How to seal natural stone
Slate, sandstone and travertine all benefit from sealing. Here’s which sealer to use, how much you need and how to apply it properly.
Natural stone is porous. Left unsealed, slate, sandstone and travertine soak up water, oil and wine, and stains can settle below the surface where no cleaner reaches. A sealer fills those pores so spills sit on top and wipe away.
Sealing is the last step of any stone installation and the cheapest insurance you can buy for a new floor or wall. It takes an afternoon, and it is well within reach of a careful DIYer.
Which sealer should you use?
We stock two sealers for natural stone, each in 5 L and 20 L containers. Superseal is the workhorse for floors and paving; Water Block is an invisible sealer that suits wall cladding and any stone you don’t want to look treated.
| Superseal | Water Block | |
|---|---|---|
| Type | Durable, water-based general-purpose sealer | Silicone, water-based, invisible quick-drying sealer |
| Made for | Slate, sandstone, brick and paving | All natural stone — slate, sandstone, travertine, marble |
| Best applied with | A roller or paint brush | A spray bottle or spray pump |
| Coverage | ≈5 m²/L — depending on how porous the stone is | 4–5 m²/L — depending on how porous the stone is |
| Sizes | 5 L and 20 L | 5 L and 20 L |
| Choose it for | Floors, patios and paving that take foot traffic | Wall cladding and stone where you want no change in appearance |
How to seal slate and sandstone floors
- 1 Surface must be dry, clean & free of dust, loose particles and flaking material.
- 2 Apply 5 days after installation with a roller paint brush — it secures even, consistent coverage.
- 3 Saturate the surface; thoroughly inspect and seal all pin-holes & imperfections.
- 4 After 3 hours, test with water droplets — beading confirms sufficient sealer was applied.
- 5 A second coat may be necessary for a satisfactory result.
- 6 Cures fully within 12 hours.
How to seal stone cladding and travertine
- 1 Ensure the surface is free of loose particles, dust & flaking material.
- 2 Apply by domestic spray for a continuous film — a spray bottle works best.
- 3 On tiles and sandstone cladding, apply with a spray bottle or spray pump — it secures even coverage.
- 4 Saturate the surface evenly and leave to dry.
- 5 Thoroughly inspect and seal all pin-holes & surface imperfections.
- 6 Apply evenly — sealer applied poorly can leave a white residue once it dries.
Sealing damp plaster or concrete rather than stone? That needs a different product — Damp Shield is a water repellent for cementitious surfaces that can be over-coated with paint.
Sealing stone: your questions answered
Which natural stones need to be sealed?
How soon after tiling can I seal natural stone?
How do I know if my stone needs resealing?
How much sealer do I need?
Why has my sealer left a white residue?
Does sealing change the colour of the stone?
Buying stone? Seal it once, properly.
Tell us the stone and the area and we’ll add the right sealer, in the right quantity, to your quote.
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