Roof/velux leak

[Caley King]

Hello All, I'm a long time lurker and first time poster.

I built an extension last year and installed velux and had no problems until very recently.

We've had two good downpours, one was extensive a couple of weeks ago and a deluge this morning. On both occasions there is a damp patch on the ceiling plaster at the reveal but not in the actual reveal which is odd.

It's strange that there has been no leaks until now either. I've been and removed the tiles and the felt is dry as well as the flashing kit etc, insulation collar and gutter. It's also a recessed edz for ref.

I also installed three other veluxes in the same roof identically with no leaks or damp patches. I'm at a loss what to do next if I'm honest so any advice would be appreciated. Attached are a couple of pics for visual reference.

I thought it might have been capillary a couple of weeks ago as it was super windy but that theory doesn't stack up as this morning was a deluge with no wind.

Cheers

 

[KenGMac]

Caley King, good evening.

Can I suggest you check externally for any debris / leaves Etc. which has built up anywhere around the Velux flashing and the adjacent roof tiles.

Ken.

 

[CJRatch]

Did you fit the Velux transverse drainage gutter? As the leaks from the top water may have passed your tiles onto the membrane and without the gutter to direct rain around the window it's running down the top of the Velux opening in the timbers.

If the tiling is done right rain shouldn't pass to begin with the gutter is belt and braces. I'd look at the tiles above the leaking Velux.

 

[Caley King]

Thanks for the rapid responses gents. I can confirm I installed a tranverse gutter system and there is no built up debris. Have a look at the attached pic

 

[datarebal]

Check the back gutter again with instructions to hand

 

[catlad]

Yep! back gutters no on correctly.

 

[Paul Saunders]

Hi did you get to the bottom of your leak? I have similar

thanks