Wind driven leak?

[david nixon]

Hi
I have a lean to rosemary tiled roof on the kitchen...approx 10ft long, 3ft high
Its fairly shallow - maybe 30 degrees and has been redone last year by my a local roofer who replaced the tiles, added new batons, new DPM and flashing.

Up to now its been fine but we have been battered by westerly winds the past couple of days and consequently the rain has been coming in the kitchen.
I cut a hole in the kitchen ceiling as the water damage was pretty bad so I could take a look and stop it spreading.

The water is coming in on a 2 foot section of the roof and the water appears to be trickling down the exterior cavity wall on both sides.
The DPM is bone dry throughout as is the rest of the roof apart from this one section.

I'm thinking its possibly rain being driven under the flashing but can't figure out why it would be only in one section.
I'd go back to the lad who fixed it but he's in a bad way with covid.

I've done the usual googling about lead sealants etc but would welcome some real advice

I got up on the roof this morning and lifted the lead flashing a couple of mm and water was released from under the flashing

Any advice would be most welcome...

 

[datarebal]

The pitch is nowhere near 30 degrees , looks less than 15.
It will almost certainly leak on to the underlay.
Doesn't look enough cover on the flashing over the tiles either.
Water under the leading edge of the lead is common .
Your best bet is strip a few tiles out to see if the underlay is holed.
End of day though, it's destined to fail

 

[david nixon]

Thanks for coming back to me...I can confirm that the underlay is not holed in any way.
Would it be reasonable to assume the water is being driven up under the flashing?

 

[datarebal]

It could drive under the flashing . It looks like there isn't much cover anyway. That aside, the underlay should turn up the wall.
Then if any water blew up under the flashing it would land on the underlay .

 

[catlad]

Probably soaking through the bricks.

 

[mrrusty]

I see no sign of a cavity tray or any weep holes. Do you know if there is one? If the extension is original it is quite possible the original lead tray continued outwards to become a flashing (just like on my house). If the old "flashing" was cut off and the new inserted above, the old lead cavity tray now discharges underneath the flashing....

 

[david nixon]

There is a lead cavity tray that I can see from looking up the cavity from the hole in the kitchen

 

[mrrusty]

There is a lead cavity tray that I can see from looking up the cavity from the hole in the kitchen

In which case, if the roof flashing is new, you should be able to see the old lead cavity tray ABOVE the new flashing (or at least some weep vents). If it's underneath and the new flashing has been let into the wall higher up, then it could be the cause of the leak...