How do I remove white marks (Calcium Carbonate Deposits) from the surface of Slate

DESCRIPTION:  Slate is basically squashed mud and silt from ancient oceans and river beds subjected to tremendous pressures in a hot environment deep underground. Eventually being forced to the surface by the collision of continents. Slate is hundred’s of million’s of years old. It is possible to get deposits of limestone and marble pebbles or stones, which crush between the layers of silt and then harden to form a calciferous deposit. This is normally visible on the surface of slate after it has been split. It is not a defect, but a natural characteristic of the stone. Aesthetically these deposits are not always appealing, so the following is a guide, which should help aid their removal.

LTP Grout Stain Remover or LTP Cement, Grout & Salt Residue Remover is applied to the surface.

The moment it makes contact with the calcium carbonate deposit it begins to dissolve.

Agitating the surface using a black emulsifying pad aids removal without damaging. Make sure to clean the whole surface and not just the deposit. Rinse well with plenty of water.

Once dry the surface is sealed with LTP Colour Intensifier and Stainblock.

After treatment the slate should appear darker. This also helps to further disguise the blemish that is left following the removal of the calcium carbonate deposit.

Sealed surfaces should be maintained with a mild PH detergent such as LTP  Waxwash.

Repeated use of stronger detergents for maintenance can cause un-necessary damage.

INITIAL CLEANING: LTP GROUT STAIN REMOVER OR LTP CEMENT, GROUT & SALT RESIDUE REMOVER     1ltr & 5ltr

• This should be done after fixing and before sealing and grouting to remove calcium carbonate deposits, dust and dirt that have accumulated during the production and fixing process.  Apply undiluted solution to the surface of the stone and agitate immediately with an emulsifying pad. Rinse thoroughly with a separate pot of clean fresh water. Wipe away the released calcium dirt and grime with a mop or sponge and water and leave to dry for 24 hrs

https://www.ltp-online.co.uk/prod/ltp-grout-stain-remover

https://www.ltp-online.co.uk/prod/ltp-cement-grout-and-salt-residue-remover

SEALING:  LTP COLOUR INTENSIFIER           500ml, 1ltr & 5ltr

• Before grouting apply a coat of LTP Colour Intensifier & Stainblock, check that all of the sealer has been fully absorbed within 40 minutes, any excess that remains on the surface after 40 minutes should be worked in with a soft cloth or buffing machine. Leave for a further 4 hours or overnight before grouting the joints. Once all residual grout has been removed and the surface and joints are thoroughly dry; apply a final coat of sealer covering the joints as well. Buff to remove any excess within 40 minutes and then leave for a minimum of 3 days to fully harden before making excessively wet.

https://www.ltp-online.co.uk/prod/ltp-colour-intensifier-and-stainblock

MAINTENANCE:               LTP WAXWASH                            1ltr & 5ltr

DAILY/WEEKLY

• Add 1 cap full of LTP Waxwash per litre of warm water. Apply to the surface with a mop to remove daily dirt and leave to dry. Does not require rinsing.  Using the correct low ph maintenance cleaner will help to increase the life of the seal.

https://www.ltp-online.co.uk/prod/ltp-waxwash

IMPORTANT NOTES:

When cleaning or sealing vertical surfaces start at the top and work down.

Provided the surfaces are correctly sealed and maintained protection should last 4 – 5 years before considering applying a top up coat. Sealing will not prevent wear from abrasion.

After Intensive cleaning to remove any ingrained dirt or other staining and once dry, always test for moisture ingress. If evident cleaned areas should be re-sealed.

When using LTP Grout Stain Remover or LTP Cement, Grout & Salt Residue Remover, gloves should be worn and ensure you fully read & understand the directions for use.

For detailed application instructions please see Technical Data Sheets.

