Jump to content

sealant for between concrete roof and brick wall


paul1966
 Share

Recommended Posts

Re the dip,,,, can sort of see what you're describing. Still doesn't look right 🤔

The two separate lead flashings are basically doing nothing,,,, but 'sucking' water back to the roof/wall junction using capillary action. You can use as much sealant as you like,,,, that sealant is the only thing stopping the ingress. On a 'flat' roof that system will not work. I've seen pitched roofs with the same issue.

As it stands, if you take the lead away and seal the 'junction', that will do a temporary fix.

TBH, for a proper fix, I would wrap it with a roofing sheet layer,,,, 3 layered mineral felt, rubber, fiberglass. With firring pieces and 18mm ply, and 18mm ply verges to keep things not protruding past the existing roof area.

Edited by JKD
Link to comment
Share on other sites

OK,,,, now you've told us your future plans 👍

Wait until it's dry weather,,,, carefully lift both lead flashings,,,, you can do it in sections and support the lead with timber,,,, dry area beneath with a hot air gun/paint stripper, being careful near the lead,,,, layer lots of lead/gutter sealant to the area,,,, re-dress the lead.

That should do the job until your improvements,,,, hope that helps 😉

If you look carefully you can see the small i-beams in the concrete slab.

Edited by JKD
Link to comment
Share on other sites

5 hours ago, paul1966 said:

its just a bare concrete slab, its darker due to the rain, the dip in the picture is just a shallow pool of rain water not a sunken area. i have been up on the slab and its in good order, its just the lead flashing that needs looking at, you are correct it has been repaired before. I think i need to lift the flashing up and see whats underneath if anything.

you'll never get a seal on it if its just flashing sat on the slab ,no amount lead mate will fix a bodge.

lead moves when it warms up hence the max length rule when installing flashing.

you could do the whole thing in felt with a 45degree fillet at the wall slab junction with continued up stand of felt.

if the concrete is flat enough you could prime with G4 add your edge trims bonded or fixed and grp the whole thing.

or you could board onto the concrete slab with vapour barrier and or kingspan then trim and grp the whole lot with 45 fillet upstand.

 

Link to comment
Share on other sites

If there is a parapet then my only advice would be to price for insulation above as a warm deck with falls and covering in a single ply membrane turned up the parapet and any wall abutments. Get a few quotes from specialist roofing contractors and then make a decision. 

You can do it badly with lead and sealant to try to slow the water ingress and decay, but it will not work long term. The original construction is typical an old garage roof etc, a space not intended for inhabitation. If/when you sell it is likely/possible the buyer’s surveyor will notice. 

Link to comment
Share on other sites

Funnily enough I was going to send a link to Firestone. We historically specified Sarnafil for single ply but over the last few years have had some projects VE’d or D&B’d to Firestone. It is actually a great product, and the approved installers have been well trained. I had to condemn one roof, it was done badly and bubbled. The client had paid a pal cash (always alarm bells) to do it but not sure he was actually an approved installer, the replacement by another approved installer was perfect however. 

Edited by WalkedUp
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...