Efflorescence on Pavers: Why the White Haze Appears and How to Remove It

Have you noticed a white, chalky haze creeping across your pavers? That isn’t a stain or a cleaning mishap. It’s efflorescence, a natural process that affects concrete, stone and masonry all over Melbourne. While it can look alarming the first time you spot it, efflorescence is common and well understood and in most cases easy to treat.

In this guide we’ll explain why the white haze happens and if it is something you really need to worry about. We’ll show you how to remove efflorescence for good and make sure it doesn’t come back. The Paver Shop can help you get your pavers looking their best again.

If you’re looking for a more general upkeep guide, you can read our cleaning and sealing pavers article.

What Is Efflorescence and Why Does It Happen?

Efflorescence is a white powdery covering of your pavers, or a crusty stain that appears on the surface of your brick, concrete or stone pavers.

It is a natural byproduct of the cement curing process and happens when water gets inside the pavers. There, it dissolves natural salts in the stone, and carries this to the surface as it evaporates. Much like salt lakes, when the water evaporates it leaves the tiny granules of salt behind that it picked up.

Is Efflorescence Harmful to Your Pavers?

No, efflorescence is not harmful to your pavers. It is purely a cosmetic effect caused by the natural salts in concrete rising to the surface as water evaporates. Being cosmetic, however, can mean your garden path or driveway can look faded or dirty.

The salt, before it is dissolved or removed, does not add any structural strength to the pavers. Therefore, the removal of this salt will not weaken your pavers, or the wider picture of the paving around your pool or backyard.

Why Melbourne's Climate Makes Efflorescence More Common

Melbourne’s changeable weather, humid conditions and wet days, create the perfect environment for efflorescence. It is a simple cycle of becoming wet and then evaporating, that makes the white crystals appear.

High Humidity

High humidity means slower evaporation. The water that is trapped inside your pavers or beneath it, takes longer to evaporate, so it penetrates deeper before leaving. This also means it can dissolve more minerals on the way back out.

Frequent Rain

Melbourne has a lot of rain during winter and early spring, with September and October being the wettest months of the year. When the ground is waterlogged from so much rain, the groundwater rises. It pushes more minerals up through the pores of your pavers, bringing more soluble salts with it.

Temperature Variations

The ability of Melbourne weather to change at the drop of a hat can cause efflorescence. Sudden bursts of sunshine and hot winds can rapidly evaporate moisture on the surface and just below the surface of your pavers. This draws up more moisture from beneath, called a capillary action, and that draws more minerals to the surface as well.

How to Remove Efflorescence from Your Pavers

The good news is that, while efflorescence on your pavers may seem unsightly, it will not permanently damage your pavers, and it is actually quite easy to clean with an acid-based efflorescence cleaning solution.

The 5 Steps to Cleaning Efflorescence:

1. Pre-soak: Use a simple garden hose to pre-soak your pavers. This acts as a soft barrier to the cleaning acid, so it won’t soak into the pavers too quickly. This could damage the stone.
   
2. Apply the cleaner: Spray, or pour a commercial cleaner, onto the pavers. There will be directions for mixing on the label, so follow them precisely. Let the cleaner sit on the pavers for 10 to 12 minutes.
   
3. Scrub: With a stiff-bristled broom, scrub the pavers. Don’t allow the acid cleaner to dry on the surface. If it is a sunny day and it is drying out before ten minutes, get in and scrub with the broom.
   
4. Rinse: Back with the garden hose, rinse the pavers thoroughly. You don’t want any of the acid cleaner left behind, as it will slowly eat away at the pavers. Also, any soap or foam left will be full of the offending salts, and will settle back onto the pavers if left to dry.
   
5. Neutralise: If you’re using a heavy acid mix, or a home-remedy, such as 1 part vinegar and 2 parts water, make sure you then wash the area with a mix of baking soda and water, to further negate any acidic reaction.

How to Stop Efflorescence Coming Back

Now that you’ve washed away the unsightly efflorescence on your pavers, it's time to make it so it never comes back. Now while you can’t change or remove the natural minerals in your pavers or the earth upon which they’re laid, you can block moisture getting into the pavers in the first place. There are two main ways you can do this.

Seal the Pavers

Once your pavers are completely dry and clean, you can apply a breathable penetrating sealer. This creates a barrier that stops moisture getting into your pavers, but still lets moisture evaporate out. Don’t use a sealer that completely traps moisture, as this will trap any that is still inside your pavers from getting out. This will encourage the growth of mould and mildew and can stain your pavers

Improve Drainage

Direct any downpipes from your roof away from your pavers. If you have sprinkler systems near them, try and adjust it so they don’t wet your pavers when they’re on. Also try to have your pavers on a slight slope so rainwater can easily drain off them.

Need help tackling efflorescence on your pavers?

The Paver Shop supplies sealers and chemical cleaners built to stop the white haze coming back, along with our full range of natural stone and concrete pavers if you're ready for an upgrade instead. We service Thomastown, Bundoora, Preston, Greenvale, Pascoe Vale and Thornbury, with free quotes for supply and installation. Visit our Thomastown showroom or get in touch to talk through your options.

Get Efflorescence Sorted with The Paver Shop

Efflorescence might look unsightly, but as we've covered, it's a harmless and totally manageable part of owning pavers in Melbourne. With the right cleaning approach and a good sealer, you can get rid of that white haze for good and keep your outdoor space looking sharp all year round.

If you're dealing with stubborn efflorescence or you're simply after some expert advice, the team at The Paver Shop is here to help. From sealers and cleaning products to a full range of pavers if you're considering a refresh, we've got everything you need. Get in touch or drop by our Thomastown showroom for a chat.