Here at Wellington Tile we quite often get asked, why do i need to seal natural stone? Natural stone like Terracotta, Slate, Polished Porcelain & Quarry Tiles ect.
Well its because they are Naturally porous, and if left unsealed every piece of dirt and grime will be absorbed by your natural stone, giving you a really big clean up job, to prevent this from happening we would definitely recommend sealing them.
There are essentially three aims when sealing a tile.
- Stain Prevention
- Surface Protection
- Surface Enhancement
It is not always possible or indeed necessary to achieve all the aims, however stain prevention tends to be the overriding aim.
To achieve these aims there is the choice of two types of sealers
These will either be spirit based or water based.
These two types of sealers can be used independently or together depending on the type of surface being sealed and depending on the type of finish required:
Essentially there are three types of finish:
The first two are achieved with impregnating sealers, and the third with Surface sealers
Unsealed, most natural tiles are absorbent to some degree or other, just pour a tea
spoon of water on to an unsealed tile and observe how quickly the water is absorbed. English Limestone, Sandstone, Marble and Terracotta tend to be the most absorbent and denser surfaces such as Granite and basalt? Much less absorbent, Travertine and Slate sit somewhere in the middle.
Full bodied Porcelain and Quarry Tiles may seem highly vitrified, but they can still be absorbent. On the whole the cheaper the tile here, the more absorbent it is likely to be..
Tiles have small pin-holes and open fissures as part of its natural texture. This texture will tend to accumulate grit and stains as part of the natural wearing process and unless they are impregnated will cause the floor to stain.of water on to an unsealed tile and
An impregnating sealer will have a carrier, often white spirit and a sealer within it. Once absorbed the carrier evaporates leaving the sealer in situ protecting the tile just below the surface
Depending on the porosity of the tile, a second or third coat of sealer may be needed.
In some cases a secondary seal is required to protect the surface of the tile, or to give the surface a gloss or satin finish.
Impregnating sealers are absorbed into the tile sealing it just below the surface, they tend not to alter the characteristic of the tile and whilst they offer mechanical strength to a tile and in some cases ..colour enhancement.., they will not offer surface protection.
To achieve surface protection and a different finish to the tile , a surface sealer is used, these will provide the tile with a gloss or satin finish. In this case clearly the natural look of the tile is being altered.
As a general rule surface sealers tend to be water based, rather than spirit based and
depending on the nature of the surface being sealed can be used on their own or in conjunction with an impregnating sealer.
Advantages and disadvantages of Spirit Based & Water Based Sealers
Spirit based and water based sealers now perform equally well provided you purchase a water based sealer rather than a water based water repellent.
In our experience whilst water based impregnating sealers are becoming more widely used for environmental reasons, spirit based sealers are still much more popular for the simple reason: they are easier to apply. Spirit is a better carrier than water, so spirit based sealers transport the sealer deeper into a tile.
However, as with paints the trend is away from solvent/spirit based products to waterbased sealers.
Another reason for considering waterbased sealers is they have much less odour than spirit based sealers.
External Use: Swimmimg Pool surrounds: Wet Rooms:
In most circumstances impregnating sealers will be breathable allowing use in wet area’s and outside.
This is not always the case with surface sealers:
Whether they are polyurethane varnishes or waterbased; surface sealers are not breathable and should not be specified for wet area’s or externally.
Everything above applies to grout joints as well as tiles. So remember to seal the grouting as well to achieve a perfect durable finish for your tiled surface with LTP Grout & Tile Protector.