There’s nothing worse than a tired looking old patio, all faded and discolored with green growth or black spots of lichen. It actively discourages you from using it.
Natural stone patio slabs do fade in the sunlight, and poor drainage with constant shade can promote the growth of green algae and black lichen. You can paint or seal faded patio slabs to return them to their former glory, or carefully clean them with natural products if they become discolored.
In this article we’ll consider why patio slabs fade and discolor in more detail, and look at how you can paint, treat or wash your patio stone to make it look as good as new.
What Makes Patio Slabs Fade & Discolor? (Why Is My Patio Turning Green?)
Time, footfall, sunlight, rain… Paving slabs have a tough life, and over time, this shows on their surfaces. Rich colors can fade, and paler slabs can discolor or turn an unattractive greenish shade.
With natural stone pavers, fading happens naturally in sunlight. Other than installing stone paving slabs in shady areas only (and this causes its own issues…), there’s not much we can do about this.
You can apply a sealant to stone slabs, which will give some protection against sunlight. If you’re looking for a fade-resistant paver, try porcelain tiles for your patio.
If the sun causes fading, surely siting patio slabs in a shady part of the yard will help? Unfortunately, that’s not the case. Sure, your slabs won’t fade, but they might slowly turn that unpleasant shade of green we mentioned earlier.
Green deposits (algae and mold) develop in areas that are moist and shaded. They can grow on pretty much any surface, and are worse during fall and winter when there’s less sunlight and warmth.
There’s very little that can be done to completely eliminate algae and mold, even in dry climates, as it will seek out any shade or latch onto the moisture that comes from simple activities like watering plants.
Having a well-drained patio will help, as water cannot collect. In the end, however, a good spring clean and plenty of scrubbing is the best way to prevent the green from taking over.
How Do You Make Old Paving Slabs Look New? (Cleaning Tips)
Often, a good scrub can make old paving slabs look new. With a bit of effort and the right cleaner, old paving slabs can clean up really well.
If you want to use cleaning chemicals, make sure you know what your slabs are made from, as different materials need different cleaners. For example, limestone is damaged by acid so you must use a pH neutral cleaner. Slate is tougher and you can use bleach; but even though granite seems robust, it won’t take either acid or bleach.
Our rule of thumb? Always read the label. Make sure the product is suitable for your slabs, and look out for formulations that won’t harm any neighboring plants or lawn. At Take A Yard, we’re big fans of vinegar as a more natural cleaning material (although watch that acid content for calcium stone slabs).
The good news is that regular cleaning will keep your old patio slabs looking fresher for longer. For regular housekeeping, first brush your patio with a stiff yard brush, making sure you get into all the gaps.
Brush the debris right away from the pavers, or it’ll go mushy when you wash it. Then, the low-maintenance way to wash your pavers is to use a bucket of soapy water and a scrubbing brush. You can use a pressure washer, but keep it at a low setting: an aggressive blast can damage the surface of the slabs.
After cleaning, you may like to apply a sealant to your slabs. Again, this depends on the type of stone, as some take better to being sealed than others. The advantage of sealant is that it’s easier to clean in future and should guard against staining.
How To Lighten & Stain Old Patio Slabs
How do you lighten dark and dirty looking patio paving slabs? You could use a bleach and water solution. This will certainly lighten your old patio slabs – but, it could also damage them, along with any plants it accidentally touches, your garden furniture, and even your clothing.
We think it’s not worth the risk. Our gentler vinegar solution can help (again, watching that acid content for calcium-based stone).
Happily, in many cases, the dark color is simply a layer of dirt and a good clean will lighten the slabs by a few shades. If the dirt seems embedded, this is where a pressure or jet washer does a great job, lifting several layers of dirt in one go. As we mentioned earlier, take care not to blast away the whole surface of the pavers by using a lower spray setting.
If you have concrete patio slabs, you can give them a new lease of life by staining them. You can buy a concrete stain in a DIY store or online. Remember it’s not paint, and the result will be more of a refresh than a drastic change.
Still, it’s a great way to rejuvenate your patio and bring old concrete slabs back to life. Make the job easier by using a paint sprayer: it’s quicker and gives you a more even finish.
Is There Paint For Paving Slabs?
Want a more dramatic new look? How about painting your paving slabs? You can get special exterior paint for pavements and tiles. Look out for useful features like primer-free paints, non-slip formulations, and scuff-resistant finishes. Eco-friendly paints are the best for use in your yard.
Some paints are tougher than others. Work out how heavy the footfall is on your patio (is it on the main route to the house doors, or tucked away in a quiet corner of your yard?) as that will depend on how robust you need the finish to be. It’s also worth reading the online product reviews.
Before you start, the patio needs a good sweep and possibly an algae or mold treatment. If there are grease stains from barbecue spillages, you may need to clean these with a degreaser, as they may show through the color and spoil the seamless look.
Then, test the paint on a small section of the patio, just to make sure it’s the right shade for you. Preparation done, it’s time to start painting. It’s super-easy to paint a floor: simply use a brush, paint roller or paint sprayer, depending on how large the area is.
You can protect as well as color your slabs with a tinting sealant. This forms a protective layer over your slabs, then you can gradually deepen the color with extra coats. Check that the formulation is suitable for your surface: some will color both concrete and stone, others are more specialist.
Once dry (and this can take a good few hours, so watch out for scampering paws), your patio will have a fabulous new look. Great excuse to upgrade your outdoor cushions and plant pots to coordinate with the new color…?
Is it Possible To Remove Black Lichen Spots From Pavers?
Have you started to notice black spots on your patio slabs? It’s not unusual. These annoying black dots are spots of black lichen. Tiny, tiny spores are blown by the wind from leaves and trees onto your patio, where, especially if it’s warm and wet, they will settle and grow.
Not only do they expand, but they feed on the minerals in natural stone, and burrow below the slab’s surface. It can take a couple of years for the lichen to develop from dust-like spore into ugly black stain.
Well, that was cheerful: our patios are invaded by unsightly and burrowing lichen spores. Thankfully, they can be treated and your patio slabs restored. You can buy safe and biodegradable black lichen remover spray, which kills the lichen but doesn’t harm pets or plants.
You’ll find the treatment online or in garden stores. It’s not a difficult job, but you will need to move all furniture and pot plants, thoroughly clean the patio, and wear protective equipment while you’re carrying out the job.
If you prefer a natural approach, try scrubbing the lichen with a white vinegar solution. You’ll need to scrape away at the top layer of lichen first, before washing with vinegar and water.
Give it two days, then brush away the dead lichen. It should kill the lichen, but may leave some staining behind, which is where a commercial lichen remover has the edge.
To avoid a faded or discolored patio, you can always protect your stone slabs with paint or sealant to shield them from the sun’s harmful rays and prolong their life.
Alternatively, if your stone patio is afflicted with unsightly black spots of lichen or green mold – then you can always just wash it down using environmentally friendly cleaning agents, or try carefully pressure washing your patio to restore it to its former glory.
Whatever course of action you take, you’ll be happy you made the effort when you’re able to entertain friends and family again on your ‘good as new’ stone patio.
Homeowner and property investor Larry Jones founded Take a Yard in 2020 to bring you the very best outdoor living content, based on his years of experience managing outside spaces. Read more >