Lime / Hair Plaster

[Pete.]

id be watching yourself stripping the plaster off lime and horsehair might contain anthrax get that in a cut and you will know about it wasn't just horsehair they used

I was gonna mention anthrax too. I doubt it's much of a risk but the risk is still there.

 

[Onoff]

At the moment we're stripping the walls of painted wallpaper to see what we're up against.

I've noted a leak in the loft too so some roof investigation needed.

Will report back in due course.

 

[Onoff]

What would be a worthwhile mask set up for taking this plaster off? I'm not rushing into it. Thinking maybe air fed / battery powered would be wise. Cheers.

 

[brightspark]

just a decent respirator with cartridge filter will be fine i never wore them for years at work i do now still healthy as well breathing wise

 

[julianf]

What would be a worthwhile mask set up for taking this plaster off? I'm not rushing into it. Thinking maybe air fed / battery powered would be wise. Cheers.

When we have done it at our own home, ive used my air fed mask with remote air, but then i had pnumonia a few years back, and am maybe more cautious. For examples that are not my own home - ive always managed to persuade of the savings to doing that bit themselves...

If you can get a standard mechanical mask to seal on your face you should be fine with one of them. I can never get a seal though.

The dust will get through your whole house, even with doors closed. If you can work out some sort of negative pressure setup in the room that youre working in, that would work well (ive never managed it)

 

[Onoff]

The dust will get through your whole house, even with doors closed. If you can work out some sort of negative pressure setup in the room that youre working in, that would work well (ive never managed it)

Not living in it so I can make as much mess as I want tbh. Still a mission!

 

[Cobbler]

Many years ago, my father was doing up a cottage for our Gran. All the inside was being gutted, old plaster that had been there since the 1690’s. The dust was terrible so Dad found his old wartime gas mask, who know why he kept it, & was working in there in shorts no shirt & gas mask. All the old dears used to be nosy & peer in through the window to see how work was progressing, this time were confronted by clouds of dust, & a figure looming out of it with a gas mask on. The old dears screamed & shot off up the road.

 

[julianf]

I've just remembered...

I was working on ours once. Dust was so bad that I couldn't see my own feet.

There was a knock on the door. Neighbour came over to make sure the house wasn't burning down, as the dust was blowing out of one of the windows.

It's not insignificant.


(this was before I had air fed kit, and do wonder if that may have been a factor in my propensity to pneumonia etc years later)

 

[Seadog]

I was working on ours once. Dust was so bad that I couldn't see my own feet.

Are you sure that it was the dust stopping you?

 

[Dragnet]

Hydrated ("bag") lime and slaked ("fat") lime putty are NOT the same thing. There is not 'woo' associated with lime that I'm aware of, but a lot of work by building physicists, architects and builders trying to undo some of the damage done by fast'n'cheap modern materials that are now proven to have ill effects on health as well as the environment. Of course, we're way behind Europe where the defacto 'Bauphysik' software includes vapour transfer as a matter of course. Bag lime is quicklime slaked with a shortage of water, while fat lime is slaked in an excess of water and left to mature for several months. Chemically similar but functionally different. Bag lime is a plasticiser for cement mortar, and starts to carbonate as soon as it's made. If used immediately in a fresh batch, it will likely work for a limewash but I would not use it for any serious plasterwork.

Working with fat lime is brilliant. It's forgiving, less unpleasant than cement and there's no concern about taking time as yesterday's can be whipped up again. The workability is very pleasant.

I'm afraid that your efforts with an injected DPC will likely have been entirely wasted. Rising damp is mostly a myth caused by overzealous use of impermeable coatings which create a problem that wasn't there before. We still have Elizabethan timber buildings where they used a dwarf wall to raise the sill plate off the ground, and lime to bed it in. The raising from the ground protects the timber from water and rain splashes, while the alkaline lime has an antimicrobial effect.

I'm writing this in a C18/19th stone pig sty conversion, where the solid rubble walls sit on the ground and it's hard to tell where they end and the ground begins. It was badly converted: the floor is cast concrete directly on the ground and the walls are covered in cement and acrylic paint. The floor causes a hydrostatic pressure which forces water up into the stones and blows off the paint. The problem here is not lack of a DPC. Where we have removed the floor and the cement render and limed the wall, it's dry. Capillary action will only raise water above a saturated area by a small amount, so unless you're living in a swamp, exterior drainage to prevent flooding and permeable coatings will deal with the moisture. The Society for the Protection of Ancient Buildings has some information here.

