How To Clean Indian Sandstone Paving Slabs

Discoloration and a loss of the sheen and texture of Indian sandstone paving slabs are a problem regardless of where you live in Britain. Time, traffic, the type of plants that surround the paving slabs, and the proximity of the slabs to water all have an impact on how fast the paving slabs become dirty and how frequently the paving slabs need to be cleaned.

One of the primary considerations in cleaning Indian sandstone paving slabs is the type of grout or material that was used to level the slabs and to fill the joints. Sand is typically used that has a similar color to the stones used. A sealer that prevents the sand from discoloring is a benefit that prevents loss of sand during cleaning and due to normal wear.

The materials that you need to clean Indian sandstone paving slabs depend on the material that causes the discoloration and how porous the sandstone is. Very porous stone needs careful attention to prevent the removal of the stone when it is cleaned.

What causes the stains?

Knowing what has caused the discoloration of your paving stones is a great help in determining what cleaner to use and what cleaning method to use. The most common contaminates are dirt, algae, lichens, and moss.

Dirt gets tramped into the stone surface. There is a chemical adherence of dirt due to its negative charge as well as a physical impression of dirt into the surface of the sandstone slabs.

The green discoloration of sandstone is usually caused by algae. Alga is in the air. The spores are microscopic but they can travel miles on the wind. The spores of algae become residents of your sandstone when it is wet and rapidly grows into large colonies.

Black, grey, and white spots on sandstone slabs that get larger over time are caused by lichens. Lichens are a symbiotic relationship between algae and a fungus. The tiny organisms can be transported by the wind from trees that are close to your paving slabs.

Moss from any local river or stream can be transported by air to your lovely Indian sandstone paving slabs and produce an unsightly green border around each slab. The moss grows in the dirt between the paving slabs.

What to avoid using

Cleaning Indian sandstone paving slabs is a matter of what to avoid and prevent a change in color or a complete loss of color. Any cleaner that contains iron will react with Indian sandstone and can produce a rust color on the paving slabs. Many fungicides that remove lichens can discolor the sandstone permanently.

The simple approach

Dirt, moss, and algae can usually be removed using a dilute mixture of household bleach. The bleach should not be used straight out of the bottle. Dilute the bleach in the same amount of water as bleach. Pour the bleach mixture on the slabs and wait for 30 minutes. Wash the bleach and contaminates away with plenty of water.

The sodium hypochlorite in the bleach kills the moss and algae but it will not prevent a new infestation.

The lichen problem

Bleach will not destroy the majority species of lichens. The lichens can be removed by physical brushing with a wire brush. This method has the dangers of marring the appearance of the sandstone. Fungicides made for sandstone will remove lichens. Do not use fungicides that contain iron because the iron will make some of the minerals in sandstone turn brown and rusty colored.

Power washer

A power washer is a great tool for cleaning Indian sandstone paving slabs. The machines are especially useful if you have a large area of sandstone to clean.

Care must be taken in the amount of pressure used on sandstone. Some sandstone is relatively soft and needs low pressure cleaning that may require more than one pass.

Power washers can combine chemical cleaners. Care should be taken that no iron is in the cleaner and that the concentration of bleach is about one half of the concentration of household bleach. It is cheaper to use household bleach than to buy sodium hypochlorite cleaners.

When you need help and advice with cleaning Indian sandstone paving slabs contact the experts at Stone Traders