# pointing lead flashing



## Joe Shmoe (16 Nov 2012)

Hi, 

I've just fixed some lead flashing along a lean towards roof that joins an existing wall. 

Question is, do I fill the pointing gap with mortar or a sealant, as I always thought it was mortar but seen some YouTube videos where a sealant is used? 

Cheers


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## Rob Platt (16 Nov 2012)

Sealant is good if there is only a small gap. Sand cement mortar type mix pointing needs to be sufficient size wise to give it strength otherwise it will dry but wont go hard . Either will do if the conditions are right. HTH 
all the best
rob


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## Dibs-h (16 Nov 2012)

Leadmate b y Everbuild - http://www.everbuild.co.uk/lead-mate

makes it far easier and probably will outlast mortar. and don't forget to put patination oil on the lead!

HIH

Dibs


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## Eric The Viking (16 Nov 2012)

+1 for Leadmate if the gap is thin.

There is a lead products association web site somewhere...

Did you wedge it in the traditional style, with rolled-up strips of lead hammered in on top of the flashing?? 

I use a stiff (heavy on the cement) mix, with some coarse sand/very fine gravel added. The coarse sand gives it better weather resistance -- you're supposed to do that with roof ridges and stacks. If it's not very exposed ordinary mortar may do, but it's only gap filling - the lead wedges are actually holding the flashing in place. 

If, like me you use an angle grinder to open the slot, instead of a bolster or thin chisel, it's probably wise to brush it out well with a paintbrush and paint it with PVA before re-pointing. The PVA helps the cement bond to the brickwork, and ties up the dust so that it doesn't make the mortar loose. I use a spray bottle usually, as it's quick and gets right to the back. I believe PVA makes it a bit more frostproof, too, while it's going off.

I've done our stacks' step flashings that way (40ft up, house on a fairly exposed hill), and the older one is still fine, 16 years on.

HTH,

E.


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## Joe Shmoe (16 Nov 2012)

Cheers for all the advice guys.

I had to use an angle grinder to cut along the wall as it had been rendered, made quite a large gap so will use mortar as per Eric. I banged in wedges of lead to hold it in place, so fingers crossed it will all be okay. As with most things, it's not that hard doing it, just gotta know what to do lol. I have the oil too, cheers dibs.


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## Lons (16 Nov 2012)

This is a useful guide to leadwork

http://www.calderlead.co.uk/wp-content/ ... adwork.pdf

Bob


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## Paul Hannaby (17 Nov 2012)

When I did some leadwork I bought some stainless steel spring clips to hold the lead in and then used lead mastic in a mastic gon to fill the slot.
I also found out that the lengths of lead rolls are approximate as they are sold by weight so I got half way through the job and had to buy another roll for the sake of a few inches!


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## devonwoody (18 Nov 2012)

Paul Hannaby":3vrfo8wp said:


> When I did some leadwork I bought some stainless steel spring clips to hold the lead in and then used lead mastic in a mastic gon to fill the slot.
> I also found out that the lengths of lead rolls are approximate as they are sold by weight so I got half way through the job and had to buy another roll for the sake of a few inches!




Paul dont worry about the surplus, it keeps, increases in value and might double its market value over the next 7 years. :wink:


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## Lons (18 Nov 2012)

Paul Hannaby":6ug9eb20 said:


> When I did some leadwork I bought some stainless steel spring clips to hold the lead in and then used lead mastic in a mastic gon to fill the slot.
> I also found out that the lengths of lead rolls are approximate as they are sold by weight so I got half way through the job and had to buy another roll for the sake of a few inches!



I use the clips as well - have done for several years and they don't loosen up like the traditional folded lead wedges do. these are what I buy http://www.toolstation.com/shop/p91107

I have never had a problem with lengths of lead Paul. I buy in various widths (usually from Jewsons) but in specific lengths It is sold by weight but then the cost is reflected accordingly so if you buy a length of 250mm x 10m code 4, that's what you should get and you are charged at £? per kilo.

if you ordered say a 6 metre length and didn't get that then you've been short changed.

Bob


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