Sealing Limestone Pavers in Lesmurdie With Silane/Siloxane

silane/siloxane sealer beading on limestone pavers

This is certainly not going to be a visually exciting post.

A client came to us, having hired a pressure cleaner to clean and seal 250sqm of limestone pavers at their property in Lesmurdie. The previous contractor had done a reasonable pressure cleaning job, but the sealer had been applied incorrectly and had become flakey and then washed off with the first rain. Hard to say for certain as we could not get any information from them, but most likely a penetrating sealer that had reacted with a cleaning agent such as Sodium Hypochlorite. Fortunately, it was not a coating sealer, so we didn’t need to do any chemical stripping, but we did wash it with a solvent cleaner, to make sure there was no residue left.

Being that it was a recently cleaned surface, we never thought to take before photos.

“limestone pavers” are not actually limestone. They are a moulded concrete paver with some crushed up limestone added into the mix for colouring. They’re mildly alkaline due to the Calcium Carbonate which makes them prone to growth. To make matters worse, once the top side of the paver which was at the bottom of the mould during manufacturing wears even only a little bit, the smooth surface disappears and makes them highly porous and even more susceptible to growth such as black spot.

We could stay in business just by cleaning these types of pavers which are so problematic. I would go far to say that if there was only one type of surface that required sealing, it would be these.

After re-cleaning these pavers and ensuring there was no chemical residue, we returned a few days later, cleaned the surface of contaminants using a blower and then applied the sealer. Being a large area of 250sqm and the owners already having had a poor experience with a sealer, they opted for a Silane/Siloxane water based penetrating sealer, rather than a much more cost prohibitive Fluoropolymer sealer. This will keep their pavers looking good for several years, and they can decide then if they’d like another Silane/Siloxane application or try something a bit more robust.