What is limewash, how do you apply it, and how much does it cost?

Limewash is a mineral paint made from slaked lime, water, and natural pigments that gives walls a soft, matte, and textured finish with subtle movement. A gallon of ready-made limewash costs about $125 to $140 in Canada and covers 250 to 350 square feet in two coats.

This guide explains what limewash is made from, how it differs from regular paint, its pros and cons, common misconceptions, which surfaces it suits, and how to apply it. It also covers a basic DIY recipe, limewashing brick, and what a painter charges.

What is limewash?

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What It's Made From

Limewash is made from slaked lime, or calcium hydroxide, mixed with water and natural pigments. As it dries, the lime absorbs carbon dioxide from the air and hardens into calcium carbonate, giving it a mineral composition and its hallmark texture.

It's also a historical finish. In some old Quebec stone houses, restorers have found up to 28 layers of white limewash on interior walls, applied until the late 19th century.

How It Differs from Regular Paint

Limewash soaks into porous surfaces instead of forming a plastic film on top. That makes it breathable, letting moisture escape from masonry walls. It has low opacity, so it builds colour in several thin coats and leaves depth and movement rather than a flat, uniform finish. Ready-made limewash products sold in stores often include an added binding agent to improve adhesion, so check the product's data sheet before buying.

Air Lime vs. Hydraulic Lime

Limewash and lime paints are made with air lime, which hardens on contact with air. Hydraulic lime, which sets with water, is mainly used in mortars and renders, not in limewash.

The Pros and Cons of Limewash

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Advantages

• Texture and depth: The matte, mottled finish gives walls an aged, antique whitewash aesthetic that latex paint can't reproduce.

• Breathability: It lets water vapour pass through, which suits old masonry walls, plaster, and preserved historic buildings.

• Softens the look of minor flaws: Its mottled texture visually blurs slight irregularities, though it doesn't fill cracks or dips.

• Natural ingredients: Its mineral composition releases very few volatile organic compounds compared with many conventional paints.

• Mould resistance: Its high pH helps limit mould growth.

Disadvantages

• Harder to apply: The finish depends on technique, and each wall must be painted in one go to avoid lap marks.

• More fragile surface: Limewash is porous and can stain, and it's less washable than latex paint.

• Requires careful preparation: Limewash goes on in thin coats and can't bridge cracks or hide poorly sanded patches, which may even stand out once it dries.

• Less predictable results: Limewash goes on much darker and dries significantly lighter, and the final colour varies with humidity and coat thickness.

• Caustic when wet: Wet lime can irritate skin and eyes, so gloves and eye protection are essential.

• Weathering outdoors: Exterior limewash weathers naturally over time, and areas exposed to wind-driven rain may need touch-ups.

Which surfaces can you limewash?

Limewash bonds naturally to porous, mineral surfaces. On other surfaces, a suitable primer is needed.

• Brick and stone: Ideal surfaces, indoors and out, once clean and lightly dampened.

• Plaster and mineral render: Excellent, since they're porous.

• Concrete: Suitable if it's clean and free of grease or contaminants; new concrete must be fully cured, at least 28 days.

• Unpainted drywall: Drywall paper and joint compound absorb differently, which can make the joints show through, so a primer designed for limewash is needed.

• Painted interior walls: Limewash won't grip a smooth, non-porous surface, so a limewash primer is required.

• Raw wood: Traditional whitewash was used on barns and fences, but it wears quickly on wood and isn't a long-lasting finish.

Historically, limewash was valued for practical uses as well as looks: it was applied in rural dairies and farm buildings for its hygienic properties, and on glasshouse roofs for shading.

Common Misconceptions About Limewash

• "All limewash is the same": Pure slaked-lime limewash differs from hybrid products that add acrylic or other binders. Hybrids are easier to apply but less breathable, so read the label if authenticity matters.

• "It's toxic": Limewash contains no harmful solvents and has no strong chemical smell. Its high pH makes it corrosive while wet, so protect your skin and eyes, but once cured, it's safe.

• "It's a fungicide": It isn't a fungicide product. Its high pH discourages mould growth, but it won't fix an underlying moisture problem.

• "One coat is enough": Limewash is designed to go on in several thin coats. Its low opacity is what creates its depth and texture.

• "It works on any surface": It needs a porous surface or a suitable primer. On glossy or previously painted surfaces, it won't adhere without one.

• "It doesn't need any protection": In wet or high-traffic areas, a breathable protective topcoat compatible with lime helps resist stains.

How to Apply Limewash

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Step 1: Prepare the Surface

Clean the wall to remove dust, dirt, and residue, using a suitable cleaner if there's algae or moss outdoors. Patch holes and cracks, then protect the floor with a drop cloth, since limewash stains are hard to remove.

