Limewash paint is an affordable way to liven up a dull and lifeless brick house, and it’s an easy DIY almost anyone can tackle!
For something that’s been around at least since the time of Egyptian Pharaohs, limewash is often misunderstood and occasionally maligned. And as we all know, misunderstanding leads to misinformation under the guise of knowledge and instruction.
We’ve been amused and baffled reading blog posts on limewash and watching videos on social media. Some folks contradict themselves within the same article!
So, if you’ll indulge me, I’m going to set the record straight. Let’s have a look at what limewash is, how it’s used and why you should consider it for your brick house.
Is Limewash Paint really a paint?
First, let’s settle this burning question once and for all.
Yes, Limewash is most definitely a paint! Oxford Languages defines paint as “a colored substance which is spread over a surface and dries to leave a thin decorative or protective coating.”
Limewash paint fits that definition to the letter, and don’t let anyone tell you otherwise!
Limewash is different than modern latex, acrylic or other paints most of us are familiar with. Modern paints cure into a non-permeable film. Limewash paint, in contrast, calcifies onto and into the brick (or other porous cementitious material) in a permeable manner that allows air and water to pass back and forth.
Okay great, Poindexter, but who cares?
Benefits of Limewash Paint vs “Regular” Paint for Brick Houses
Before I answer this, I’d like to mention that limewash paint has benefits far beyond brick and masonry, both inside the house and out. But lest I get too broad in scope, I’m just going to focus on brick houses.
Brick, as a construction material or a non-structural cladding, breathes. It draws water in when it rains and then allows that water to evaporate out. This is the natural way of brick, and it needs to take place for the brick to retain its integrity.
Modern paint suffocates the brick, as the latex (or other) film forms a barrier that interrupts its natural breathing cycle.
If this sounds a bit murderous to you, well, it is!
By suffocating the brick, you quicken its demise. Trapped moisture weakens the brick over time, and the freeze/thaw cycle hastens deterioration in cold climates.
Limewash paint, as noted above, allows air and water to flow in and out of the brick unimpeded, just as nature intended. As a bonus, the calcified coating of lime further acts to preserve the brick and extend its useful life.
On top of that, lime is naturally alkaline, with a pH around 12. This alkalinity makes it an inhospitable environment for bugs and other pests.
So What is Limewash?
Limewash has been used for millennia – largely unchanged for most of that time because at its core, it requires only two ingredients: hydrated (slaked) lime and water.
Great. Slaked lime. Got it!
Okay, let’s dig a little deeper, because science is cool and knowledge rules!
How is Limewash made?
It all starts with limestone. Despite the marketing efforts of certain brands, limestone is nothing exotic, and the limestone from this mountain range [points finger in this direction] is no better than the limestone from that mounting range [points finger in that direction]. Limestone is primarily calcium carbonate (CaCO3) – the very same ingredient we use for our beloved DIY Chalk Paint Recipe.
Calcium carbonate, while helpful in making chalk paint and about a thousand other things, is not enough to make limewash paint.
First, the calcium carbonate needs to undergo a calcination reaction, or put simply, you gotta cook the crap outta the rock at about 1300 degrees Fahrenheit until it decomposes into calcium oxide (CaO) and carbon dioxide (CO2). This resulting calcium oxide, known as quicklime, is a highly caustic and alkaline substance.
Back in the crummy old days of unhinged tyrants, mass graves and gangsters who loved nothing more than to “moider da rat bastid,” quicklime was often sprinkled over the recently deceased to speed decomposition and help the bad guys get away with their crimes. What those goons and despots got wrong was that quicklime is actually a preservative – it didn’t help decomposition one bit! But it did help control the odor, so after they filled in the graves, they wrongly assumed they’d destroyed the evidence of their wrongdoing.
Okay, we’re almost there, so stay with me!
