Just need to finish my small lean to style porch tiled roof and have acquired some 300mm width lead flashing to go under the house wall hung tiles and over those on the angled porch roof. Only prob is there are 2-3 pieces I'd need to join together but they were free as opposed to £50 for a new roll from a builders merchant I can't complain.

Question is whats the best way of joining/securing/overlapping etc the lead flashing so the water can't ingress?

(It is only a small external porch and the roof is felted underneath the battening).

cheers,

Ned.

For a butt joint I would do this then tamp it down with a bit of wood and a mallet to tighten it up before taking it onto the roof.



lead flash

Or the proper way is to weld it!

i use a tube of leadmate

http://www.cglass.co.uk/product.php?productid=17610

think you can get it from screwfix.

http://www.screwfix.com/search.do?_dyncharset=UTF-8&fh_search=lead+mate

no need for worming the joints(thats hooking one over the other) unless you're in an exposed area, just make sure you have 150mm lap on the joint and dress down neatly to the tiles you shouldn't have more than 1.5 m of lead in one piece to allow for expansion HTH Roger

I've seen all of the methods above.
I have also seen lead dressed expertly into shapes you wouldn't believe.

However, I once worked with a guy whoc could gas weld lead and leave a finish that was '907' good.

Doesn't need huge levels of heat either.

Weld it - you know you want to.

I agree with that, just make sure the edge of the flashing where it overlaps is facing away from the prevailing wind, not towards it it, if thats possible,

I would still go for worming it, its not really that much effort and its going to cope with ANY conditions.

But thats just me.

When i get the chance i just love over engineering things lol

Lead welding takes a lot more skill than you might think.
One second it's solid, the next it's running all over the shop.
They used to use oxy/hydrogen torches to do it where I used to work.

Overlay 150mm and it will be fine.

My builder uses silicone and after wedging it in the raked out morter, fills that with silicone as well.

Pat...

I use oxy/acetylene for lead welding. As has all ready been stated lead shouldnt be fitted in lengths over 1.5m. Expansion/contraction will split it over time.

Silicone around lead is not a good idea, some silicones, (acytoxy), can damage the it. There are propriety sealants developed especially for fixing and sealing lead and these should be used. They are also much better for pointing in as morter can and does fall out again due to expansion/contraction.

I use oxy/acetylene for lead welding. As has all ready been stated lead shouldnt be fitted in lengths over 1.5m. Expansion/contraction will split it over time.

Silicone around lead is not a good idea, some silicones, (acytoxy), can damage it. There are propriety sealants developed especially for fixing and sealing lead and these should be used. They are also much better for pointing in as morter can and does fall out again due to expansion/contraction.

Thanks for all the tips. As it's only a porch and in a corner I think I'll just overlap it away from the elements and see if the black roofing gunk I bought a while back is suitable for use on lead.

cheers all,

Ned.

Don't put roof seal on it ned, it turns lead brittle. Just flatten it down well with a piece of 3x2 and a hammer.