Despite the fact that slate floors are well-known for their beauty and long-lasting durability, the sealers and waxes that are applied to them over time can darken their appearance or cause dirty-looking spots. If the sealer is waxed over, dirt will become trapped in the sealer. It is possible that some areas of the floor will appear worn, or that a powdery substance will develop on the surface. Topical sealers, on the other hand, have a tendency to scuff and dull over time. When any of these things happen, it becomes necessary to remove the build-up and sealer from the tiles in order to restore the natural beauty of the tiles. This is a difficult task, but the results can be rewarding if you put in the necessary effort and patience.
First, we remove everything from the floor in order to start over from the beginning with a fresh slate. No pun intended. During the first stage of the slate stripping procedure, we completely remove all of the old sealer from the slate surface. Some slate tiles might only have a transparent impregnating sealer which is fairly easy to remove, but on some occasions our customers may have applied multiple coats of topical varnish over the years. Over the long period these coatings build up to such a thick layer that it could take several days for us to remove. This is particularly challenging along the edges of the room where the tiles meet a delicate skirting board, or between the tiles where the varnish has formed pools in the grout lines.
Once the tiles are thoroughly deep cleaned, the second step is to thoroughly neutralise the floor with a neutral pH cleaning solution. The third stage requires drying time. After the cleaning process we may need to wait a day or two to allow the stone to dry completely before applying a sealant.
Stage four is the final stage and requires sealing of slate tiles. Some sealants can be applied to stone which contains a 10% moisture content, in which case the slate floor can be sealed on the same day as the cleaning service. These sealers are semi-permeable, in that it allows moisture gases to evapourate by permeating the membrane.
On the other hand, if a topical coating is applied to the slate it’s important that the stone contain at most 5% moisture, anything higher than this would create a form of efflorescence. This is when a solution of water and dissolved salts tries to evapourate but becomes trapped on the surface.
Here’s an example of a slate floor that we restored in Buckinghamshire. The contrast of colours between the tile, as it was when it was first bought, compared to the floor underneath, which has 15 years of varnish applications. This “little” 100sqm project took a full week. We managed to remove all the sealer so that it looked new again.
Do you need to have your slates professionally cleaned?
Slate restoration is a time-consuming and labour-intensive process that requires patience. A stone restoration contractor with extensive experience and knowledge in the field should be hired in order to restore your slate to its original condition. For more information on slate restoration, please refer to our Slate Services section of our website.