Cork lime plaster experience?

[saraheamorrison]

It's really difficult to slake the lime with other materials unless you're used to it. This is why I recommend homeowners make the putty first. You can use it straight away as the chemical reaction has already happened. Maturing putty for months goes back to when it used to be a kibble or stones and would need to sit for months to ensure every part of it has reacted. Modern lime is pure powder so reacts immediately in most cases and a quick mix, ensures it's all done.

Anyway, It sounds like you're learning which is great love it !

 

[aockenden]

It's really difficult to slake the lime with other materials unless you're used to it. This is why I recommend homeowners make the putty first. You can use it straight away as the chemical reaction has already happened. Maturing putty for months goes back to when it used to be a kibble or stones and would need to sit for months to ensure every part of it has reacted. Modern lime is pure powder so reacts immediately in most cases and a quick mix, ensures it's all done.

Anyway, It sounds like you're learning which is great love it !

That has got to be the most coherent explanation I’ve ever heard to explain the strange contradiction that we are told we can slake a quicklime together with the aggregates as part of a hot mixed mortar and use it literally while it’s still warm (aka, absolutely zero aging), but if you slake it by itself WITHOUT the aggregates now suddenly it magically needs to age for 3 months! That never made any sense to me. Thank you for your clarity of thought.

Over the last month of experimenting with quicklime I have also come to suspect that the aging stuff was just to handle the lumps in the original quicklimes.

I took your advice from earlier in the thread and have stopped hotmixing with the hemp and cork together in with the quicklime and I’m just slaking the quicklime by itself in a metal bin, letting it cool overnight, then mixing in my hemp / cork / perlite. Although I do miss the slightly smoky smell permeating the house from applying a mix where some of the hemp burned in the mix…

 

[Mikeyboy7]

Great job looks fab , I’ve been playing around with quick lime for the last year , great product , so if you don’t mind what was your final recipe, thanks again great information

 

[aockenden]

Great job looks fab , I’ve been playing around with quick lime for the last year , great product , so if you don’t mind what was your final recipe, thanks again great information

I assume this is directed at me? The final recipe I settled on which I’ve been using consistently for the last month is:

1.25 buckets of well drained lime putty (made from either quicklime or hydrated lime), not aged more than a day or two typically.

0.25 buckets of NHL 3.5 powder.

1 bucket of granulated cork.

1 bucket of hemp shiv.

Water until sticky but not sloppy or runny. I want it to ball up into slimy snowballs in my hands. I actually just slapped another batch on our second bedroom’s wall this morning. See pic.

Also, nothing is hot mixed. I no longer believe the stories about the value of hot mixed mortars, all a bit too esoteric and “magical” for me to believe in, especially when I’ve found no benefit vs mixing cold with pre-slaked cold putty. Plus I got sick of burning my cork + hemp and melting through plastic buckets.

 

[Mikeyboy7]

I assume this is directed at me? The final recipe I settled on which I’ve been using consistently for the last month is:

1.25 buckets of well drained lime putty (made from either quicklime or hydrated lime), not aged more than a day or two typically.

0.25 buckets of NHL 3.5 powder.

1 bucket of granulated cork.

1 bucket of hemp shiv.

Water until sticky but not sloppy or runny. I want it to ball up into slimy snowballs in my hands. I actually just slapped another batch on our second bedroom’s wall this morning. See pic.

Also, nothing is hot mixed. I no longer believe the stories about the value of hot mixed mortars, all a bit too esoteric and “magical” for me to believe in, especially when I’ve found no benefit vs mixing cold with pre-slaked cold putty. Plus I got sick of burning my cork + hemp and melting through plastic buckets.

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Brilliant, I’ll give it a go , no perlite so , what’s the reason for nhl , was it just for firmness , so a good damping down of the wall , what thickness did you apply (25mm)
Thanks again FairPlay

 

[aockenden]

Brilliant, I’ll give it a go , no perlite so , what’s the reason for nhl , was it just for firmness , so a good damping down of the wall , what thickness did you apply (25mm)
Thanks again FairPlay

We will be swapping out our coarse-ground cork for fine perlite and swapping the coarse-cut hemp shiv for fine-cut hemp shiv on our second insulating coat so we can trowel it flatter in preparation for a final skim coat with only putty and fine sand. The mix I gave above is for the first very rough coat.