Step 2: Apply a Primer if Needed

On painted walls, unpainted drywall, or any low-porosity substrate, apply a primer designed for limewash in an even coat. For darker limewash colours, choose a primer tinted close to the final colour, and let it dry as directed by the manufacturer.

Step 3: Apply the Limewash

Mix the limewash as directed and stir it often while working, since particles settle. Apply it with a natural-bristle brush in random, criss-cross strokes, working each wall section in one go from the same container to avoid lap marks. Limewash has a short open time, so work steadily. A second coat adds depth and the characteristic finish.

Step 4: Let It Dry and Protect It

Limewash usually dries within hours but keeps hardening for several weeks, so avoid cleaning the wall during that time. Afterward, dust it for routine care, or wipe gently with a lightly damp cloth without scrubbing. In damp or high-stain areas, a breathable protective topcoat compatible with lime improves resistance.

Applying Limewash Outdoors

Outdoors, apply limewash in mild weather, out of direct sun and with no rain forecast for the following days, and never when frost is possible. Damping down the masonry lightly before application keeps the limewash from drying too fast and cracking.

How to Limewash Brick

Limewashing exterior brick has become popular for softening red brick into an aged, whitewashed look. Clean the brick first, and repair cracks or damaged mortar. Then dampen the surface and apply the limewash with a large masonry brush, working it into the joints. While it's still damp, you can wipe or spray some of it off for a more distressed finish that lets the brick show through.

Because brick is very porous, it absorbs more limewash than a primed wall. Test a small area first, and keep in mind that the finish will weather naturally over the years. For a full house façade, a painter experienced with limewash will get a more even result.

A Basic DIY Limewash Recipe

A homemade limewash is made from slaked (hydrated) lime, water, and natural pigments:

Pour the lime into the water slowly while mixing to prevent lumps, then add the pigments diluted in a little water. Pigments rely on the lime to bind to the wall, so don't exceed the recommended proportions, or the finish may chalk and dust once dry. A natural additive such as casein can be added to improve adhesion. The more porous the surface, the more it absorbs, so adjust the water and always test a small area first.

Lime is caustic: wear gloves, eye protection, and, when handling powdered lime, a dust mask. Never check the consistency with your fingers.

How much does limewash cost?

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The Cost of the Product

Ready-made limewash costs about $46 per quart and $125 to $140 per gallon in Canada, and a limewash primer costs $35 to $127 depending on the size. A gallon covers 250 to 350 square feet in two coats on a primed surface, or about $0.36 to $0.56 per square foot for the limewash alone. A very porous, raw surface absorbs more.

The Cost of Hiring a Painter

A professional painter in Canada typically charges $25 to $80 an hour, and residential painting generally costs $1 to $6 per square foot. Limewash is a specialty finish that takes longer to apply, so expect pricing at the upper end of those ranges. For larger projects, many painters charge a daily rate of about $350 to $600 for residential work.

When to Hire a Painter

Limewash is doable for patient DIYers on a small accent wall, but the result depends heavily on technique. An experienced painter knows how to dose the limewash, avoid lap marks, and get an even finish on large areas, such as a full living room, a stairwell, or an exterior brick façade. Ask to see photos of similar limewash projects, and make sure the quote specifies the preparation, primer, number of coats, and any protective topcoat.

An Artisanal Finish That Takes Technique

Limewash offers a matte, textured finish with depth and movement, a mineral composition, and excellent breathability. It needs good preparation, a primer on low-porosity surfaces, and a careful brush technique, and it costs about $0.36 to $0.56 per square foot for the product alone.

For a small accent wall, DIY is very realistic. For large areas, exterior brick, or historic masonry, a painter experienced with limewash will deliver a more consistent result.

Limewash FAQ

What is limewash made of?

Limewash is made from slaked lime (calcium hydroxide), water, and natural pigments. Some ready-made products add a binder to improve adhesion.

What is the difference between limewash and paint?

Limewash soaks into porous surfaces and stays breathable, while regular paint forms a film on top. Limewash also has a mottled, textured finish rather than a flat, uniform one.

Can you limewash over painted walls?

Yes, but only after applying a primer designed for limewash. Without it, limewash won't adhere to smooth, non-porous surfaces.

Is limewash safe?

Once cured, yes. It contains no harmful solvents, but it's caustic while wet, so wear gloves and eye protection when applying it.

How long does limewash last?

Indoors, limewash can last many years with gentle care. Outdoors, it weathers naturally and may need touch-ups in areas exposed to rain.