards:

Match up perfectly with the very poor fitting joints in the underlying insulation boards (if they have been fitted similarly to the other side - highly likely).

Which is definitely asking for trouble