Breathable emulsion paints?

[Stueeee]

I know there are some people who live in old places on this forum so am hoping for suggestions on a suitable paint. We live in a Victorian place where the (solid) back wall of the house gets all the weather, I'm in the process of redecorating and would like to use a breathable (microporous) emulsion paint on the walls to prevent any issues with impervious Vinyl etc. paints lifting after weeks of biblical rain.

From a number of Google searches it appears that "Earthborn" paints are the only ones that advertise this feature, needless to say, they're excruciatingly expensive. Any suggestions for alternatives (or experiences with Earthborn paints) welcome.

TIA, Stuart.

 

[armalites]

These people specialise in lime and eco products and list quite a few breathable products, they are very helpfull and worth a phone call.

https://www.lime.org.uk/products/paints-oils-waxes/internal-preparation.html

These kind of products are always going to look massively expensive when compared to a 10L bucket of trade emulsion.

There must other products out there as I've seen it mentioned on DIY SOS where they are painting over plaster with 24hrs and say they used special paints

 

[malcolm]

I've used the Earthborne clay paints. About 2.5 times the cost of Dulux emulsion but the coverage is much better so you use half as much. I have noticed a lot of things advertised as breathable that aren't really - stuff that breathes just a little is often sold as breathable. Worth a look around the Period Property forum - they talk a lot about breathable paints.

 

[julianf]

Lime firm did some work on a house across the road from me. They painted in a breathable non limewash finish. I think it required two coats on the render, both done on the same day...

Irritatingly I can't recall the name, but this isn't a complete waste of them, as I'm pretty sure they said Mike wye would sell it.

Might be worth giving them a call. Near holsworthy in Devon, but easy enough to find on Google.

 

[brightspark]

are you talking about inside emulsion paint ???or an external paint , if inside just use none vinyl contract paint that's breathable and used on newly plastered walls or ones that have been damp proofed

 

[Stueeee]

Thanks for the replies so far. This is for inside decoration. From looking at google results all the paint companies blether on about their marvellous colours and finishes; but even the data sheets are pretty well information free as to the actual properties of whatever paint they're selling.

 

[brightspark]

as long as the paint is vinyl free the wall can breath. all new houses are painted with it and its used on walls that get damp proofed and its no more expensive than vinyl painthttps://www.screwfix.com/p/no-nonsense-trade-bare-plaster-paint-brilliant-white-10ltr/51004?tc=RB4&ds_kid=92700030936902299&ds_rl=1241687&ds_rl=1245250&ds_rl=1243321&ds_rl=1245250&ds_rl=1249481&gclid=EAIaIQobChMItq-d47GV6AIVGeDtCh0tSwGeEAQYASABEgJxk_D_BwE&gclsrc=aw.ds Shipley paints mix the colours or manor coatings

 

[Blake's 7]

Hi there Stuart,

I'm in the process of renovating an old stone farmhouse which will be plastered inside and out with lime mortar and have had advice from someone who specialises in this area.

When I looked into using breathable paints I found them to be quite expensive so based on what this consultant told me I now intend to use a limewash on the internal walls to which I will add pigments to give me the colours I want.

Firstly, To get a white limewash (whitewash) he told me to use a 1:1 mix of White Rhino Hydrated Lime with an equal amount of Natural Hydraulic Lime (NHL 3.5). The NHL 3.5 will give it a strength - whilst retaining its breathability - which it wouldn't otherwise have were I to only use the White Rhino lime on its own. For colours other than white you can forego the use of the White Rhino lime and just add the pigments to the NHL 3.5. When mixing your washes you should aim for a consistency of a little thicker than water.

Hope this has been of some help to you and given you a few ideas of how to proceed.

 

[Gareth J]

Hi there Stuart,

I'm in the process of renovating an old stone farmhouse which will be plastered inside and out with lime mortar and have had advice from someone who specialises in this area.

When I looked into using breathable paints I found them to be quite expensive so based on what this consultant told me I now intend to use a limewash on the internal walls to which I will add pigments to give me the colours I want.

Firstly, To get a white limewash (whitewash) he told me to use a 1:1 mix of White Rhino Hydrated Lime with an equal amount of Natural Hydraulic Lime (NHL 3.5). The NHL 3.5 will give it a strength - whilst retaining its breathability - which it wouldn't otherwise have were I to only use the White Rhino lime on its own. For colours other than white you can forego the use of the White Rhino lime and just add the pigments to the NHL 3.5. When mixing your washes you should aim for a consistency of a little thicker than water.

Hope this has been of some help to you and given you a few ideas of how to proceed.

Interesting. What's the difference between the White rhino and NHL? Obviously different manufacturers will be different but is there something fundamentally different? Hydraulic Vs Hydrated maybe?

 

[Blake's 7]

Interesting. What's the difference between the White rhino and NHL? Obviously different manufacturers will be different but is there something fundamentally different? Hydraulic Vs Hydrated maybe?

