Curious tar layer at base of exterior wall
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JNAScarb
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Curious tar layer at base of exterior wall

by JNAScarb » Tue Oct 27, 2020 3:29 pm

Hi

I've a 150 year old house in a fishing town and the paint is peeling off the exterior. At ground level, if I peel it off there's maybe just under 1mm of paint and I get to an oily tar layer. It's on the wall, and it's also on the paint I've removed. It's dry, I don't mean it's wet. But I say tar and fishing because maybe it was to hand (for waterproofing boats) and so someone thought it a good idea to seal the wall with it.
Anyway, my question is, so I'm going to be left with patches where I've pulled off paint. Some will be back to brick or stone. Some back to this black tar layer. A positive thought: I did use some toupret exterior filler and that seemed to stick to the black layer so maybe it's not so bad.
My question is, what to level it with .. bearing in mind I'm not a builder :-) .
I had it suggested that I use SBR in two layers as it says on the product, so that says SBR + cement to 1mm, then SBR + cement + sand. Well that would stand proud.
So is the SBR a good idea? If so, can I get away with just one of those layers or do I need both? If just one, which one should I do?
It will be painted with Sandtex after.
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JNAScarb
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Labourer
Posts: 4
Joined: Sun Jan 30, 2011 1:25 pm

Re: Curious tar layer at base of exterior wall

by JNAScarb » Tue Oct 27, 2020 8:56 pm

Sandtex's tech support reckons that bitumen layer has to come off, and to use white spirit to soften it.
OK, but my key question is how to fill the 1mm deep patches where I'm pulling off old paint .. higher up maybe where the tar isn't.

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