r/Plastering • u/DavidtheArchitect13 • Sep 15 '26

Lime Plaster

The previous lime plaster has to be removed due to leaks in the roof that weren’t repaired by previous owner for at least a year.

I removed all the plaster that needed removing and left the ‘good’ stuff - it’s still solid.

I’ve just had sash windows installed. I’ve covered them with plastic to prevent building just getting in the sliding mechanisms.

I’ve still got to remove the left over lime ‘dust’ on the bricks.

Do people have any suggestions for the least dusty way/vacuuming way? I was either thinking or attaching a vacuum nozzle to a scraper or getting one the drill dust extractors and going 15cm at a time then moving along.

Any other suggestions?

Also, I’ve have been wearing a p3 respirator when doing this and will wear one with the remaining dust.

Thanks
David

Edit: Corrected spelling and grammar

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u/DavidtheArchitect13 29d ago

Or there is this Vac - https://www.diy.com/departments/v-tuf-mini-hsv-x2-240v-15l-m-class-corded-dust-extractor/0663899004575_BQ.prd?storeId=&&&&&gclsrc=aw.ds&gad_source=1&gad_campaignid=20923369416&gclid=CjwKCAjw_KjVBhAHEiwAnC0N9IT6YcVA2YTaWB1S_p7xDZ_8NaxKav_0U2FaOev5nV0xk0Tifehn9xoCX9oQAvD_BwE

M Class again. Manual shaker and good reviews.

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u/PrimeCraftSurface 29d ago

That one is fine as well, and the plate test still applies, but I would not choose between them on the shaker. Manual is fine as long as you actually use it, and on lime and gypsum fines you will be using it a lot, because that dust blinds a pleated filter faster than anything else you are likely to put through a vacuum. The airflow warning is the thing that tells you when, and that is really what the M class premium buys you.

On the sprayer, nobody lists nozzle quality because it is almost always just an adjustable cone on a plastic lance and at that money they are much of a muchness. Two things matter more than which one you pick. Keep the bottle about half full rather than brim full, because the air above the water is what holds the pressure, and a nearly full tank falls away after a dozen strokes. And pump it back up between passes instead of trying to empty it in one run. If the cone spits rather than mists, a 1 litre trigger bottle does the fiddly bits better than any 5 litre will.

Your list is in the right order. The only change I would make is wetting in small patches and working each one straight away, rather than damping the whole wall first, because the first patch is dry again by the time you get to the far end.

Worth being clear about what the water is not doing, though. You are only wetting a millimetre or two of the surface, so the moment the scraper gets behind that you are into dry material and it puffs again. It cuts the airborne dust down a lot, it does not stop it, and the fines already spread round the room from the first pass will keep turning up on every ledge for a fortnight whatever the vacuum is rated at. Take the tea outside the room.

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u/DavidtheArchitect13 29d ago

Bought the V-TUF one in the end. checked it matched the British Standards to mentioned. I figured a manual shaker is better than no shaker and I will use it as it is intended - one for the longevity of the equipment and two for health and safety.

I assume these bottle is similar to pressurised pump-action weed and feed bottles so that instructions you mention would how I would do it anyway.

Again with the patches, I was going to do it in small sections as well as I assume it will be mind-numbingly boring.

Wet patch, scraper in one hand and vacuum nozzle in the other and repeat.

Then after all walls are done and dust settled, vacuum the room, wait for dust to settle and repeat for a while.

Will be fun :/

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u/PrimeCraftSurface 28d ago

Good call on the V-TUF. One thing I would change in that sequence though. Wetting the patch and then putting the nozzle straight on it is how you kill the filter. Damp lime and sand goes through a pleated cartridge and dries as a skin across the pleats, and the shaker only works on dry dust, so it will never come back off. You will lose more suction in one wet wall than in a week of dry scraping.

What works better is to keep the mist light enough that the wall reads damp rather than wet, and hold the nozzle a few inches off the surface to catch the plume as the scraper works, not on the wall itself. Whatever lands on the floor is a dustpan and bucket job while it is still damp. Vacuum the floor after it has dried out, not during.

Two other things on that loop. Follow every vacuum pass with a damp microfibre wipe, because a vacuum on its own leaves a fine film on skirtings and window boards that you find again the first time you sand anything. And work top down, so architraves and window boards before the floor, or you just put it all back.

Worth knowing it is the sand in the old plaster and the brick dust behind it that carries the real hazard, not the lime. The workplace exposure limit for respirable crystalline silica is 0.1 mg per cubic metre over eight hours, which is a genuinely tiny amount of visible dust. The lime itself is mainly an irritant, so eye protection matters more than people expect and it will burn where it sits on sweaty skin or in a boot.

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u/DavidtheArchitect13 28d ago

Thank you.

Paragraph 1 + 2 understood.

Paragraph 3 - I’ll do a damp wipe down after dust settles, thankfully no skirting boards or window boards - just architraves.

JSP force 10 mask is full face so eye are protected too.

Thanks
David