To get a step closer to limewash paint, water is added to the quicklime in a process called slaking. This is a massively exothermic process, meaning it gives off heat. With the right amount of water, quicklime will almost instantly reach 300 degrees Fahrenheit. But with a little more water added, a more optimal lower temperature results – perfect for slaking. The result of the slaking process is the conversion of the CaO (calcium oxide) into Ca(OH)2 (calcium hydroxide).
The calcium hydroxide remains stored in water for up to two years. This aging period improves its binding properties, and this is what plain old calcium carbonate lacks.
I’ve read some articles by other DIYers claiming this brand or that brand “ages the slaked lime to perfection” like it’s some sort of fine wine or cheese. This is a bunch of hooey. All commercially available limewashes contain aged slaked lime!
Did you know?
There is a way to make limewash on-the-spot with unaged slaked lime, but it is well beyond the scope of this article and a far more involved process for the DIYer. It’s called “hot limewash,” and it’s making a comeback in certain restorative construction circles. The quality is said to be far superior to aged-slake limewash.
Now the calcium hydroxide – called slaked lime, hydrated lime and a few other names – can be mixed with water to form limewash paint!
Of course, you don’t have to go through all that gobbledygook! You can buy hydrated lime at the hardware store and mix it with water yourself! I’ll address that and other pre-mixed brands a little later in the post. For now, let’s carry on and talk about the versatility of a limewash paint finish.
Types of limewash paint finishes on brick
Limewash paint can yield a slight translucent whitewash look all the way up to completely opaque coverage. Most people tend to favor a distressed look achieved by applying one coat of limewash paint and then selectively removing areas of limewash with a garden hose. By doing so, they’re trying to replicate how a single coat of limewash would naturally distress over time, but to my eye, when done indiscriminately, it can look just as awful as those overly-distressed “shabby chic” pieces of furniture that polluted everyone’s social media feeds last decade. You remember – the ones that looked like they got caught in the middle of a three-way gorilla fight.
With two or more coats (like we did), you get an opaque finish that won’t readily weather. In fact, according to the Technical Data Sheet of the brand we used, a two-coat application will be good for “20-30+ years.” But you know how it goes – they promise the moon and deliver a hunk of blue cheese – so we’ll see how this stuff holds up over time!
How to DIY limewash a brick house
You, sir or madam, are a rock star and a scholar for making it through my chemistry lesson. Now let’s get painting!
Tools and Supplies for Limewashing a Brick House
Brick House limewash painting SUPPLIES LIST
Affiliate links are provided below. Full disclosure here.
First, let’s see a before pic. Actually, I’ll show you two. Here’s the beforiest of them all – from the month we moved in.
And a year later after we started to improve the landscaping.
Limewash paint works best on clean brick with open pores, so that means power washing. To reach the highest peaks, I used a telescoping extension wand, and I hit every square inch not only to clean the brick and mortar, but to remove the sandy patina that most bricks had. It was like a sand-colored German Smear, but the power washer blasted it right off. I probably could have left it, but I didn’t want to risk the sand flaking off and carrying calcified lime with it.
Power washing was a slow and tedious process – especially with the wand fully extended. But it needed to be done, so there were no shortcuts.
The joke of a gutter system created areas of algae – very satisfying to wash!
Sandy smear on the left, cleaned wall on the right.
Making the Limewash Paint
There are two ways to make the paint for your brick house – make it yourself from hydrated lime and water or make it from lime putty available from several companies.
The former is by far the cheapest method, but you’re stuck with one color – pure white. The latter is more expensive, but you have the option to tint the limewash to your desired shade. I’ve studied the Material Safety Data Sheets for several brands, and unlike the hydrated lime + water limewash, the lime putty brands are made from 10-40% hydrated lime with calcium carbonate and chemical binders making up the rest.
The buckets of lime putty need to be diluted before use, but before that, they require mixing, as the slaked lime putty and water readily separate.