Sorry for not replying a bit sooner.

When limestone is burned in a kiln quicklime is produced, slaking this quicklime with water produces hydrated lime. Hydraulic means that the NHL will set even under water. There are three different grades of NHL - 2, 3.5 and 5. These grades refer to how hydraulic the lime is with 2 being the lowest grade, slowest setting, and softest of the three. The 3.5 grade is what is usually used for plastering walls and stonework in old farm buildings and the like. Grade 5 is what buildings such as lighthouses would be plastered with as it produces the hardest mortar and therefore the least impervious to moisture of the three grades. For mortar, ordinary builders sand is too fine and the final product is too weak. I'm using a sharp sand graded down from 5 mm and mixed with NHL 3.5 at a ratio of 1 lime to 2.5 of sand. Maintaining this ratio accurately is important as the idea is to have just enough lime in the mix to fill the voids between the grains of sand.

When I mixed the hydrated lime and the NHL 3.5 together the colour of the latter dominated the mixture and I couldn't really tell from looking at it that there was white hydrated lime in it, but after it had dried on a section of wall I used as a test area it came up a lovely, soft white colour.

 

[Gareth J]

Sorry for not replying a bit sooner.

When limestone is burned in a kiln quicklime is produced, slaking this quicklime with water produces hydrated lime. Hydraulic means that the NHL will set even under water. There are three different grades of NHL - 2, 3.5 and 5. These grades refer to how hydraulic the lime is with 2 being the lowest grade, slowest setting, and softest of the three. The 3.5 grade is what is usually used for plastering walls and stonework in old farm buildings and the like. Grade 5 is what buildings such as lighthouses would be plastered with as it produces the hardest mortar and therefore the least impervious to moisture of the three grades. For mortar, ordinary builders sand is too fine and the final product is too weak. I'm using a sharp sand graded down from 5 mm and mixed with NHL 3.5 at a ratio of 1 lime to 2.5 of sand. Maintaining this ratio accurately is important as the idea is to have just enough lime in the mix to fill the voids between the grains of sand.

When I mixed the hydrated lime and the NHL 3.5 together the colour of the latter dominated the mixture and I couldn't really tell from looking at it that there was white hydrated lime in it, but after it had dried on a section of wall I used as a test area it came up a lovely, soft white colour.

Cheers. Did a bit more reading since and makes sense somewhat. Although I can't actually find out how hydrated lime differs from hydraulic lime chemically. Just that hydraulic is made using "different" limestone which gives it better wet cure properties.

There's a lot of woo and evangelicalism surrounding the use of lime/lime mortars. Those who believe, often say it's the best thing ever and it'll cure all of the world's ills with little to no actual reason/evidence.
However, it does interest me and I appreciate there are definite reasons to use it over cement in lots of situations.

Have been experimenting with whitewash made with cheap hydrated lime, which works well as an outhouse/workshop level wall whitener. Also been using it in combination with a bit of cement for rough repair jobs which looks reasonable. Not much point messing about with hydrated for anything more important though if there's an important structural difference using hydraulic.

 

[jenki]

Ty Mawr Lime provide a lot of info on their website may be worth contacting.
If mixing lime please wear suitable PPE particulary eye protection and long sleeved gloves and beware of using plastic mixing containers some of the reactions produce significant heat. I think the modern limes may be safer.
In the 80's my then wife and myself made our own limewash long before the current hype about lime fortunately she is a chemist and knew about the the risks I remember adding Linseed oil to the mix. IIRC the Society for the Protection of Ancient Buildings SPAD had information sheets at the time, pre internet.
As an aside pink limewash was made in West Wales by adding blood from the slaughter house to the mix in olden times apparently.

 

[mtt.tr]

Definitely wear a mask lime dust is bloody horrible, burns terribly.

Nhl is a wonderful product and easy to use, a good friend is a historical housing specialist and often suggests nhl which is why I used it. Personally i think it snobbery

 

[Blake's 7]

..... Have been experimenting with whitewash made with cheap hydrated lime, which works well as an outhouse/workshop level wall whitener. Also been using it in combination with a bit of cement for rough repair jobs which looks reasonable. Not much point messing about with hydrated for anything more important though if there's an important structural difference using hydraulic.

The consultant whom I mentioned earlier has told me that whitewash when used externally is a 'sacrificial coating' and that if applied properly in several layers would last around ten years. I'd imagine therefore that internally it should last a lot longer.

I know the guy who did the lime plastering work pictured below, the next time I see him I'll ask about hydrated lime, etc and post back here afterwards.

 

[Blake's 7]

Definitely wear a mask lime dust is bloody horrible, burns terribly.

Nhl is a wonderful product and easy to use, a good friend is a historical housing specialist and often suggests nhl which is why I used it. Personally i think it snobbery

Alkaline burns are much more severe than acidic burns. Alas, I know this only too well.