Lead flashing

[andrewdumbell]

I have a single storey extension which when it rains heavily allows water into what was an exterior wall and is now the interior. The roof is a tiled roof and has lead flashing where it meets the exterior wall. The pitch of the roof however is quite shallow and I am wondering if during heavy rain and strong winds the water is being driven under the flashing. Can I silicone the bottom of the lead flashing to prevent this? Is there a recommended way of getting around this problem like maybe extending the width of the flashing. Any advice would be greatly appreciated.

 

[noseall]

we definitely need a photo for this one.

 

[justlead1]

Hi. If possible view the situation from inside the roof. This may tell you the cause of the problem, It may well be the flashing. However when additions are added to properties it is good practice to install a damp proof course at a point / course that corresponds with the top of the proposed lead flashing. The idea being any moisture that penetrates the brickwork / masonry above the DPC. will be stopped from passing down through the wall where it becomes an internal wall. Fitting such is often neglected owing to cost. Good Luck

 

[andrewdumbell]

we definitely need a photo for this one.

Thanks for your reply I will be on the roof this weekend and try taking a photo.

 

[andrewdumbell]

Hi. If possible view the situation from inside the roof. This may tell you the cause of the problem, It may well be the flashing. However when additions are added to properties it is good practice to install a damp proof course at a point / course that corresponds with the top of the proposed lead flashing. The idea being any moisture that penetrates the brickwork / masonry above the DPC. will be stopped from passing down through the wall where it becomes an internal wall. Fitting such is often neglected owing to cost. Good Luck

Thanks for your reply I'm hoping to seal the bottom of the lead flashing to the roof tiles in the hope that the water is coming up under the flashing and not down the exterior wall. Sticking the flashing to the tiles with silicone shouldn't cause any problems should it ?

 

[justlead1]

Hi. Probable not, there's enough give in silicon to allow thermal moment. Good luck

 

[kjacko]

Hi andrew.....
any progress on this, as i was about to post a new thread based on a very similar question.

And so to hijack your thread slightly ....

My 12.5° pitched roof has Redland tiles on it, and as yet doesn't have any lead flashing up. But one of the veluxes does leak in very rainy weather. My builder has suggested that because the vent pipe pops through the roof and hence there isn't a tile there at present then the angle of the rain on specific days runs down the liner and drips down the velux.

Moving forward in time, i have now moved the vent pipe and sealed the roof, so hopefully that stops the drip. This then leads on to andrews original question.
Could the angle of rain still get under the lead flashing and cause a leak on a 12.5° pitched roof? If so, shall i silicone down the bottom edge as suggested?

Thanks and sorry for the hijack.

 

[noseall]

Velux only guarantee their windows down to 15 degrees.

But, there could be issues with the fitting. Do the foam upstands fit snug to the tile underside? Were all the gap parameters adhered to?

A correctly fitted Velux rarely leaks.