One of the biggest problems with Black Limestone is it's acid sensitive nature and we have seen a number of occasions where acidic patio cleaning products have ruined the appearance of the stone leaving it looking washed out. Another common issue is the application of sealers designed for internal use which cannot cope with the weather conditions.

Maintaining External Unsealed Black Limestone

 Apply Tile Doctor Pro-Clean diluted 1:3 with water and leave to dwell for ten mintutes. Then scrub the Pro-Clean into the stone with a Black buffing pad fitted to a rotary floor machine. Remove the resulting slurry with a wet vacuum and rinse down the stone with water a few times to remove and remaining solution. Leave to dry off overnight.

Maintaining External Sealed Black Limestone

 Use a coarse 200-Grit Diamond pad attached to a buffing machine lubricated with water where required to remove the sealer and clean up the stone.

 Remove the slurry with a wet vacuum and then continue with a 400-Grit No.1 Red burnishing pad to close the pores. Again apply with water and remove the slurry with a wet vacuum.

 If there is any flashing (old sealer) still in place then use Tile Doctor Remove and Go on these areas, scrub and rinse with water after a five to ten minute dwell time.

Acid Damaged Black Limestone

 Start with a coarse 100-Grit Diamond milling pad attached to a weighted buffing machine, 50 to 55kg of extra weight is perfect for this as it will enable the pad to dig deeper into the rougher texture of the stone and resurfce the damage caused by the acid. Again lubricate with water where required and remove the slurry with a wet vacuum.

 Next apply a 200-Grit Diamond pad attached to a buffing machine to further refine the surface of the stone. Lubricate with water where required and remove the slurry as before with a wet vacuum.

 Continue to refine the surface of the stone with a 400-Grit No.1 Red burnishing pad to close the pores. Again apply with water and remove the slurry with a wet vacuum. If there is any flashing (old sealer) still in place then use Tile Doctor Remove and Go on these areas, scrub and rinse with water after a five to ten minute dwell time.

Sealing Black Limestone

 A sealer should only be applied when the stone is fully dry so you may need to wait until the weather improves before applying a sealer. If your unsure use a damp meter to measure the mositure level in the stone. To seal apply one coat of Tile Doctor Colour Grow, its a penetrating colour enhancing that will protect the stone, intensify the black colour and is rated for external use.

Sealing Acid Damaged Black Limestone

 Black Limestone is naturally Black due to its high oil content; however, this can leach out as the seasons take their toll turning the stone grey or a lighter shade of black. To restore colour and add protection we recommend the application of Tile Doctor X-tra Seal which has a unique breathable oil-based resin formula which provides a low satin finish and unlike most outdoor sealers on the market has the added benefit of UV light protection.

PLEASE NOTE: A sealer should last several years when used externally but can be impacted by the use of strong chemical cleaners, steamers, direct lance pressure washing and periods of temperatures below -5°c.

Internal Wall & Floor Tile Maintenance

For internal Wall & Floor Tile Maintenance including cleaning, polishing and sealing please treat in the same way as normal Limestone. Full details on the maintenance of Limestone can be found on our Limestone maintenance page.

Regular Maintenance of Black Limestone

For the regular cleaning of Black Limestone use a sealer friendly cleaning product such as Tile Doctor Stone Soap which has been especially formulated for the regular cleaning of Sealed Stone and Tile surfaces keeping them fresh.

For many examples of Limestone cleaning and sealing activities carried out by UK Tile Doctors including Black Limestone please visit http://limestone.tilecleaning.co.uk

Recommend Limestone Cleaning Products

When using our products please take time to familiarise yourself with the directions on the back of the bottle first.