How to finish lead flashing corner

[happyolly]

Hi hope you can help please.
Is there a simple guide out there for lead flashing, I've got to do a straight line of about 4.5m onto Forticrete Centurion tiles laid at 12 or 13 degrees.

I've read I should use 1.5m strips but the questions outstanding are.......
How much overlap?
Lead bungs every 30cm?
How deep into the wall?

Ok Ok...I'm sure the answers to those are a quick search away but the next bit I'm stumped on.
How do I finish the corners please?




Thanks Olly

 

[cotswoldbuilders]

150mm over lap
30mm deep chase
Extend the lead over edge of tiles about 100mm then dress/boss the side down tight to edge of verge.

 

[ree]

I hope you dont mind but I dont understand your post. Where do you want to flash?

Do you mean to flash the lower roof tile into the abutting wall?

As a matter of interest, the verge pointing is way too deep for my liking - its about 200mm to 225mm deep altogether.
Or maybe thats a regional detailing?

 

[happyolly]

The weather boarded lean-to is what we've just built. If you look very carefully you can see the cut I've made into the mortar above the top tile.

The verge pointing of the new build can't be any smaller if you put the battens on top of the under cloaking. It would be even deeper if we'd counter battened, instead the laths sit on lead pads to lift them off the sarkin roof - In hindsight, for the few mm of extra upstand of lead it gives it wasn't worth it.

The really deep stuff on the other building is a bit OTT but it's a trick of the angle I took the picture at that's making it look so substantial.

Do you know of any pictures of what I should be aiming for on the lead corner detail please?

 

[ree]

Try: leadsheet.co.uk ... (the handbook) its the lead sheet association. If you see any pics of what you want give us a shout on here for how to boss and bend it.

 

[happyolly]

Right, so from that lead site:
min 25mm into the wall
450mm between bungs
1500mm pieces of flashing
100mm overlap
75mm upstand (actually that will be dictated by the cut in the mortar but it won't be much less than this)
Blimey...looks like they're suggesting a lap of about 350mm. Stuff that! I think the roll we have is about the wide in total.

but I can't find any pictures about the corners

 

[Alastairreid]

This any good?

http://www.youtube.com/watch?v=R-vrSq-x40Y

 

[happyolly]

...yep thanks. 8:20 shows an example.
The tip at 8:05 about folding a corner over the different sections is good. I won't be using straps.
I'll try to get my bungs in a bit further than some of his too so they get a reasonable cover of pointing.

 

[yorkie1969]

Hi there,

Be sure to get the lead 25mm into the chase. this is important to stop the lead from moving and coming out of the joint and stops leaks via capillary action.
I would strongly suggest that you point it with a lead sealant as opposed to mortar. I have never seen sealant come out of a chase but have seen mortar come out hundreds of times.
The dovetail clip on the video at 8.05 is a good idea, however, the gentleman has got it the wrong way round which is a small but common misconception. Cut it the opposite way so that the underlap goes over the overlap.

Regards.

 

[happyolly]

Hi there,
Be sure to get the lead 25mm into the chase. this is important to stop the lead from moving and coming out of the joint and stops leaks via capillary action.

Will do, funnily enough the chap in the video suggests you can use less.

The dovetail clip on the video at 8.05 is a good idea, however, the gentleman has got it the wrong way round which is a small but common misconception. Cut it the opposite way so that the underlap goes over the overlap.

It does appear to show a piece of the under lead being bent up over the the top lead. I can't think of a different way you'd be able to (or would want to) do it.

Thanks Olly

 

[yorkie1969]

Hello again,

I believe the gentleman in the video to be a roofer as opposed to a leadworker. His videos are great, but, as to the finer points of leadwork I would tend to trust a leadworker or indeed the 'Lead Sheet Association' recommendations. Please see the link below

http://www.leadsheet.co.uk/fixing-of-lead-sheet-flashings-fixings-to-abutment-walls

With regards to the dovetail clip, he has cut the clip from the left hand open side of the lap and bent it backwards. The trick is to cut from the right hand side there actually underneath the overlap, peel it back to the left and then over the top to the right. Then you don't have a little triangle missing.

Kind Regards,

Mark.

 

[happyolly]

Ahhh....got it....thanks I'll do it that way.
Thanks Olly