When it comes to building design, sandstone walls and pavers are a firm favourite of mine! Their natural appearance and golden, rich colour creates a timeless appeal that will make your neighbours jealous. The only downside is that they’re easy to stain and require utmost care when cleaning.
Like timber and other natural products, sandstone will gradually oxidise and lose its rich colour. Its colouring will reduce over time when dirt is blown on the surface, or deposited from footsteps. Excessive exposure to moisture can also lead to the formation of a green tinge, caused by algae and mould.
Staining can be caused unknowingly through a number of common occurrences such as:
- Spillage of acidic foods, soft drinks and wine (not just red wine).
- Harsh chemicals or cleaning products containing bleach or ammonia.
- Cleaning with vinegar – for some reason there are people who clean everything with vinegar. Vinegar is far too acidic for sandstone, save it for your fish and chips!
- Puddles of water being left to sit. To fix this you may need to re-lay an uneven paved surface or investigate a drainage issue.
- Rust which has been transferred from adjacent metal objects, such as outdoor furniture, fencing or signs.
Sandstone is more prone to staining and discolouration due to its high porosity levels. Stains don’t just sit on top of the surface, they are absorbed deep into the stone. This means that utmost care must be taken when cleaning and restoring sandstone surfaces.
Sanding and chiseling are unlikely to reach the depth required to remove stains. All you’ll achieve is making an unsightly hole in your sandstone and exposing it to moisture, leading to crumbling and greater structural issues. Even excessive force from high pressure cleaners can cause this level of damage, so be careful!
The most gentle and effective way of restoring sandstone is to identify the specific stain you wish to remove and select the right cleaning formulation to break down it’s molecular structure, release the bond and draw it to the surface. At this point the stain can be carefully removed by using a pressure cleaner at a lower pressure setting with a wide angle jet, or if the surface is old and fragile, simply remove it by hand. This method applies to heritage listed buildings, as well as modern structures.
Sandstone surfaces can be protected from stains and discolouration with the installation of a non-sacrificial invisible coating.
Craig Cavanagh, our stain removal specialist in South-West Sydney, installed the a protective coating on the wall of a beautiful waterfront apartment complex in Narrabeen (see images below).
This coating type will maintain the sandstones rich of colour and reduce cleaning costs by up to 50%, and cleaning time by up to 45%, during its lifespan. The invisible appearance ensures that the protective coating does not detract from the sandstone’s natural beauty, and makes the coating ideal for those wishing to protect their heritage listed property in a compliant way.
The Stain Eaters provide sandstone cleaning, restoration and coating services throughout Victoria, New South Wales, Queensland and South Australia.