Slate typically comes from Brazil, Vermont, China and India. The Brazilian and Vermont slate varieties tend to have a low absorption rate, while Indian and Chinese have variable absorption rates. Softer slate requires more attention with sealing before and after installation compared to harder slate tiles.
Slate is a foliated metamorphic rock derived from shale and consisting mainly of grains of mica and quartz. Most slate is grey to black, but the rock may be red or purple, depending on its mineral content. The surface of slate is generally uneven with cleft planes which can spall or flake due to the cleaving of the stone along its layers.
A bit more knowledge about the origin of your slate will help you determine how you want to treat it. Brazilian slate is typically dense and has variegated colours while Vermont slate is typically dense, smooth and one consistent colour (black, blue, green red). In contrast, Chinese and Indian slates are typically variable in density (soft to hard) with variegated colouring. If you have a soft slate, typically Chinese or Indian, pre-seal using a deep penetrating porous stone sealer.
We provide specialised stripping & sealing solutions for slate floor surfaces.