"keith_765" wrote in message
...

"Ali Mac" wrote in message
...
Got a leak in my valley (or should that be leek?). And I'm pretty sure
I've
found the cause -a small 10 cm horizontal tear across the final sheet. I
think it's the cause because some silicon sealant roughly squished in on
the
end of a stick leaning out of my velux does reduce the drip in the attic.
So
on the next dry day if I stick a length of flash banding down the valley
will this stick for a few weeks so that I can plan my next move? Or is
there
some better solution that someone could suggest?

Alistair in very rainy Manchester

Flashband will stick provided that you use a primer first. Leadmate will
seal the split on its own, just spread on 25mm each side and build a ridge
over the split. smooth the edges with a wet finger.

Here's the correct way. If you can get on the roof, remove the slates or
tiles on both sides of the valley where the split is. Cut the split all
the
way across, lift up the top piece of lead and insert a new piece the same
width across. pushing the new piece about 150mm or 6" up under and lapping
150mm or 6" down over the lower half. Nail the new piece with 2 copper
nail
each side at the top, fold down the old lead and dress flat, replace the
slates or tiles. Best if you number the slates or tiles as you take the
out.
this will make it easier to replace in the correct order. Code 4 lead
should be used.


Thanks all for great advice. I'll lead patch just because I've got lead and
leadmate and it sounds more solid, and then tackle the insert next summer.

As a matter of interest, the section of valley that split was half way down
a continuous 3m run and I've been reading loads of posts recently about 1.5m
being the optimum max length for flashing and so on. On the basis that the
same is true for lead in a valley, there is an example on what can go wrong.
Roof relaid about 15 years ago (slate, mortared ridge tiles, lead flashing
etc) and is starting to need some TLC, which I think is way to soon.

Alistair