I'm afraid anything you do that doesn't improve ventilation and allow the building fabric to dry out is going to be a sticking plaster at best. If you're rigorous with application of breathable materials you'll find your internal air quality will be improved, too. Moisture buffering (absorbed by materials when humid, released when dry) in an old house is a lot better on the sinuses than an arid, sealed, off-gassing new build. Rather like an old car, there is no getting away from the fact that it's a lot of work to undo a PO's (perhaps well-intentioned) efforts, simply because the temptation in the middle of the C20th to use all the flashy modern materials had rather more far-reaching consequences than anyone understood.

I would advise against replacing suspended floors with slabs, unless you use limecrete, LECA/foamed glass insulation and breathable finishes. Dry-laid Lithotherm tiles on breathable insulation is possibly an easier option. I'm about to lay solid ash floorboards on mine. You really want to avoid anything impermeable as it's going to cause problems with your solid walls.

Wood wool board is great. I've used Savolit and Celenit on several projects. An excellent key for three coat hair/lime, and also often used as a finish in its own right. A finer 'wool' finish is available from Heraklith if you want to leave it exposed. Pretty much fire, water and frostproof and provides a bit of buffering. I can't imagine using gypsum board again.

Dust is horrid. There's no getting around it even with damping it down. If you have an air-fed respirator ensure the compressor is situated some way away!

Perhaps it would help to consult a local conservation architect. They could advise on your specific situation and the way all these materials interact can be quite complex. I'd consider radiant heating panels rather than central heating with radiators (convectors) - rather more efficient and better for the building fabric, too.

 

[Onoff]

Thinking of getting a couple of cheap full face masks like this for stripping the walls. Are they any good & will it be easy enough to get replacement filter pads?

https://www.amazon.co.uk/Respirator-Organic-Vapor-Paint-Spray/dp/B0BS3P7B77/ref=mp_s_a_1_5?

The walls then, this is the dining room:

IMG_20231107_164127803

Explore Mustafa Crackatthat's 9828 photos on Flickr!

flic.kr

https://flic.kr/p/2pfZdhi

A little video with me digging at the bit above, it reveals red, stock bricks:

https://flic.kr/p/2pfZUPm

Layers of thick paint on the door linings, wooden lintels above:

https://flic.kr/p/2pfZd5j

https://flic.kr/p/2pfYDrY

https://flic.kr/p/2pfZNoL

The chimney stack wall and reveal to the right:

IMG_20231107_164226728

Explore Mustafa Crackatthat's 9828 photos on Flickr!

flic.kr

IMG_20231107_164238813

Explore Mustafa Crackatthat's 9828 photos on Flickr!

flic.kr

 

[Gareth J]

Hydrated ("bag") lime and slaked ("fat") lime putty are NOT the same thing. There is not 'woo' associated with lime that I'm aware of, but a lot of work by building physicists, architects and builders trying to undo some of the damage done by fast'n'cheap modern materials that are now proven to have ill effects on health as well as the environment. Of course, we're way behind Europe where the defacto 'Bauphysik' software includes vapour transfer as a matter of course. Bag lime is quicklime slaked with a shortage of water, while fat lime is slaked in an excess of water and left to mature for several months. Chemically similar but functionally different.

View attachment 423414

Explain to me, chemically, the difference between hydrated lime "bag lime" if you will, that has as you mentioned been soaked in an excess of water for the timeframes you mention and fat lime bought specifically for the purpose. To the best of my ability, a few years ago, I searched high and low for the explanation. Reading relevant scientific papers as well as press articles. This one is particularly interesting;

https://www.sciencedirect.com/science/article/abs/pii/S0950061819319026

Notes some of the differences between mixing powdered lime and using soaked lime. Neither option is bad, both have advantages and disadvantages. People who sell you their fat lime will say that it's better but not how or why other than claims on purity or fineness. Along with, often a healthy dose of green woo.

I claim that, for general building, cheap(er) bag lime, soaked if you need the properties it gives as noted in the reference above, mixed straight if not, is more than adequate. If you can explain why I shouldn't do this, please elaborate with references explaining specifically why. Like I said, I spent ages trying to find what made special limes special, so I'd genuinely like to know!

What I won't do with cheap cubicle lime, is plaster top coats. I've tried that. It works as you'd expect but there is too much sand with it.

What does produce a very significantly different outcome though is building with "hot" lime. Seen the results in a lot of the walls that I've taken down here.

 

[JimmyS]

Thinking of getting a couple of cheap full face masks like this for stripping the walls. Are they any good & will it be easy enough to get replacement filter pads?

https://www.amazon.co.uk/Respirator-Organic-Vapor-Paint-Spray/dp/B0BS3P7B77/ref=mp_s_a_1_5?

