Limestone is a fabulous floor finish, providing a surface that’s really hardwearing and very easy to maintain. Like many other natural materials, a limestone floor will need to be sealed after installation. In this blog, we look at the different sorts of treatments available and method of application.
Why does limestone need to be sealed?
Limestone is a sedimentary rock that’s formed primarily of calcium carbonate.
Limestone floor tiles vary greatly in colour, from light to dark, and in texture and finish – from a honed, uniform surface, to a rustic tile scattered with fossils.
All stone is naturally porous and application of a sealer will protect the surface from staining. One of the best sealers that we recommend is a treatment from LTP’s ECOPROTECÒ range.
What are the benefits of sealing limestone?
Application of a sealer provides lots of benefits.
It protects the stone and makes ongoing maintenance easier. Most tiles are sealed after installation but some may need to be ‘pre-sealed’ beforehand; this protects the surface from being marked during installation and eliminates ‘picture-framing’ caused by grout bleeding into the stone.
Check to see if a pre-seal is recommended for your tile.
Different types of sealer
There are lots of different types of sealer and they generally fall into two categories – spirit-based, which are often described as ‘solvents’, or water-based. Some sealers are coating-type treatments which bond onto the stone surface, whilst ‘impregnators’ penetrate into the stone.
Most treatments have a natural appearance but some are designed to enhance or restore the colour of existing tiles.
Spirit-based or ‘solvents’ v water-based
Spirit and water-based sealers function in a similar way. They’re both tough, durable and provide stain protection.
Once a surface has dried, spirit evaporates into the air and releases VOCs into the atmosphere; it doesn’t actually contribute to a treatment’s ongoing performance.
Water-based treatments enter a stone’s porosity in the same way but as they tend to be VOC-free, they don’t have the same negative impact.
For this reason, we always recommend water-based treatments.
As well as offering high performance, with low VOCs and low odour, quality water-based sealers can be applied over residual moisture, making treatment of limestone pavers far more feasible year-round.
Water-based treatments are also generally UV-resistant, so they won’t ‘yellow’ and they tend to go further than spirit-based sealers, with a typical extra coverage of between 10% and 20% on most surfaces.
If you’re sealing a floor that runs through bi-fold doors, look out for a treatment that offers additional protection for the external stone – against the elements, and frost, lichen and algae, etc.
Always clean before you seal!
Before you seal a tile, it’s really important that the surface is thoroughly cleaned.
Here is how to clean limestone floor tiles.
This allows the treatment to be properly absorbed into the stone’s porosity. If dirt and residues are left in place, they’ll become sandwiched between the stone and sealer.
If dirt residues remain on the surface of the tile it will stop the sealer from penetrating and will compromise the protection, will make the surface look patchy and ongoing cleaning more difficult.
This very important stage is often referred to as the ‘builder’s clean’ or ‘initial clean/wash’.
How to apply limestone sealer
We have based the details below on application of the treatment that we recommend – ECOPROTECÒ Natural Finish Stone Sealer. If you’re using a different product, please refer to the instructions.
- Make sure that your limestone is completely clean, dry and free from dirt, grime, cement and grout. If necessary, clean with a dilute solution of ECOPROTECÒ Stone & Tile Intensive Cleaner 1:10 and white pad. Rinse well to remove residues and leave to dry (24hrs)
- For rough cut, tumbled, textured or riven surfaces: Shake bottle before use. Apply generously and evenly using a foam roller or paint brush. On more absorbent surfaces, apply further coats at hourly intervals until the surface is fully saturated.
- For honed, smooth and polished surfaces: Shake bottle before use. Apply liberally and evenly using a sealant applicator pad, lint-free cloth, lamb’s wool applicator or sponge. Leave surfaces to dry. Remove any residual sealer if still visible after one hour.
Do not use a sprayer to apply. On vertical surfaces apply from the bottom up.
When should I reseal my tiles?
All natural limestone tiles will begin to show signs of wear and patches of ingrained dirt after around 3-5 years. How often you will need to reseal your limestone floors will vary depending on where your tiles are laid; areas like bathrooms and cloakrooms will wear more slowly than high traffic areas, like kitchens, hallways and boot rooms.
How can I test if my tiles need sealing?
The quickest way to see if your sealer is still performing is to carry out a water test.
If you drop a bead of water onto the surface and sits in place, it is well sealed. If the water quickly soaks in or makes the surface look darker, then it needs resealing.
To top up protection, give the tiles a thorough clean with ECOPROTECÒ Stone & Tile Intensive Cleaner, allow them to dry and then apply a coat of ECOPROTECÒ Natural Finish Stone Sealer.
If you want to enhance the colour of your limestone, other sealing options include ECOPROTECÒ Colour Enhancing Stone Sealer.
Cleaning & ongoing maintenance of limestone tiles
It’s really important to use the correct cleaning product, to keep your tiles looking good. It will also double the life of your protective sealer. For tips on routine and deep cleaning, please see our blog on How to clean limestone floors
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