Unsightly and stubborn, white spots on patio slabs are some of the trickiest blemishes to remove from outdoor paving, and if you don’t care for your natural stone paving properly, they’ll more than likely regrow rapidly.
Fortunately, even though white spots on patio slabs are fairly common, they’re also easily treatable with the right know-how.
So, if you want to know exactly how to remove white spots from paving slabs (and how to stop white spots on your patio from coming back), take a look at our guide below for all our top tips.
White spots are caused by lichens, and can thrive in dark, damp spots of your garden (image: freepik)
What causes white spots on paving slabs?
While it’s possible to get a variety of different coloured spots forming on your patio, white patio spots are certainly some of the more unique ones. Unlike black spots, white spots on your patio are more than just mould, they’re what’s known as lichens.
Within the natural world, lichens are not made of one organism but two – either a bacteria or algae, and a fungus. Together, these organisms work to create the sort of damp and humid environment where they can thrive, which in many unfortunate cases, is the microscopic holes and fractures found in the structure of your patio tiles.
What causes lichen white spots on patio slabs?
Although we’d like to say that there is one root cause of white spots on your patio, the unfortunate reality is that the growth of lichen white spots on patio slabs can be unavoidable when it comes to outdoor tiles and paving.
And this is to no fault of your patio slabs. Instead, it’s because tiny lichen particles are carried on the wind, which means that they’re quite likely to land on your patio or driveway after even a gentle breeze.
From here, the lichen spores will then burrow into your paving and put down roots to establish a firm anchor from which to grow and spread. Initially, this growth may be quite slow, but after a few years, white lichen will begin to rapidly spread, appearing as white splotches on your tiles.
However, in some cases, such rapid rates of growth can be enhanced if your patio or paving is located in a shaded area or is regularly exposed to the damp conditions brought about by moss and dirt, such as with driveways boarding a hedge or paths running down your lawn.
How to identify lichen white spots on patio slabs
As the name implies, lichen white spots on paving slabs can be readily identified by their whitish appearance. But they’re not always solely this colour. Many lichens may appear as a mix of orange and green or even greys and blacks, though they’ll likely still have whiter edges.
How to get rid of lichen on a patio
Now you know what causes those white spots on your paving slabs, it’s time to learn more about how to go about getting rid of them, and more importantly, how to do so without stripping your outdoor paving of its colour or staining it unintentionally.
Depending on the severity of the white lichen on your patio, you have two treatment options to choose from:
1. Diluted bleach
First things first, if the white lichen on your patio is fairly new or in small clumps, then you might be able to remove it with a simple home remedy of bleach and water; albeit one where the bleach is heavily diluted.
To do this, make sure your solution is measured at 1 part bleach to 10 parts water, i.e.; 100ml of bleach per 1 litre of water used. This will ensure that the bleach is not potent enough to damage your tiles but still packs enough of a punch to kill the lichen.
Once you have your mixture ready, you should then clean your patio in the following order:
1. Use a hose or a light pressure washer to clear away any loose debris and sizeable lichen chunks covering your slabs.
2. Next, treat the entirety of your patio or paving area (not just the lichen spots) with your bleach solution, using a scrubbing brush on the lichen areas to really work it in.
3. Leave your slabs for around ten minutes and then rinse the surface with fresh water to remove any excess bleach.
4. Wait for a day or two to see the effects and then repeat steps 1 to 3 as many times as needed.
In general, even if the first wash is highly effective, we’d always recommend doing two coats to make sure you get as much of the lichen as possible. And, of course, because you’re working with bleach, make sure you wear protective masks and goggles as well as clothes you don’t mind throwing out, to avoid any accidents.
2. Chemical treatments
If you’ve tried using bleach a few times and it’s failing to have any direct impact on the white lichen on your patio, or your lichen problem is pretty advanced, then your next port of call should be to look at using some form of chemical treatment to kill the lichen directly.
And the good news is that there are several excellent lichen chemical treatment options out there, though you should be careful to find one that has a low acidic level to avoid damaging your patio slabs.
To apply such a solution, simply follow the instructions laid out by your chosen product and then repeat said process until the lichen is gone, which may take several attempts if the lichen on your tiles is well ingrained.
How to stop white lichen from coming back
Having put in all the time and effort required to eliminate the white lichen from your patio, to begin with, you probably want to stop it from coming back again in the future to avoid repeating the cleaning process.
Therefore, you’ll want to treat your patio on a yearly basis with an anti-lichen wash to eliminate new spores or growth patches before they can get a hold, ideally on a warm weather day.
Better yet, having given your tiles a thorough cleaning and treating them for mould and lichen, seal your patio slabs with one of the excellent sealing products in our fixing range. This will prevent any spores or moisture from getting into your tiles, preventing lichen growth.
Bring your new patio to life with Stone Superstore
And there you have it, now you know how to get rid of lichen on your patio without damaging your tiles.
For those longing to give their garden space more of a complete refresh, it might be time for a renovation project with help from the Stone Superstore team! From fantastic traditional natural stone paving solutions to sleek and stylish outdoor porcelain tiling options, we’ve a variety of indoor tiles and outdoor paving options in our full tiling range.
Start browsing today and be sure to order your free samples to kickstart your next project. You can also head over to our inspiration and advice blog for even more helpful articles on patio maintenance, such as our piece looking at how to care for porcelain paving.
