Pointing outside wall...

cyclonebri1

It looks as if the original was sat on mortar and then mortar'd over ie, it's in the centre of the joint. I would insert the lead above the existing dpc and bend it to the lower edge, wedge it in place with rolled and hammered flat bits of scrap lead evry couple of feet. These will be lost in the joint.

IE the lead will sit over the existing DPC but you will point above the new lead, leave it about 6mm proud and point to a feather edge on that level for a run off.

BertieUK

cyclonebri1 Again I thank you for your input. I will follow your advice and get the job done in the next few weeks.

kind regards

BobUK

mikey72

What about under the old dpc?

BertieUK

Mikey it would appear that it will be enclosed below the suggested lead DPC, according to the way I read it.

Regards

BobUK

cyclonebri1

If you point over the old dpc there is a possibility of bridging the Damp course, by inserting above and bending down the lead none of the new pointing is in contact with the old dpc, you are simply pointing the gap between the lead and the upper brickwork.
This also ensures water cannot run into the joint as the lead effectively slopes down and out of the wall,:T:T the old dpc id "enclosed" as you said,

Good luck,

mikey72

So effectively you propose not to replace the mortar you have dug out below the dpc, and just bend the lead down to cover the gap?

BertieUK

Mikey... Sorry I should have made that clear, I intend to insert the new DPC firmly in place, then bend the DPC into a sloping position to let the rainwater run off, protruding it 6mm over the edge, then carefully fill the remaining cavities,above the DPC with a mortar mix, finishing it off with pointing to a feather edge.

Cyclonebri1 suggested : IE the lead will sit over the existing DPC but you will point above the new lead, leave it about 6mm proud and point to a feather edge on that level for a run off.

Mikey... Maybe I should run a small amount of mortar under the old DPC before I secure the lead DPC prior to pointing above it.

Hope that you kind gents are in agreement and I hope that I do it justice, if not you can use your right of 'Freedom of Speech'

All the best

BobUK

PS I maybe not the sharpest knife in the drawer but I will give it my best shot.

mikey72

I use lead for flashing, but never use lead for a dpc, but's that's my choice. If you are, you need to fill the gap below the existing dpc, to give substance to bend the lead over on, as you need to have something to bend it against. Otherwise it'll just fall out with your new mortar, and crack the old dpc off. I prefer to put the new dpc below the old one, again my choice but it also keeps any damp below the old dpc, rather than above, and gives you something to fill against. Put it in, fill the mortar below it. When it's dry, mortar above it. Let it all go off, then you can hit it with a hammer, use a piece of wood to get a neat bend. Or you could try a wallpaper seam roller if the lead will bend easily. Mortar will stain the lead, so wipe it off as you go. But tbh, if you are moving, lead isn't cheap, and I'd still use plastic and wouldn't worry about bending it. And you've never tried cutting 8ft of lead into 1" strips. If you do want to use the lead on top of the old dpc, fill the bottom with mortar, don't worry if you come out over the edge of the old dpc, but get it good and square, the new lead will cover it, you need to have good base to bend the lead on.

BertieUK

Mikey...Again many thanks for your input. We all have differences of opinion, this is quite natural, and the one that is chosen, is the one that you feel most comfortable with at the end of the day. I believe that this final choice is one that I feel which fits the bill best. The two conclusions are totally correct, so I think that I will sleep on it and decide when my brain is more refreshed. I can only thank all involved and say that I am grateful for all suggestions that have been made and the time and help that you have given me.

Kind regards

BobUK

cyclonebri1

mikey72 wrote: »

So effectively you propose not to replace the mortar you have dug out below the dpc, and just bend the lead down to cover the gap?

The lead will bend the old dpc down, there will be no void left.

I've actualy used lead several times to "insert" dpc in terraced houses that had none, it will last, longer than tar felt. Mortar will grip effectively to lead, but the lead plugs I mentioned are critical and it's no different to the standard method of fitting lead flashing over windows etc.