The NHL is giving us some early strength within a day or two which mainly protects it from my 18 month old son getting it on his hands when it’s down at his level so we don’t need to keep it blocked from his access for a month. I’m also trying to get rid of some older NHL I’ve got laying around. A couple people have recommended adding it as well for a quicker set and extra durability. Probably not strictly necessary I suspect but can’t hurt.

Yes we damp the stone wall down before applying it with gloved hands. We are applying the two insulating coats at about 20mm each for a total of 40 mm of total insulating lime render, then hopefully just a single sponge-finished standard lime skim coat on-top of that which we’ll then limewash or clay paint.

 

[Mikeyboy7]

We will be swapping out our coarse-ground cork for fine perlite and swapping the coarse-cut hemp shiv for fine-cut hemp shiv on our second insulating coat so we can trowel it flatter in preparation for a final skim coat with only putty and fine sand. The mix I gave above is for the first very rough coat.

The NHL is giving us some early strength within a day or two which mainly protects it from my 18 month old son getting it on his hands when it’s down at his level so we don’t need to keep it blocked from his access for a month. I’m also trying to get rid of some older NHL I’ve got laying around. A couple people have recommended adding it as well for a quicker set and extra durability. Probably not strictly necessary I suspect but can’t hurt.

Yes we damp the stone wall down before applying it with gloved hands. We are applying the two insulating coats at about 20mm each for a total of 40 mm of total insulating lime render, then hopefully just a single sponge-finished standard lime skim coat on-top of that which we’ll then limewash or clay paint

Sounds good

 

[Mikeyboy7]

Sounds good

Sounds good

We will be swapping out our coarse-ground cork for fine perlite and swapping the coarse-cut hemp shiv for fine-cut hemp shiv on our second insulating coat so we can trowel it flatter in preparation for a final skim coat with only putty and fine sand. The mix I gave above is for the first very rough coat.

The NHL is giving us some early strength within a day or two which mainly protects it from my 18 month old son getting it on his hands when it’s down at his level so we don’t need to keep it blocked from his access for a month. I’m also trying to get rid of some older NHL I’ve got laying around. A couple people have recommended adding it as well for a quicker set and extra durability. Probably not strictly necessary I suspect but can’t hurt.

Yes we damp the stone wall down before applying it with gloved hands. We are applying the two insulating coats at about 20mm each for a total of 40 mm of total insulating lime render, then hopefully just a single sponge-finished standard lime skim coat on-top of that which we’ll then limewash or clay paint.

Hi ,
Spoke with a good heritage guy earlier regarding making your own insulation plaster , for what it’s worth, this is what he said :
‘I'd go with hemp and Cork before perlite then. Even one would suffice, hemp can bring mold if not well applied and ventilated, Cork is safer. Big size granules, this is your insulatory coat then fine and skim !

Tnx

 

[aockenden]

Hi ,
Spoke with a good heritage guy earlier regarding making your own insulation plaster , for what it’s worth, this is what he said :
‘I'd go with hemp and Cork before perlite then. Even one would suffice, hemp can bring mold if not well applied and ventilated, Cork is safer. Big size granules, this is your insulatory coat then fine and skim !

Tnx

Yeah do whatever makes sense to you. We used the hemp to keep costs down as granulated cork is relatively pricey in comparison. As for the hemp molding, I’ve heard of that happening if it’s applied too thickly and takes too long to dry (if the wall is perpetually wet due to sone exterior problem like ground level for instance).

 

[aockenden]

Yeah do whatever makes sense to you. We used the hemp to keep costs down as granulated cork is relatively pricey in comparison. As for the hemp molding, I’ve heard of that happening if it’s applied too thickly and takes too long to dry (if the wall is perpetually wet due to sone exterior problem like ground level for instance).

Also on the molding front, I’ve stayed in straw bale Airbnb’s in wet central wales (internally and externally plastered / rendered in lime of course + big roof overhangs), and they seemed to be fine.

 

[Mikeyboy7]

Also on the molding front, I’ve stayed in straw bale Airbnb’s in wet central wales (internally and externally plastered / rendered in lime of course + big roof overhangs), and they seemed to be fine.

Cheers , how much are you paying for the cork ? I was quoted €65 plus. For 250litre bag

 

[aockenden]

Cheers , how much are you paying for the cork ? I was quoted €65 plus. For 250litre bag

Yeah that’s about the same I’m paying from Mike Wye. I bought in 75 liter bags for 20 quid per bag including VAT. Not including delivery.

Careful on the suppliers though as I bought a first test batch from a supplier that was actually based in Poland and ended up having to pay an extra import duty.

