I’m afraid this is really not great advice, as it isn’t true. Limewash is as good as you can get. F&B claims good values, but mostly in a human breathability basis, and its moisture management is not great, not terrible, but there are better paints out there, before you get to distemper. But none of them come close to genuine limewash - there are companies who sell ‘limewash’ for exorbitant prices, which sadly isn’t true limewash and probably performs on a par with F&B for example.
- Thread starter Jblakes
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I have had big issues with Earthborn clay on a thick external lime / stone wall - mould spots all over the external walls - like a circular blotchy pattern everywhere. This isn't black condensation mould that wipes off although we do get a bit of that where there is no airflow.
We experienced the same as Steveb. We used it over our lime wall which had been plastered and lime washed for five years, after fancying a bit of colour. After 3-6 months from painting, it developed little spots of what can be described as fine droplets of oil marks. I had to strip off the Earthborn paint with a very sharp wallpaper stripper. sanding made the surface like glass and extra hard so hence the brutal tool. It took a few mm’s of lime with it but it has been fine since. My view is the paint is not suitable for certain areas like ours. Our wall is a double skin cob and stone wall with a French drain behind and a foot of large shingle , maybe something to do with it or we got a dud tin of paint? Mystery to me!
We experienced the same as Steveb. We used it over our lime wall which had been plastered and lime washed for five years, after fancying a bit of colour. After 3-6 months from painting, it developed little spots of what can be described as fine droplets of oil marks. I had to strip off the Earthborn paint with a very sharp wallpaper stripper. sanding made the surface like glass and extra hard so hence the brutal tool. It took a few mm’s of lime with it but it has been fine since. My view is the paint is not suitable for certain areas like ours. Our wall is a double skin cob and stone wall with a French drain behind and a foot of large shingle , maybe something to do with it or we got a dud tin of paint? Mystery to me!
The few spots I have had went shiny and hard if I tried to rub them off too - totally unlike the same paint everywhere else. Very odd.
, probably give earthborn paint a goWell, without having measured the vapour permeability of the various paints myself, being without the necessary equipment, I have to go on figures quoted in documentation of various sorts. Usually paint permeability is expressed as 'equivalent air thickness' (sd, in metres). Highly 'breathable' paints have sd values less than 0.1. F&B estate emulsion has a value (according to the manufacturer) of 0.01, which is the same as they quote for their limewash and their distemper, other manufacturers quote the same value for these materials. Earthborn quote 0.03 for their claypaint. Keim quotes 0.01 for most of their mineral paints and in their tests they report that surfaces painted with these paints lose moisture as fast as limewash (or as near as makes no difference) and limewash loses moisture nearly as fast (as near as makes no difference) as an unpainted surface. From these 'facts' I draw the conclusion that it makes no real difference whether you paint your plaster in F&B estate emulsion, Keim mineral paint or limewash. The interesting thing about F&B is that they recommend using distemper or limewash on new lime plaster and not estate emulsion - the reason being that they recommend using the primer for estate emulsion and the primer has low breathability (sd = 0.5). Of course, everyone is free to disbelieve manufacturer's measurements - Peter Ward, for example, doesn't believe that mineral paints (like Keim) are breathable enough for old buildings. But has he measured their breathability - I doubt it. Numbers are better than opinion in my view, but then I've been trained that way.
That is the best option by far, and super cheap. Bit of a slow process to apply, but worth it…
However, to answer your question - get a tub of mature lime putty, not bagged powder. There’s a process to mixing the right consistency, it’s not as simple as ratios, more a final consistency. Then application is an art. And a repetitive one. You’ll need the right brush, application process. And at least 3 coats to build up the layers.
Due to pallet delivery costs, you’ll want to find a local supplier for the putty. But give Rose of Jericho a call to discuss your needs - they’re brilliant and can talk you through the process, and they do sell putty if you’re buying enough other things to justify the delivery costs. If you choose to pigment your lime wash, that opens up some more options too…
This just popped up on a feed… thought it may be of interest. The pointers at the end are great.
Pink is relatively easy to achieve in the spectrum, final colours will always be pale as the pigment can’t be too much of the percentage.
www.limestuff.co.uk
Pink is relatively easy to achieve in the spectrum, final colours will always be pale as the pigment can’t be too much of the percentage.
How to apply Limewash | What is Limewash used for | Lime Stuff
Traditionally LIMEWASH was the principal finish applied externally and internally to historic buildings, quite often applied directly to the masonry or brickwork and more commonly to pre-applied lime
www.limestuff.co.uk
In essence yes, in practice, well, practice, practice, practice…! When wet the colour will be much darker than it dries. There’s lots of good reading out there on the process and quantities, you build colour in layers, not by adding too much pigment and upsetting the balance of the limewash itself.
It’s test and learn… just make sure you have enough of each mix to cover the entire area for each cost to keep consistency!
I wouldn't.
If you search, you'll find as many articles suggesting spraying with a milk based product to encourage rapid growth of moss and lichen...
Traditionally adding tallow to a hot quicklime mix can increase water repellency (equally reducing breathability).
If you search, you'll find as many articles suggesting spraying with a milk based product to encourage rapid growth of moss and lichen...
Traditionally adding tallow to a hot quicklime mix can increase water repellency (equally reducing breathability).
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I have heard of a number of different additives that purportedly enhance the durability of lime wash and tried adding a little linseed oil after reading one such suggestion. At the time I was lime washing all the infill panels of this old pile and I have to admit that those painted with the lime/linseed wash have better resisted the weather and there has been little flaking and no tell-tale 'dusting' associated with these. As I recall, there was no explanation as to why this may work but I guess the oils add support to the bonding of the lime molecules as the water evaporates off to produce a more resilient final finish. Maybe someone more qualified than I may be able to confirm/refute the above but among other things I have heard of include Tallow or Tally (Mutton Fat).
[Noj beat me to it here as I was about to add that the fats in milk/fromage frais may do the same job but I would worry that these may attract mosses and lichens.
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Just a quick addition. I have noted that since lime-washing the infill panels here they have resisted the growth of lichens which were an annual problem on the North side of the house. Much better now so less time up a ladder cleaning the darned stuff off.