Leak where the dormer roof trim meets the ridge tile

[Jo3]

Hi all,

I'm looking for advice on how to tackle this water leak and greatly appreciate any advice.

2 years ago we had a loft conversion built to make extra space for a new family member.
The work was done and before the job was finished we noticed several water stains on the inside of the ceiling, walls and around the velux windows. The builder said its normal and said it would settle. It happened again before the project was due to finish. The builder said he fixed it by putting silicone between the tiles and around the velux windows. But that didnt help and sadly he refused to fix it and left.

Going through insurance took a long time before they refused to help so we hired an independent roofer to visit and realised that the velux windows were installed without the apron. After the aprons were installed, the windows no longer leak however we have a water stain on the wall above where the dormer trim meets the ridge tile. The same roofer has visited as we thought it was the velux windows, however with a moisture metre the stains around the windows were dry and he thinks it's the silicone and cement bodge job between the dormer trim and the ridge tiles.

Is this normal? A second opinion would be greatly appreciated.

Photos attached.

Thanks,
Joe

 

[datarebal]

Well basically its a mess.
For a reliable job you need to strip the ridge off. Get the GRP detailing checked and corrected.
There should be no need to mortar anything around the velux. It appears back and sides are.
The silicon is someone grasping at straws. it should not be needed

 

[Jo3]

Thanks for the feedback Datarebal! It did seem odd that there was so much silicone if at all needed.

Sorry for the stupid question, but what do you mean by "get the GRP detailing checked and corrected"? Would you know where I can get more information? Im hoping once the rain clears up, I can strip the ridge tiles off and see whats under as the GRP may not be long enough. Would I need a flashing to put under the GRP edge and under the ridge tile just in case water is finding its way under the ridge tiles?
If I remove the mortar where the trim meets the ridge tile, how do i make sure it doesn't turn into a water trap? Something makes me wonder if the trim was cut too short and mortar was used to fill the gap?

Thanks heaps!
Joe

 

[palaceray]

The whole ridge area needs to be stripped of and sorted out properly.

Where does the flat roof discharge to ?

 

[Jo3]

Thanks Palaceray! The flat roof discharges to the other end of the dormer. See photo looks like a black dot, through the pipe down a gutter pipe.
Any advice on how to sort out the ridge?

Thanks

 

[palaceray]

The ridge needs to come off first. When the ridge is off you will probably need lead saddles formed between the flat roof and the tilling at the corners, the fat roof will probably need extra fibreglass over the lead saddle and ensure that the grp goes up an upstand under the ridge tiles before they are re bedded.

 

[Jo3]

Thanks Palaceray! Do you know if theres a T shaped ridge tile to put down instead of the mortar between the dormer trim and the ridge tile? Or should i use fibreglass to extend to the dormer trim to the ridge? How should the ridge tiles be held down? Im beginning to think I should leave this job for a pro roofer.

Thanks
Joe

 

[palaceray]

The grp does need to be taken up an upstand higher than the ridge tree.
A dry ridge system could be used as long as the grp is sorted out.
It does really want an experienced roofer.