What is limewash?
Limewash is a simple paint type which is literally just made from natural lime and water. Lime wash is fundamentally made from naturally occurring limestone that has been crushed, burned and then mixed with water to create a putty. This putty is then traditionally aged and then thinned with water. Some limewash can have additives in them, and some not. Pigments are used for colour, using what are called alkali resistant ‘lime fast’ pigments, which are often made from natural earth pigments such as metal oxides. Limewash is a very traditional paint that has been used for more than a thousand years in many countries around the world. It was a staple finish to your Roman home. Limewash can be used for many applications both inside your house and for the exterior. Limewash is traditionally used on lime plaster and render, but can also be used over brick and masonry than has also been covered or repointed with mortar made from lime.
What Limewash colours are available?
It’s interesting to know that certain limewash colours are often quite associated with certain regions of the country, for instance pinks are often seen in Suffolk, England and Orange (often quite vibrant) can often be found in the Scottish Lowlands, Lothians. Traditionally lime-washes would not be the brilliant white that you see now, as before they would have contained impurities, which would result in the colour being slightly off white. It is possible to add natural earth colours to limewash to achieve a selection of off white colours. Pigments are generally mixed into the base limewash at a ratio of 20 to 1.
What is the difference between limewash and whitewash?
You’ll find that the terms ‘whitewash’ and ‘lime wash’ are used in the same way, However it has been noted that whitewash is often used as a term for poor quality limewash (or white distemper).
What are the physical attributes of limewash, and what does limewash look like?
First of all, limewash is a very natural white colour. It has a certain look to it that is hard to describe that is best to actually see with your own eyes. It has a beautifully natural and matt finish – which even to the untrained eye looks much better than a modern house-paint. Fundamentally limewash is made from tiny crystals, so as you would expect these reflect the light very differently to a plastic based house paint. Limewash does noticeably get darker when it is wet, as often pointed out by the professionals it’s a good way to see where the problem areas of your walls are, by the amount of moisture it retains (and shows as a darker patch) as the wall dries out again. Limewash can be spotted by the medium toned colour, and non uniform appearance. The paint erodes gently (rather than peeling).
Where can I use limewash?
Limewash is suitable over lime plaster and lime render, as well as earth walls, limestone, older limewash and even timber. Although it can be applied to cement render, and surfaces that have emulsion or plasterboard, it doesn’t adhere to nearly as well.
What should you not paint with limewash?
Limewash is not suitable for painting surfaces such as flint and hard brick, and also it would be advised not to use as a first time finish on sandstone.
What are the benefits of using limewash? Is limewash breathable?
Lime wash certainly is breathable, about as breathable as it gets. It is also as standard virtually VOC (Volatile organic compounds) free, which is much better for your indoor environment and a much healthier alternative to modern house paints filled with chemical nasties. This is especially important for older buildings that need to need to be able to breathe. Limewash ages well, and offers subtle colour changes which are quite attractive, it certainly looks amazing over time and stands up very well (better than modern paints in my opinion)
The PH level is also an advantage of limewash (pH 12-13), as the alkalinity does deter invaders such as the wood boring beetle and almost offers a kind of sterilisation for walls. As it is easy to manufacture and made from simple ingredients, it means the finish is cheap and chemical (solvents) free. The high pH level of lime means that tiny micro-organisms don’t survive, which can make the paint hypoallergenic. It also can help remove odours in the air, due to the chemical makeup which has the added bonus that it can improve indoor air quality. Limewash is slightly flexible, which can help to deal with the natural movement in a building, which reduces cracking.
- Natural, solvent free, odour absorbing and hypoallergenic
- Bacteria resistant
What are the disadvantages of using limewash?
Colour matching between different paint jobs and batches is very difficult due to the natural ingredients. If you are in a fast drying environment, it’s not ideal, as it does need to be able to dry in it’s own time for best results (due to its own chemical reaction) rather than just a solvent evaporating.
Is limewash dusty?
If you’re finding your limewash dusty, it usually means that it has not been applied correctly. It should not rub off when applied well. If you do find it rubs off, it’s probably due to bad preparation with your ordinary lime, or perhaps that it has been applied too thickly. Also, without adequate dampening down before limewashing can mean the limewash dries out too fast. Common mistakes when applying limewash include:
- Limewash dry & powdery: Dried too fast. Spray with water and re-coat.
- Limewash not absorbed: Unsuitable non porous surface.
- Limewash patchy: Not mixed well enough. Mix the next coat better!
- Limewash dries too quickly: Remove flakes and damp back down.
- Make sure there is no chance of frost for a few weeks after you have finished.
How do I make limewash?
By diluting lime putty (to the consistency of milk) will be enough to produce limewash. If using pigments it is advised to pre mix pigments with hot water. Traditionally lime putty was created from quicklime, but these days it’s just bought pre-made for convenience. By preparing putty from ordinary non hydraulic bagged lime can often result in poor finished limewash. You really can make your own limewash if you really want to, you can by the lime putty (hydrated lime) and then mix with water. To make limewash you need equal parts putty to water by volume. Ideally add water until you get the consistency of single cream, or Oatly cream if you’re vegan ;)
Use up to 1 part pigment to 10 parts limewash. Unpigmented limewash is almost clear when applied, and turns white when dried / cured.
Does limewash contain binders?
Limewash often contains additional binders to help with improve water shedding and / or adhesion – but it is not always a good choice. Common traditional examples of additives would be tallow or raw linseed oils, but both of these reduce breathability. Tallow, as with casein, can support mould growth.
How often do I apply or re-apply limewash?
Traditionally limewash is renewed every five years. Surfaces are just brushed brown and cleaner, check for mould growth and removed if needed. The surface will then be dampened, and then a thin first coating of fresh limewash will be worked in with a large and textured brush. It would be ideal for a further 3 or 4 coats after this. Gloves and eye protection are always required. As mentioned, it’s important that a long haired masonry paintbrush is used, that creates feathered strokes.
How do I clean limewashed walls?
We don’t recommend you do this, and to be honest it’s just not needed! Just paint over the main wall area with a thin coat.
Quickfire limewash questions:
- Is limewash cheaper than paint? Yes, almost always.
- Can limewash be removed? Yes, use a stiff brush and a jet washer!
- Can I limewash over paint? Not if you’ve used a plastic paint, no.
- How many coats of limewash do I need? We advise to have 3-4 coats of limewash.
- Is limewash waterproof? Yes, it’s both waterproof (within reason!) and breathable
Which lime based paints do you recommend?
Interior Lime Based Paint: We love the Graphenstone Ecosphere for interiors, this is a traditional lime paint, with the extra addition of natural graphene which allows this paint to adhere to most surfaces including existing non lime paints. Check out Graphenstone Ecosphere here
Exterior Lime Based Paint: We love the Graphenstone Biosphere for interiors, this is a traditional lime paint, with the extra addition of natural graphene which allows this paint to adhere to most surfaces including existing non lime paints. Check out Graphenstone Biosphere here