The Best Patio Sealers
+ How to use them
By Daniel at DIY Gardening
Below you’ll find my recommended patio sealer products.
By using any of these sealers, you’ll:
- Protect the patio from scuffs.
- Prevent moss, algae and weeds from growing.
- Repel oil, fuel and grease.
- Achieve a wet or gloss finish if you choose such a product.
- Make cleaning much easier.
But first things first: Even the best sealer will fail if the surface isn’t cleaned correctly and allowed to dry thoroughly.
That means driveway and patio sealing should never be attempted in winter.
Daniel Woodley – Owner at DIY Gardening
This is The Fastest Acting Driveway and Patio Cleaner (Use This First)
If you want the patio sealer to do its job, you’ll need to thoroughly clean the surface first, so much so that it’s spotlessly clean.
While a pressure washer can do a good job, it doesn’t always remove the tough lichen and other organic matter that grows on the surface of some patios.
The best product for preparation is Sodium Hypochlorite.
Spray or rinse this onto the patio and leave it to dissolve algae, moss, lichen and other organic matter.
Once it’s had time to work, pressure wash the patio to finish off the cleaning, then allow it to dry – this can take several days in the summer and even longer in the winter, hence why we recommend patio sealing in the summer.
I also suggest testing this on a small patch first, just to double check it doesn’t damage the surface.
The Best Patio Sealer For Slabs
Everbuild 405 Path and Patio Sealer is one of the highest-rated sealers and has been used on hundreds of thousands of patios where it leaves a low-sheen finish with several other benefits:
- Acrylic-based so safer than solvent products.
- Roll on for ease of use.
- Slip-resistant finish.
- Contains a fungicide to prevent moss, algae and mould growth.
- Low odour and non-flammable.
- 5 litre and 25-litre tubs.
- Milky solution clears and dries to leave a protective, hard-wearing film.
- 1-litre covers 8 square metres.
- No need to dilute, it’s a ready to go product.
- 5 hour drying time at 20 degrees.
- Apply by roller or fine sprayer.
- Best results from 2 coats but a wet look can be achieved with 3 coats.
The Best Sealer For Concrete Blocks
While I’ve seen excellent results with Everbuild on various surfaces, I know from experience that SmartSeal’s Block Sealer is by far the best product for blocks.
Crucially, this sealer does a great job of soaking into the sand between the joints and hardening it so weeds can’t grow through and seeds can get caught into the joints.
SmartSeal is more expensive and is at the upper end of the price range, and you’ll need to use more of it, especially if you have lots of gaps between the block joints.
Here are the key points:
- Choose from matt or silk finish.
- 2 sq metres for the first coat and 3.5 sq metres for the second coat; even better coverage can be achieved on the third, optional coat.
- Apply by roller, brush or sprayer.
SmartSeal is my choice for block pavers, old and new.
Patio Sealer For Sandstone
If you want to seal porous natural stone, such as sandstone, Indian sandstone, limestone or yorkstone, you’ll need a specialist patio sealer. Regular sealers are designed for concrete and don’t perform as well on overly porous natural stone slabs.
The problem with natural, porous stone is how easily they turn green from mould, algae and other organic material that grows on the surface.
To prevent this, I recommend Resiblock, although be warned; this product is the most expensive you can buy at well over £100 for 5 litres.
For reference, 1 litre covers 4-6 sq metres but you only need one coat.
Also, for best results, it will need to be reapplied every few years at least, even sooner on high traffic areas.
How to Prepare The Patio For The SealerWhichever patio sealer you choose, preparation is key, and if you get this step wrong, you’ll ruin the appearance of your patio. If you’re treating a freshly laid patio or blocks, I recommend leaving them for at least a year so the salts within the material can draw to the surface where they can be removed. Some manufacturers claim that their sealers can prevent efflorescence, but in reality, they just delay it. (More about efflorescence here.) For older patios, I recommend the following steps:
- Brush off any leaves, dirt and pull out large weeds.
- Treat the surface with Sodium Hypochlorite (try a test patch first) and wait a couple of hours.
- Pressure wash the blocks to remove any organic material and dirt on the surface. A rotary washer is best, but a lance can also be used.
- Allow the surface to dry for at least 3 days and then brush in kiln dried sand. Professionals use a whacker plate to vibrate the blocks so the sand sinks into the joints, but DIYers can just use a brush back and forth.
- Brush off excess sand or use a leaf blower.
- Apply the sealer as per the manufacturer’s instructions.
Patio SlabsAs above but take extra care not to blow out the mortar in the joints. Also, if the mortar joint is cracked, consider repointing with a material similar to or the same as the original.
How Long to Wait After Rain or Pressure WashingApplying the patio sealer to a clean, dry surface is essential, but you shouldn’t forget that moisture well inside the slabs or block, or even underground, could rise to the surface and cause problems. I recommend waiting at least 3 days after pressure washing in the summer. I do not recommend any patio sealer in the winter as the ground is unlikely to dry out sufficiently, and the sealer won’t have enough time to dry before sunset.
Do You Really Need to Apply a Patio Sealer?While many patio sealer manufacturers will have you believe that these products are essential, they actually aren’t. The vast majority of consumers don’t use any type of sealant on their patios, and they do just fine. In fact, if the joints between the slabs or blocks are filled with mortar (for slabs) or sand (for blocks), then seeds can’t get into the gaps, and weeds won’t grow through. Patio sealers repel water and oil and can hold the sand in place; they can make cleaning the surface easier too, but they aren’t essential, and for surfaces that receive only very light foot traffic, they don’t achieve much at all. Silk patio sealers will alter the look of the patio but whether this improves or destroys the appearance is a matter of personal preference.
How Long Do Patio Sealers Last?While some manufacturers claim their products will last 5 years or so, most are rarely effective after 2 years. All of the products I’ve recommended in this article penetrate into the surface of the slabs or blocks but still, any wear and tear will render them ineffective on the surface. As a general rule of thumb, areas with lots of foot or car traffic will need to be re-sealed every 2-3 years while low-traffic areas should last 3-4 years.
Author: Daniel Woodley
Thanks for reading our guide to the best patio sealers. Daniel Woodley published this here at DIY Gardening and the article was last updated in December 2021.
Discover more helpful hints and tips from Daniel over at the blog.
Daniel is a keen amateur gardener trying to reduce his reliance on harmful weed killers and other chemicals but accepts there is a place for them in some scenarios.
He also enjoys growing vegetables and fruits, as well as his herbaceous border and container garden.
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