 

[Mikeyboy7]

Yeah that’s about the same I’m paying from Mike Wye. I bought in 75 liter bags for 20 quid per bag including VAT. Not including delivery.

Careful on the suppliers though as I bought a first test batch from a supplier that was actually based in Poland and ended up having to pay an extra import duty.

Brilliant, thanks for all your advice , I’m going to give your recipe a go at the weekend

 

[Mikeyboy7]

I assume this is directed at me? The final recipe I settled on which I’ve been using consistently for the last month is:

1.25 buckets of well drained lime putty (made from either quicklime or hydrated lime), not aged more than a day or two typically.

0.25 buckets of NHL 3.5 powder.

1 bucket of granulated cork.

1 bucket of hemp shiv.

Water until sticky but not sloppy or runny. I want it to ball up into slimy snowballs in my hands. I actually just slapped another batch on our second bedroom’s wall this morning. See pic.

Also, nothing is hot mixed. I no longer believe the stories about the value of hot mixed mortars, all a bit too esoteric and “magical” for me to believe in, especially when I’ve found no benefit vs mixing cold with pre-slaked cold putty. Plus I got sick of burning my cork + hemp and melting through plastic buckets.

View attachment 12583

Just a question, what’s your procedure for make the lime putty

 

[aockenden]

Just a question, what’s your procedure for make the lime putty

Good luck this weekend! I’ve made lime putty using both quicklime (calbux) and hydrated lime (limbux). As long as they are fresh bags they will both make a fine putty. Hydrated lime is slightly more expensive per unit of yielded putty but is MUCH easier and safer to work with than the quicklime, so I would recommend that. Just dump the powder in a big bucket, add a bunch of water, stir it, top up some extra water and then let it settle out for a couple days so the lime gets denser and less watery as a layer on the bottom with the excess water floating ontop.

 

[Mikeyboy7]

Good luck this weekend! I’ve made lime putty using both quicklime (calbux) and hydrated lime (limbux). As long as they are fresh bags they will both make a fine putty. Hydrated lime is slightly more expensive per unit of yielded putty but is MUCH easier and safer to work with than the quicklime, so I would recommend that. Just dump the powder in a big bucket, add a bunch of water, stir it, top up some extra water and then let it settle out for a couple days so the lime gets denser and less watery as a layer on the bottom with the excess water floating ontop.

no problem,

 

[Mikeyboy7]

Good luck this weekend! I’ve made lime putty using both quicklime (calbux) and hydrated lime (limbux). As long as they are fresh bags they will both make a fine putty. Hydrated lime is slightly more expensive per unit of yielded putty but is MUCH easier and safer to work with than the quicklime, so I would recommend that. Just dump the powder in a big bucket, add a bunch of water, stir it, top up some extra water and then let it settle out for a couple days so the lime gets denser and less watery as a layer on the bottom with the excess water floating ontop.

First wall done thanks for all your advice

 

[aockenden]

First wall done thanks for all your advice

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Duddddeeee, most excellent! Congrats. It looks legit. I hope you find the results as beneficial as we have.

On our side, we’ve been working on applying the basecoat in my Son’s bedroom this weekend (including behind his built-in wardrobe). Only the inside of the window reveal left to do for the basecoat now.

 

[Mikeyboy7]

Duddddeeee, most excellent! Congrats. It looks legit. I hope you find the results as beneficial as we have.

On our side, we’ve been working on applying the basecoat in my Son’s bedroom this weekend (including behind his built-in wardrobe). Only the inside of the window reveal left to do for the basecoat now.

View attachment 12658

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View attachment 12660

Keep up the good fight

 

[Mikeyboy7]

Duddddeeee, most excellent! Congrats. It looks legit. I hope you find the results as beneficial as we have.

On our side, we’ve been working on applying the basecoat in my Son’s bedroom this weekend (including behind his built-in wardrobe). Only the inside of the window reveal left to do for the basecoat now.

View attachment 12658

View attachment 12659

View attachment 12660

Hope you’re keeping well , Ive started on another room on Saturday, this time with quicklime only and cork & hemp , slaked the quicklime for around 2hrs and then added the hemp & cork !!
had a look earlier today & it had lots of cracks and it didn’t seem to be stuck to the wall especially around the edges, would you know the reason for this , I did wet the wall good , but I didnt scratch it , I don’t want it to fall off in a few months , probably should have stuck with the hydrate lime