I used a large mixing paddle with my drill to mix the putty and water back to a uniform consistency. It resembles sour cream when properly mixed.
Here is the mixed lime putty.
The desired finish – whitewash, distressed, or opaque – dictates the level of dilution.
For full coverage opaque, we found that a dilution of 50% worked best. That means 1 part water to 2 parts concentrate. And yes, I wrote that correctly. Dilution is different than mix ratio. A 50% mix ratio would be 1:1. A 50% dilution is 1:2.
I mixed the limewash paint in a separate 5-gallon bucket with a smaller paint-mixing attachment on my drill.
Limewashing the House
A test patch helps to understand how the limewash paint goes on the brick, how it dries, and how it distresses.
This is one coat, still wet. Limewash paint goes on translucent and becomes opaque as it dries.
Before I applied the limewash, I first sprayed the section of brick with a garden hose. This is a crucial step, as damp brick allows the limewash paint to dry more slowly which increases absorption of lime into the brick.
The limewash paint gave me no surprises, so I started in on the main front face of the house – nothing like living on the edge!
I used a large, soft-bristle masonry brush to apply the limewash paint. The dense, soft bristles hold a huge amount of the watery paint. With my babes’ help, we knocked out 1 coat on the huge garage face on the first day. We could have possibly finished two coats, but we had two rain delays.
Finishing up the wall before sunset after the second rain delay with Baris’s help.
My preferred method to apply the limewash is to load up the brush and then focus on the mortar lines. The deep mortar requires a heavy coat of paint, and by focusing on those lines, the brick faces got ample coverage in the process.
The second day, we again focused on the garage wall, and again we had rain delays, so we only finished the second coat.
Can You Spray Limewash Paint?
On the third day, I wanted to try a paint sprayer to see if it would speed things up a bit.
But the sprayer couldn’t get enough limewash paint into the mortar lines without overspraying the brick faces. I quickly gave up on the idea and had to go back over the mortar with a brush in the sprayed area.
For the rest of the house, I used the masonry brush. With a little practice, I nailed down my technique and hummed right along!
If we wanted a distressed look, l would have sprayed the bricks here and there after the first coat. But for the full coverage opaque look, the Technical Data Sheet recommends two coats. The first coat needs about 3 hours to dry before second coat application.
Limewashing is a messy business, make no mistake. But most spills and drips clean easily with a hose or a damp cloth if caught early. If not, a wire brush helps to remove it from sidewalks, driveways and shingles.
Some Additional Work
With all the work we put into the house, we couldn’t just leave the crappy landscaping as-is, so we removed all the old shrubbery (before limewashing), and prepared the beds with landscape fabric.
Handan bought a huge swath of jungle from various garden centers, and she and The Boy inserted those plants into the ground.
Meanwhile, I hauled wheelbarrow loads of river rock from the 7 tons we had delivered.
I spread the rock around the beds. To keep the plants cool, we later moved the rock away from the stems and trunks and placed a nest of pine straw around each.
We hung a new pendant in the portico. Well, to be fair, I dropped and smashed it while trying to hang it. After I got the glass replaced by a local glass shop, my babes insisted on hanging it herself…and she nailed it!
During this whole process, we hired some pros to tear out the crappy DIY gutter system the previous owner had installed and replace it with a proper 6-inch system complete with rain chains for the front portico.
Our Limewashed Brick House
Okay, enough yapping, let’s see the finished product! But first let’s have another look at the before pic.
And the after…
If you’re wondering why the trees look painted, it’s because they are…with limewash paint.
Limewashing trees is a centuries-old practice known in just about every country in the world. It protects against sunburn, sun scald, frost, disease and many wood-boring pests. These crape myrtles shed their bark like crazy, as they take the full brunt of the afternoon sun. Since limewashing the trunks of three crape myrtles, the peeling has slowed, and the blooms have increased threefold!
Where to Buy Limewash Paint
Here are four options for limewash paint suitable for a brick house.