Loft conversion leak

[TomTom123]

I've copleted my own loft conversion. No steel beam needed as middle supporting walls.

Prblem::: after 3 months damp patch along back purloin appeared all along it.

Solutiion:::: Guy who put in windows for me thought it might be windows that but it wasn't so he thought maybe roof vents. He took two above purloin ( the big roof supporting beam?) out we waited it seemed to have stopped. About 12 to 9 months later on a frosty night there was a small leak and when I looked the dampp patches were back.
Roofer says tiles are fine.
I think I shouild take off piaster board and insulation and have a look at membrane or some kind of stoppage; roofer he "NO!" and I do not want to.

Poss solution Get roofer to look at mebrane underneath by lifting tiles.
I DO NOT KNOW WHat TO DO

Any ideas please? am At total loss especially as it seemed to go away and come back on a frosty night.

I can only think that the vapor barrier has been forgot or the insulation has blocked something
HAS ANYBODY HAD A SIMIIAR EXPERIENCE

Please let me know
THANKS

Tom Deegan

 

[Alastairreid]

Quite difficult to decipher your post!
Reading between the lines you have obvious condensation issues, and to give an answer you will have to tell us what the detail is in the roof, insulation, vapour barrier etc.

 

[TomTom123]

I have done everything to do with regs. The thick insulation, silver backed its name escapes me now, along with vapour barrier and 12mm plaster board. The only thing I can think of is that I may have missed out the vapour barrier in one part because it is alright on the other side. Could this do it or could I have damaged the membrane of the roof?
Could it be that I have pushed the insulation so that it pushes against the tiles and is causing a blokage? i'd love to have some guidance on this.
Thank you for reply

 

[freddiemercurystwin]

Is there a gap between the membrane and the insulation, is there a membrane at all, if there is, is it felt or breathable, is the gap vented at the eaves and the ridge? Questions questions ....

As mentioned your first post is not very clear.

 

[TomTom123]

Thanks for interest sorry about confusing reply.
There is a gap between membrane and insulation.
i wonder if that gap has been broached when putting insulation in and is this causing the "leak".
There are vents about six either side.
There is a vapour barrier but have I inadvertently left it out and could this have caused the problemt. It is only happening on one side and very small but very worrying.
The membrane I believe is breathable.

 

[datarebal]

which side of the roof... North ? South ? etc