The walls then, this is the dining room:

IMG_20231107_164127803

Explore Mustafa Crackatthat's 9828 photos on Flickr!

flic.kr

https://flic.kr/p/2pfZdhi

A little video with me digging at the bit above, it reveals red, stock bricks:

https://flic.kr/p/2pfZUPm

Layers of thick paint on the door linings, wooden lintels above:

https://flic.kr/p/2pfZd5j

https://flic.kr/p/2pfYDrY

https://flic.kr/p/2pfZNoL

The chimney stack wall and reveal to the right:

IMG_20231107_164226728

Explore Mustafa Crackatthat's 9828 photos on Flickr!

flic.kr

IMG_20231107_164238813

Explore Mustafa Crackatthat's 9828 photos on Flickr!

flic.kr

I just used the the disposable P2 masks when stripping the old lime plaster in our place so think the full face job would be many times better. I think if you are concerned about anthrax risk then cuts/ grazes are a potential entry point for spores as well but might be wrong.

The ceilings were the mankiest job after the mess taking down the first one, I isolated the electrics, stripped out the loft insulation and went up with watering cans and drenched the whole lot till I could see the water coming through. Then took the ceilings down. Still bloody messy job but not nearly as dusty.

Good luck with it

 

[OJCar]

Thinking of getting a couple of cheap full face masks like this for stripping the walls. Are they any good & will it be easy enough to get replacement filter pads?

https://www.amazon.co.uk/Respirator-Organic-Vapor-Paint-Spray/dp/B0BS3P7B77/ref=mp_s_a_1_5?

Would you be consider wearing it whilst welkding ?

 

[Onoff]

Would you be consider wearing it whilst welkding ?

Damn right! Looks like it'll be spot on too come the zombie apocalypse:

 

[Roger440]

Hydrated ("bag") lime and slaked ("fat") lime putty are NOT the same thing. There is not 'woo' associated with lime that I'm aware of, but a lot of work by building physicists, architects and builders trying to undo some of the damage done by fast'n'cheap modern materials that are now proven to have ill effects on health as well as the environment. Of course, we're way behind Europe where the defacto 'Bauphysik' software includes vapour transfer as a matter of course. Bag lime is quicklime slaked with a shortage of water, while fat lime is slaked in an excess of water and left to mature for several months. Chemically similar but functionally different. Bag lime is a plasticiser for cement mortar, and starts to carbonate as soon as it's made. If used immediately in a fresh batch, it will likely work for a limewash but I would not use it for any serious plasterwork.

Working with fat lime is brilliant. It's forgiving, less unpleasant than cement and there's no concern about taking time as yesterday's can be whipped up again. The workability is very pleasant.

I'm afraid that your efforts with an injected DPC will likely have been entirely wasted. Rising damp is mostly a myth caused by overzealous use of impermeable coatings which create a problem that wasn't there before. We still have Elizabethan timber buildings where they used a dwarf wall to raise the sill plate off the ground, and lime to bed it in. The raising from the ground protects the timber from water and rain splashes, while the alkaline lime has an antimicrobial effect.

I'm writing this in a C18/19th stone pig sty conversion, where the solid rubble walls sit on the ground and it's hard to tell where they end and the ground begins. It was badly converted: the floor is cast concrete directly on the ground and the walls are covered in cement and acrylic paint. The floor causes a hydrostatic pressure which forces water up into the stones and blows off the paint. The problem here is not lack of a DPC. Where we have removed the floor and the cement render and limed the wall, it's dry. Capillary action will only raise water above a saturated area by a small amount, so unless you're living in a swamp, exterior drainage to prevent flooding and permeable coatings will deal with the moisture. The Society for the Protection of Ancient Buildings has some information here.

I'm afraid anything you do that doesn't improve ventilation and allow the building fabric to dry out is going to be a sticking plaster at best. If you're rigorous with application of breathable materials you'll find your internal air quality will be improved, too. Moisture buffering (absorbed by materials when humid, released when dry) in an old house is a lot better on the sinuses than an arid, sealed, off-gassing new build. Rather like an old car, there is no getting away from the fact that it's a lot of work to undo a PO's (perhaps well-intentioned) efforts, simply because the temptation in the middle of the C20th to use all the flashy modern materials had rather more far-reaching consequences than anyone understood.

I would advise against replacing suspended floors with slabs, unless you use limecrete, LECA/foamed glass insulation and breathable finishes. Dry-laid Lithotherm tiles on breathable insulation is possibly an easier option. I'm about to lay solid ash floorboards on mine. You really want to avoid anything impermeable as it's going to cause problems with your solid walls.

