newhome

Render issue. Need advice on what to do please

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At the bottom of my house the render that was put on has for want of a word ‘blown’.  Not all of it but large parts of it. I went out and scraped some of it off to take these photos and it’s damp with what looks like earth or sand or something behind. None of the render on the walls is affected, just the bit where the earth was backfilled and then gravel laid. Not quite sure what to do with it. Clearly it all needs to come off and be redone but I want it done properly and am worried about something more sinister going on. Any advice welcome please. 

 

 

 

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@newhome  The bell cast is usually fitted level with the DPC.  All the white render is above DPC so will be nice and dry.

 

The grey render underneath is below the DPC.  So it WILL get damp and often the render will blow.

 

This seems to be a very Scottish thing.  When I was down south, nobody rendered below dpc, they did that bit in nicely pointed bricks and left it bare.  I had a problem with my 1930's house where it had been rendered bridging the dpc and that was causing damp in the house, solved by hacking off the render below dpc and pointing the brickwork.

 

So when I came to Scotland I was frankly horified that they render below the DPC.  I have even seen some houses (one I wired 2 years ago) where the white wet dash just goes straight down to the ground bridging the DPC.

 

In your case I would say the scratch coat has far too much sand, not enough cement.

 

On my new build I have left the block work bare below DPC and to make it look nicer, painted it with masonry paint.

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Thank you. What's the bell cast? The bit at the bottom of the white render? Should I scrape it all off then? And it's ok for it to be damp like that? I painted it black at the bottom with masonry paint so I suppose I could paint it again with that once it's off, assuming I can paint on damp brick. Do you think I need to dig down to get all of it off or just leave it? I think some of the ground was backfilled quite a way down so not sure it's feasible to get all of it off anyway. 

 

Any chance of a photo of yours so that I can see what it's supposed to look like please.  

 

Sorry, lots of questions :S

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Random link but it's basically a trim/bead that gets attached to the wall before rendering. Sometimes plastic, sometimes steel though you want st/st ideally not galvanised. The render goes on then tapers out at the bead like the base of a bell. The profile is slightly tapered down on the underside. This is just above the dpc. As well as shedding water and preventing it getting under the render it strengthens the edge of the render as a whole helping protect against knocks and scrapes.

 

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I feel your pain! The very original bit of my place is rendered straight across the dpc. Later bits, like the garage have had a bit of 2"x1" nailed on at dpc level to render down to and form a taper. Its a classic short cut / bodge. Looks pretty if you can get the batten off without pulling the formed bell off but weak as Hell in the long run! Might just work if a super strong mix laden with adhesive.

 

The damp wall in the bathroom was due to a bridged dpc. For that matter the ffl inside was slightly above the inner leaf dpc! A "bit" of digging a couple of years back sorted that! :)

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Thanks. Wonder why they do it like that up here? 🤔

 

Found this old photo after the walls had been rendered. It’s not very good but shows the transition between the main wall and below a bit better. 

 

 

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@ProDave any chance of a photo of your ‘bottom’ please? 😉

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I hear you’ve just got a load of private messages!

 

 

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