Reflashing victorian terrace and repairing brick-on-edge coping

[DavV101]

We’re having leaks though the cement fillet flashing between the roof and parapet walls on our victorian end-of-terrace. As such, we want to replace the flashing with lead whilst at the same time patching up the top of the parapet walls themselves (brick-on-edge coping) as many of the bricks are pretty knackered along with gaps in the pointing and plants growing!

We’re getting 3 quotes but they’re all suggesting different solutions and I’m struggling to work out what is worth spending the money on.

For the flashing:

• step flashing chased and wedged into the brickwork joints.
• lead fixed with stainless steel render bead and render to corbelling.

For the parapet wall repair:

• remove plant growth, minor re-pointing and treat with Thompson’s Water Seal.
• render over the entire top of the wall to the corbelling.
• twice weathered coping stones along top.

The last guys argument for the render bead was that the step flashing wasn’t really worth it on the old walls and the repointed joints are likely to drop out.

My main questions are:

1. Does step flashing work on old bricks and parapet walls?
2. Is there any point in putting Water Seal on the top of the old brick-on-edge coping?
3. Will the render simply crack on top of the parapet wall if used as an alternative to proper coping? They said they would guarantee the whole lot for 10 years.
4. Does anyone ever use metal coping on these kind of parapet walls? Seems to me like it would be ideal, as quick and light to install.

Any replies gratefully received!

Thanks,
David

 

[freddiemercurystwin]

Got a photo or two of what's there now? And not just a close up but so that we can see things in context.

 

[DavV101]

A few pictures of the front:

 

[ree]

The odds are that water is entering below the flashing - the flashing is incorrectly installed, its too shy/narrow, and has not been dressed across the marley major conc tiles.

The fillet and cover tile and lead will have to be lifted along the parapets and chimney stack abutments.

New, wider lengths of lead will have to be chased into the brickwork and dressed over the tiles see calderlead.co.uk abutment flashings (or similar) - only you cannot use stepped flashing, the chase in the parapet has to be on the rake, a long slanted slot.

The fillet on the corbelling must be replaced and possibly selected perished bricks on the top edge of the parapet.
Rendering over the top and down to the corbelling might work - it will work in with your neighbour's parapet render.
Coping stones will also work but they must be a party wall decision.

FWIW: you have four air ventilation terminals on the stack - presume you have no active fires or heaters of any kind?
Are the four flues vented below and have the flues been swept and smoke tested?
Pic 1. shows water staining at and around the fascia and soffit - are water stains present in the bedroom near the bay?

 

[DavV101]

Thanks for your reply Ree and point towards the abutment flashing detail.
So the new lead has to be chased in 25mm, and come out 150mm+ dressed into a low point on the profiled tile.
What is the reason that stepped flashing will not work in this case, as some are still trying to sell me this?

Yes, all the flues have been capped as there are no active fireplaces or heaters and all have vents, but no idea about whether they've been swept or smoke tested. Is this still relevant?
On the staining, we had a loose tile just above the bay that caused a leak a couple of years ago, but since it was put back all has been fine.

 

[ree]

Ref the step flashing - the brickwork below the corbelling has been laid on the slant. Anyway, thats how it appears on my screen. The chase is cut with an angle grinder.

The staining looks more recent esp. the yellow stained render - moisture could be finding its way down from the faulty flashing.

The flues were a FWIW observation. If at any time you see staining on the chimney breasts then it could be sooty flue chemicals leaching thro because the flue was not swept - esp pertinent on an exposed gable. But your thro venting will help prevent this.

 

[DavV101]

Thanks for that.
Once the work is done, I'm going to tidy up the front of the house so hopefully will see if anything is still coming through.

 

[catlad]

I have yet to see any that don't leak knock it off and tile it over.