Wood wool board is great. I've used Savolit and Celenit on several projects. An excellent key for three coat hair/lime, and also often used as a finish in its own right. A finer 'wool' finish is available from Heraklith if you want to leave it exposed. Pretty much fire, water and frostproof and provides a bit of buffering. I can't imagine using gypsum board again.

Dust is horrid. There's no getting around it even with damping it down. If you have an air-fed respirator ensure the compressor is situated some way away!

Perhaps it would help to consult a local conservation architect. They could advise on your specific situation and the way all these materials interact can be quite complex. I'd consider radiant heating panels rather than central heating with radiators (convectors) - rather more efficient and better for the building fabric, too.

View attachment 423414

Pretty much all of this ^^^^.

My house, well the last one, was an 1850's cottage withe new extension, Extension was fine, original part had the full list of modern @fixes@ creating damp.

In the end, stripped back to brick, took up the concrete floor that was laid on mu, lowered the outside ground levels, vented cap on the chimney etc, etc. Used to be sitting at circa 90% humidity most of the time. Outside, below the render line, all the crap repointing in cement was removed and lime re-instated.

The walls were so wet that the socket back boxes had rotted away. Having removed everything, a couple of months saw it completely dry, the floor being dry dirt. The was late winter. Before if you drilled a hole in the wall near the floor, it came out as a slurry. Once dried out, was just dust, even at floor level.

Whilst i had read up on it, to see it happen, as quicklyt as it did, was staggering.

Re-instament was, foamed glass base, limectrete floor, lime plaster. And suitable breathable paint.

3 years on, still completely damp free. Sits at circa 50-60% humidity.

As others have said, do not fight damp. It always wins. Work with the moisture, allow it to evaporate just as it did before moronic builders turned up with cement and gypsum!

 

[Onoff]

The walls were so wet that the socket back boxes had rotted away.

Interesting. The kitchen is rendered with modern materials. This socket back box is rotten:

https://flic.kr/p/2perSUh

The other side of that wall, again rendered, plastered and painted with modern stuff:

https://flic.kr/p/29f6HNs

 

[Roger440]

Interesting. The kitchen is rendered with modern materials. This socket back box is rotten:

https://flic.kr/p/2perSUh

The other side of that wall, again rendered, plastered and painted with modern stuff:

https://flic.kr/p/29f6HNs

That looks as wet as a wet thing!!!

Sadly, all too common.

The only proper answer will be much like ive done. Major work sadly.

Ive gone and bought another house so i can do it all again too!

Started with the fireplace for now as a trial. All been pointed with cement. All cold and damp to the touch. Knocked out the cement pointing. Behind was the original lime. Soaking wet. Soft enough in places to push your finger into. 9 Months later, completely dry. Much slower as Its 2 foot thick stone wall. But, again, just proves the point.

 

[Gritineye]

A lot of my work involved pulling down old lime/horsehair mortar ceilings loaded with old thatch, lath and plaster and general mayhem, in occupied period properties.

I had acquired a big fan out of a mushroom growing shed, which got fixed in an open window by any means that worked, a door or another window was propped ajar for air flow.

As long as I worked towards the fan I would be in clean air, even the floor would stay clean. Last time I used it was on an architect supervised job and I had to stop using it as it was deemed to be a H&S hazard!!!

I can honestly say that not a drop of dust or debris ever got out of the area I was working in unless it went through the fan to the outside, I've still got the fan which has a few chunks out of it as bigger bits passed through.

Not sure if towney neighbours would think much of it but I was a country builder.

 

[Pete.]

Thinking of getting a couple of cheap full face masks like this for stripping the walls. Are they any good & will it be easy enough to get replacement filter pads?

https://www.amazon.co.uk/Respirator-Organic-Vapor-Paint-Spray/dp/B0BS3P7B77/ref=mp_s_a_1_5?

The walls then, this is the dining room:

IMG_20231107_164127803

Explore Mustafa Crackatthat's 9828 photos on Flickr!

flic.kr

https://flic.kr/p/2pfZdhi

A little video with me digging at the bit above, it reveals red, stock bricks:

https://flic.kr/p/2pfZUPm

Layers of thick paint on the door linings, wooden lintels above:

https://flic.kr/p/2pfZd5j

https://flic.kr/p/2pfYDrY

https://flic.kr/p/2pfZNoL

The chimney stack wall and reveal to the right:

IMG_20231107_164226728

Explore Mustafa Crackatthat's 9828 photos on Flickr!

flic.kr

IMG_20231107_164238813

Explore Mustafa Crackatthat's 9828 photos on Flickr!

flic.kr

Yuo need a jack for all that.