A guide to sealing an interior limestone tile floor

This guide explains how to seal a limestone tiled floor. Ideally, you should read the associated article regarding cleaning limestone tiled floors.

To view individual product pages, click on the product highlighted in blue. Alternatively, the links for all our articles and products for limestone are at the foot of the page. This will provide further information on prices and container sizes.

The sealing of limestone tiles can be carried out before or after the floor has been grouted. We will discuss sealing older limestone tiles after they have been deep cleaned. And also pre-sealing limestone tiled floors prior to them being grouted (to help with the removal of grout haze)

If you have grey or black limestone, we have produced other guides for cleaning and sealing this type of limestone. Black/grey limestone is treated quite differently from pale limestone (particularly when selecting a sealant). See the links at the foot of the page.

Sealing limestone tiled floors which have already been grouted

We recommend sealing all limestone tiled floors with an impregnating sealer. This kind of sealer sinks into the stone and seals from within. Impregnating sealers are fully breathable and usually do not alter colour or create a sheen.

Interior limestone tiles are almost always sealed with impregnating sealers. Impregnating limestone sealers can be applied to floor tiles, wall tiles, lintels and are also suitable for use in wet areas.

Floorseal Premium Impregnating Sealer is the ideal premium sealer for sealing both polished and honed limestone floors. It is non-film forming and will not alter the appearance of the stone.

After the application of this sealer, a matt finish honed limestone will remain as such. Polished limestones will still have their sheen. The sealer should be applied to both the face of the tile and associated grout lines.

Applying Premium Impregnating Sealer to a pre-grouted limestone floor

Impregnating sealers are easy to apply, simply brush or roller the product over the area and allow it to sink into the tile and grout. If any sealer is present on the surface of the tile after 20 minutes you must remove this excess sealer with a microfibre cloth.

On polished or dense limestones, you may wish to remove the excess more quickly. The sealer must not dry on the surface like a skin. Premium Impregnating Sealer is designed to penetrate the surface and sink in. The sealer is ‘in’ the tile not ‘on’ the tile like a film or lacquer.

Therefore, normal impregnating sealers do not alter the appearance of the tile as the sealing polymers sit within the pores of the tile. The sealer will not create an artificial surface sheen as it is not a surface drying film or lacquer.

Once you have successfully carried out the first application (and removed the excess) please apply the sealer again  – approximately 40 minutes after the 1st application.

This timing does not have to be exact but, if possible it should be carried out relatively soon after the first application. This provides the maximum chance of the sealer penetrating the pores of the stone.

During this 2nd application, you will find less of the product is required as the first application is already taking effect. Wipe all excess sealer away as before with clean microfibre cloths. The 2nd application is simply to fill in any areas you had not fully saturated during the 1st application.

For polished surfaces, less product is required, particularly during the 2nd application. Polished surfaces have a higher degree of surface tension than honed limestone tiles. For this reason, greater coverage rates are achieved when sealing dense or polished natural stone.

Applying Premium Impregnating Sealer to an ungrouted limestone tiled floor

There are some differences when applying sealers to ungrouted limestone tiles.

Firstly, you can apply the sealer to the tiles as they are removed from their packaging or pallet. Apply the sealer to the back, sides and front of the tile and allow them to dry and cure. Remove all excess as before.

If you are sealing before fixing the tiles to the substrate seal the sides and back of the tile once. You can apply Premium Impregnating Sealer to the visible upper surface twice as normal.

Pre-sealing your tiles will make the removal of grout easier. The potential issue with limestone is that you should not remove grout haze with a normal acid-based cleaner. Acids will attack and therefore damage the limestone tiles whilst removing the haze.

Pre-sealing reduces the likelihood of grout haze issues. The tile will resist the grout and water used to remove the haze once sealed. You must still work carefully when grouting a limestone tiled floor regardless of whether you have pre-sealed or not!

An alternative pre-sealing method is to seal the upper surface after the tile has been fixed to the floor. You can allow the sealer to travel into the gap between the tiles thereby sealing the sides of the tile as well.

Apply Premium Impregnating Sealer as before in 2 applications and allow the sealer to dry and cure.

Once the tiles are fitted and grouted (and allowed to become fully dry) you can apply more sealer to the face of the tiles. You may not be able to encourage much more sealer into the face of the tiles, but the sealer will certainly penetrate the grout.

In conclusion

Floorseal Premium Impregnating Sealer can be applied to most forms of limestone tile as a non-visible breathable sealer. It will not alter the appearance of the tiles and can be used as a pre or post-grouting sealer.

This sealer is low odour and rapid drying. The coverage rate is approximately 8m2 for the 1st application and 16m2 for the 2nd. Please be aware coverage rates are not ‘fixed’ due to the variances in porosity of any natural limestone tile. This product can be applied to interior limestone floors or walls including wet rooms.

Please Click Here to view all of our products for sealing and cleaning limestone tiles. You will also be able to see all of our handy ‘how to’ guides relevant to interior & exterior limestone.

If you have a black or grey limestone, please Click Here to view the products and guides for this particular kind of limestone. Black limestones are treated a little differently than pale/cream-coloured limestones.

The information contained within this article is not exhaustive. If you need further information please contact Floorseal on (01484) 861461 or email us Info@floorseal.co.uk our web address is www.floorseal.co.uk.