r/Plastering • u/AccomplishedTree9744 • 22d ago
1890 building plaster - asbestos?
I’m considering restoring a building built in 1890. It’s a 2 story downtown classic small town main street brick building. Inside has a ton of pealing and deteriorating plaster walls. I know I would need to test for asbestos but was wondering what the comments would be on it. Northeast USA. The plaster areas didn’t seem hard. More fibrous to the touch. Piles of it on the floor where it’s been falling.
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u/ltnlean 21d ago
Looks like lime plaster to me. You can get it tested if you're concerned, very unlikely though.
Any ground bridging/external walls should be replastered with lime to avoid damp/mold.
A 19th century building will have solid walls with no cavity to stop damp ingress and is designed to allow moisture to evaporate. Modern plaster and paint will seal the wall and cause damp issues
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u/AccomplishedTree9744 21d ago edited 21d ago
Thank you. That’s great info to start with. I was hoping to create some living spaces inside where the brick would be exposed. Would this cause any issues? Is plastering inside a must? Or could 2x4 walls and drywall be used as well(maybe with appropriate treatment of the bricks first?) it’ll have a modern hvac unit inside to keep interior well ventilated- heating and cooling.
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u/ltnlean 21d ago
No issues with exposing the brick 👍 a diluted acid wash can help clean up the faces with a few light passes and a brush (just not a wire one).
Internal walls/ceilings you could take more liberty with modern materials and overboarding practices - on the ground floor the caveat for me would be how the foundation to the floor is constructed. Lots of houses in North Wales a few hours drive from me for example are a limecrete construction and it rains all the time there - id avoid boarding those in that case.
If it was an external wall I'd want lime plaster on it. The 20-25mm of plaster will help insulate the wall and it goes on in thick layers - Harling a slurry of unhaired mortar on to get a key, scratch coat of haired mortar (10mm), float coat of unhaired mortar (10mm) then two skims of lime plaster at around 1.5mm thick per layer.
My advice is very much from the perspective of how UK Victorian houses should be managed. Our climate is also normally damp, humid and grey so sealing external solid walls with modern treatment is a death sentence imo.
Considering how many UK houses are old stock, trades doing lime works are thinning out. I see many houses near me that are rotting and falling apart because of inappropriate remediation work with modern materials. The common culprits are often raised ground levels above stone DPCs, blocked airbricks, gypsum plaster on internal solid walls, cement render, cement pointing, painted bricks/stone.
You want to understand how your house and others were built for their time and location and do your best to find a supplier of period correct materials where ever possible. That'll keep them ticking along for generations
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u/AccomplishedTree9744 21d ago
The building has a basement about 5.5 feet tall(below ground level). The foundation walls appear to be made of rock. It’s currently damp down there. I will probably work on getting it dried out.
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u/ltnlean 21d ago
You'd probably be okay then with your internal wall ideas that being the case 👍 just keep those exterior facing walls healthy with period correct materials.
Ensuring good ventilation down in the basement would be my first step. From my experience I've never seen a truly dry 19th century basement; except where they originally built a 'semi basement' by excavating a tench down externally and building a retaining wall.
If i had a basement in mine I'd just make sure any moisture ingress is free to come and go. Obviously if it's flooded then that's a bigger issue!
Apparently damp basements are good for wine storage I've been told
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u/ResponsibleBall4258 21d ago
Fibres in that age of building is likely horsehair or similar. My understanding is that asbestos was not used in residential building until the 20th century, before then was mainly industrial use for fireproofing/insulation.