Purity Limewash FAQ

Frequently asked questions about Purity Limewash Paint

What is limewash paint?


Our limewash paint is a true lime wash. That is to say, it is a pure mineral formulation. Purity Limewash Paint is a modern composition of an ancient paint formula made from crushed limestone. In the process, the crushed stones are burned and then water is added to the lime. The material is aged in water. Pigment is then added for color and when the limewash paint is applied to a surface it begins the process of carbonation. In this process, the limewash absorbs carbon dioxide from the air and uses it to turn back into the limestone structure! This is what we call the curing process and it takes days or weeks even, depending on the moisture content of the surrounding air and if the surface is misted during the process.


Can I apply limewash paint to difficult to adhere or glossy surfaces?


You can after proper preparation. If the surface is glossy or a known difficult surface to apply paint, you will likely need to apply a “bridging primer” before applying Lime-Prep mineral primer. There are several readily available products that will work for this application. The “bridging primer” should be a primer that is intended to prime “difficult to adhere to” surfaces and is suitable for a water based paint coating over the primer. After applying the bridging primer, you will be able to apply the Lime-Prep Primer and will then be able to paint with Purity Limewash. Please feel free to contact us if you'd like advice with prep.


Coverage rates


Coverage rates will range depending on the porosity of the surface. Generally, a gallon of Purity Limewash will provide approximately 250-350 feet of coverage. Coverage rates are determined using two coats as a standard. If coverage rates are much lower than expected, the surface may be absorbing too much material and should be misted more thoroughly to reduce absorption rates.


Why do the instructions say to spread the limewash as far as it can be spread naturally? Won’t a good thick application provide more consistent results for color and finish?


Limewash is not like a standard film-forming paint so a thick application is the opposite of what is required with this finish. We want the limewash to absorb into the surface and create a beautiful finish but it will perform poorly if it's applied too heavily. Limewash painting is more like staining and less like traditional painting. A thick coating will weaken the finish and can cause cracking of the limewash finish and durability issues. Always apply thin!


Why do I need to mist surfaces with water during limewash application for best results?


Limewash absorbs into the surface that it is being applied to (the Lime-Prep Primer serves as the absorbent material if you are not painting on masonry or unfinished wood) This is the method by which it keys or grabs onto your material. Controlling absorption is what you are looking for. You don’t want to overly wet your surface because then the limewash will not be able to absorb adequately and may become diluted. For some interior applications, wetting the surface is not necessary but special attention must be paid to spreading the limewash paint as far as possible.


The instructions say to mist the surface with water while limewash painting. What is the best tool for that?


You can use something as simple as a spray bottle on mist setting but we like to use a compact hand-pump sprayer that you can purchase inexpensively at a hardware store.


Roller or sprayer applications


While we don’t recommend roller or sprayer applications in most circumstances, some production level applications may benefit from using specialized methods or equipment for faster applications. Please contact us if you have any questions for a larger project and are considering application methods.


How will sealer affect appearance and performance?


Interior applications:


Our interior sealer is a very flat finish with exceptionally low sheen. It allows the surface to be wipeable. There will be a slight sheen increase from using sealer. If you want the surface as flat/matte as possible, adding a sealer may not be desirable. Another benefit of not sealing is that you can touch-up with no prep (if you need to touch up after applying sealer, you will need to apply Lime-Prep primer to the surface before completing the touch-up application). Finally, a consideration is that with deeper colors, the sealer can lighten the appearance of the color. Always test in an inconspicuous area before applying to the whole surface.


Exterior applications:


The application of exterior sealer is to “freeze” the limewash finish wear level. With no sealer applied, limewash paint on exterior surfaces will slowly wear and will need to be refreshed from time-to-time. Refreshing limewash every couple or few years can be a fairly quick process without much preparation needed and is the traditional method of maintaining a limewash finish. For those who would like to reduce the maintenance frequency and also maintain the surface finish level to not allow wearing, we recommend applying exterior sealer after the limewash has cured. Usually a week is adequate.


Does Purity Limewash Sealer make walls washable?


The sealer allows walls to become wipeable but we would not consider it a washable surface. If you want a more washable surface, the exterior sealer will be a more durable finish. Limewash paints do not create a rubbery film as acrylics do so they do not allow for the same level of scrubbing without damage. An alternative care method is to not seal the walls and occasionally apply a new coat of limewash as it does apply rather quickly compared to standard paints.


Do I really need Lime-Prep Primer?


If you are not applying to bare/unfinished/non-sealed masonry, wood, or plaster, you will need to apply Lime-Prep Primer to create a compatible surface for the limewash to "grab" onto. The proper primer will also help with producing a more accurate color finish.


How do I do touch-ups?


Limewash creates a somewhat uneven color and patterned appearance so touching up small areas can often work quite easily. Make sure that if you did seal, that you apply Lime-Prep at your touch-up area before applying limewash. It is a good idea to test your method in an inconspicuous area before touching up in a more visible location. If you have questions, you can always contact us for tips.


Are all your products water-based?


Yes, all of our products are water based and are water-clean-up.


What's the difference between exterior and interior sealers?


Our interior sealers are all formulated to have a lower sheen level for super-matte finishes but do not have the durability required for exterior applications. Exterior sealers are more durable but have a higher sheen level.


Can I dilute Purity Limewash to use as a “wash” finish for brick or wood?


Yes! One or two applications of various dilution ratios will create a translucent finish. Purity limewash can be diluted with water up to 300 percent of volume to create a nearly transparent wash effect. This is a standard dilution ratio for wood-wash finishes.


Is Purity Limewash heat resistant or fireproof?


Our primers and sealers are not rated for high heat and cannot be used for high-temperature environments. All Purity Limewash paint is non-flammable and is a “heat-resistant” finish. This means that it will not catch on fire, however, it is not designed to be exposed to open flame or high heat specifically. You can use it indirectly close to flame but it should not be directly exposed. 


What about custom colors?

While we do not offer custom color matching, mixing two or more colors can create a custom blend and all Purity Limewash colors are all compatible for blending to create custom colors.