So you want to freshen up the look of your patio slabs? Maybe they are damaged and won’t clean up well, or perhaps you just fancy a change of colour. Either way, you have now begun to think about painting them, but can you do this? Can you use masonry paint on patio slabs?
Masonry Paint on Patio Slabs
There is only one way that I know to test this out, and that is to do some painting myself and see what happens. I will be painting some stone in place of a patio flag as I don’t have any patio flags lying around at the workshop, unfortunately.

Above is the paint I will be using for this little test. I will be using the Sandtex ultra-smooth white masonry paint, the big tub on the right.

So here is the stone we are going to paint, let’s see what happens.

Well, the paint goes onto the stone just fine, but we all probably expected that right? The real test will be what happens to it over time, and how will the masonry paint fare over winter. To test this I left the painted sample outside on the ground over a full winter.
In the photo below we can see the results of this test.

The masonry paint is at the right of this image. The left paint is actually just a regular emulsion, you can see the difference that the fungicide in the masonry paint has made to mould growth.
However it isn’t perfect and there is still quite a bit of greening to the paint, and remember this is after only about 6 months of being outside.
Can You Use Masonry Paint on Patio Slabs?
The masonry paint in my test went green quite quickly so would not be suitable for that reason alone, that is without including my next point.
Then there is the issue that masonry paint is not designed to be walked on. I would expect it would rub off and damage very easily with constant foot traffic.
Why Do People Use Masonry Paint?
One of the main uses for masonry paint is simply decorative. Probably the most common use is painting the exterior of homes to give them a fresh appearance, just like you would with walls inside your home.
There doesn’t have to be any special reason to paint the exterior of your house with masonry paint, although it does have lots of benefits, other than just waiting to change the look.
Killing Mould And Algae
One use of masonry paint that not everyone will be familiar with is that most masonry paints actually kill mould and algae and stop it from growing on the outside of the paint.
This is because they almost always contain a fungicide and herbicide to kill this growth.
Water Barrier
Masonry paints are nearly always waterproof, in fact, if the one that you are buying isn’t waterproof then I would consider swapping it out for one that is.
Waterproofing brick and stone can be a great way to prevent leaks from troublesome areas. Some stone and brick are actually not that watertight, counter to what you may think.
In areas where it is constantly battered by water, either due to being in an exposed location or having a faulty drain drip on it, it can start to penetrate and enter your home.
This can lead to damp patches on walls that just won’t seem to budge or in some circumstances full-on watermarks all over your walls.
Dirt Resistance
A lot of the more popular masonry paints also include some dirt resistance. What this means is that dirt is much less likely to stick to the paint as it is to the bare masonry.
This can mean the exterior of your home can look a lot fresher and cleaner for longer. This can be particularly important for people who live near busy roads where the dirt from passing traffic can soon have masonry looking dirty and tired.