Leaking Roof on Bay window

tuggy12

Hi,
Looking for some help to solve a problem of water leaking through the roof of a flat lead topped bay window.
The house is 70 years old and the lead top and flashing is the original fitted.
Have lived in the house for many years without problem and then suddenly during heavy rain water started dripping from the ceiling inside.
I've checked the lead and flashing and it looks sound and also the rendered wall above the bay is in good condition with no visible cracks.
Is it possible that the lead has become porous in some way?
Would it be worth covering the lead with bitumen paint?
Any ideas would be appreciated.

latecomer

Have you checked to see if there a problem above the lead and the water is running down underneath?

tuggy12

latecomer wrote: »

Have you checked to see if there a problem above the lead and the water is running down underneath?

Yes, the flat lead sheet is folded up the wall about 4" and the flashing is pointed into the wall above that and completely covers the 4" upfold.
The pointing of the flashing is good with no cracks.

davethetaller

tuggy12 wrote: »

Hi,
Looking for some help to solve a problem of water leaking through the roof of a flat lead topped bay window.
The house is 70 years old and the lead top and flashing is the original fitted.
Have lived in the house for many years without problem and then suddenly during heavy rain water started dripping from the ceiling inside.
I've checked the lead and flashing and it looks sound and also the rendered wall above the bay is in good condition with no visible cracks.
Is it possible that the lead has become porous in some way?
Would it be worth covering the lead with bitumen paint?
Any ideas would be appreciated.

I suppose that with a house that is 70 years old, there is no cavity wall.

So water is not running down from well above the window.

One less avenue to explore!

tuggy12

davethetaller wrote: »

I suppose that with a house that is 70 years old, there is no cavity wall.

So water is not running down from well above the window.

One less avenue to explore!

Yes it's a cavity wall and I'd wondered if water could be running down inside the cavity but there is an upstairs window that runs across the full width of the bay window below with about 4ft distance between the two.
So the only way I could see water getting into the cavity between the upstairs window and the top of the bay would be through the wall but the wall is rendered and in good condition.

thebaldwindowfitter

were is it coming in near the window or quite far away ie under the wall above?i have known water dripping down cavity if the window above hasnt been sealed properly.the lead hasnt been nailed down has it with cloat nails

tuggy12

a6windows wrote: »

were is it coming in near the window or quite far away ie under the wall above?i have known water dripping down cavity if the window above hasnt been sealed properly.the lead hasnt been nailed down has it with cloat nails

Difficult to pinpont exactly where it's coming in as the water spreads across the plaster before finally dripping through but it drips from under the cavity wall area.
The lead and flashing is not nailed. The lead sheet is folded tightly round the top of the wooden bay frame and the flashing is soundly pointed into the wall.

The window above the bay is a 7ft wide upvc frame which has been well sealed with silicone.

This problem has me totally puzzled, thats why I was wondering if the lead sheet had become porous with age?

BargainGalore

We had this problem 2 years ago despite not finding the leak we had the whole roof redone with waterproofing paint, still it got through, so had the roof replaced with EPDM

Sometimes its very hard to trace where water gets in

tuggy12

BargainGalore wrote: »

We had this problem 2 years ago despite not finding the leak we had the whole roof redone with waterproofing paint, still it got through, so had the roof replaced with EPDM

Sometimes its very hard to trace where water gets in

Thanks.
Was your roof originally lead or felt?

thebaldwindowfitter

tuggy12 wrote: »

Difficult to pinpont exactly where it's coming in as the water spreads across the plaster before finally dripping through but it drips from under the cavity wall area.

The window above the bay is a 7ft wide upvc frame which has been well sealed with silicone.

This problem has me totally puzzled, thats why I was wondering if the lead sheet had become porous with age?

the window may be well sealed but if it has a cill on and the edges not sealed under the frame this could cause water to drip down into cavity .lead doesnt become porous as such

tuggy12

a6windows wrote: »

the window may be well sealed but if it has a cill on and the edges not sealed under the frame this could cause water to drip down into cavity .lead doesnt become porous as such

I'm not sure I understand you here.

The upper upvc window frame is sealed with silicone between the outsides of the frame and the brickwork - there's a good 10mm bead of silicone all round including under the cill.