Protecting encaustic tiles – before & after grouting

Encaustic tiles have a timeless appeal and they’re available in so many different styles – from modern geometrics to traditional curlicues. Authentic designs are made by hand, using traditional frames and moulds; a mix of natural marble powder, cement and coloured pigments creates the surface pattern and the tile’s generally have a sand and cement backing. As a result, they’re porous and can easily become stained, so they will need to be sealed before and after grouting.

Before sealing, we recommend a thorough clean with LTP Grimex, using a 1:10 dilution. This applies to both newly laid and renovation projects. It’s also important not to use an acid-based detergent; encaustic tiles are sensitive to acid, which can etch the surface and damage the grout joint – and the sealer once the tile has been protected.

When it comes to sealing there are various options available, depending on the look that you want to achieve. Impregnating sealers LTP Mattstone or the water-based equivalent LTP Mattstone H20 are popular, as they protect the tile without altering the appearance. Depending on the type of encaustic tile being used, up to three or four light coats of sealer might be needed. Always test on an inconspicuous area first and buff off any excess.

LTP Colour Intensifier is also popular, as it enhances colour and will bring out the different tones within the tile. Like Mattstone, it’s also an impregnator, so it will allow the tile to breathe. For ongoing maintenance, we recommend LTP Waxwash.

A correctly sealed and maintained encaustic floor should last three to four years before resealing is needed.  For more information, please follow the link: Encaustic Tiles guide

To find out more, please call LTP on tel. 01823 666213, email info@ltp-online.co.uk or visit https://www.ltp-online.co.uk

PROBLEMS WITH STEAM CLEANING LIMESTONE

Water-based steam cleaning may seem like a fast and efficient way to keep a stone floor spotless but repeated use of super heated water can potentially cause issues. These include residual staining, mobilisation of salts and corrosion of hidden particles of Iron within some limestone surfaces.

Surface of a Limestone magnified by 120 microns

Steam can penetrate the small cracks and fissures on the surface of the limestone.
This will clean the limestone, but will also embed water into the surface.
Repeated cleaning using a steam cleaner can activate salts and weaken the stone over time. This can also lead to spalling or fragmentation of the surface.

 

COMPROMISED IMPREGNATING SEALER?
Surfaces that have been treated with an impregnating sealer can also be compromised. Steam cleaning doesn’t normally remove the finish but repeated use can expose new fissures and capillaries within the stone. The newly exposed and unsealed surface takes in more dirt and becomes harder to clean, so then requires more frequent cleaning. This increase in cleaning can then, in turn, exacerbate the problem.

SURFACE SEALER DAMAGE?

Topical sealers used to finish the surface of stone can also be damaged. Steam is often used to remove paints, wall papers and other
coatings from surfaces. If a film-forming
sealer has been used then the steam can cause a partial separation of the seal from the surface of the stone, causing it to turn white or opaque.

                                                                       
RUST STAINS ON THE SURFACE?                                   Rust stains are reddish-orange and are caused by the oxidation (rusting) of iron. The source of iron staining is normally from within the stone, as most of the iron on the surface is normally removed or discarded at the point of fabrication by the quarry. Therefore, most Iron remains hidden and within the stone rather than on it. However, water from steam cleaning penetrating through natural fissures in the  stone can activate or accelerate rusting.

CRUMBLING OF THE SURFACE?
Moisture from repeated steam cleaning can, in some
cases, cause spalling or fragmentation of the surface.
The migration of salts from moisture in the limestone can promote crumbling of the surface causing larger fissures and craters to appear. This is more
common in limestone and marble that contain naturally occurring mud or calcite veins which are more vulnerable to this issue.

WHAT TO DO?

COMPROMISED IMPREGNATING SEALER: Intensively clean the surface of the stone with LTP Grimex. Leave overnight to dry. Re-apply impregnating sealer – LTP Mattstone H2O or LTP Colour Intensifier & Stainblock H2O. For routine aftercare use LTP Waxwash. This is a PH neutral cleaner that will not damage the stone or compromise the seal.

SURFACE SEALER DAMAGE: Remove the film forming sealer using LTP Grimex or LTP Solvex. Leave overnight to dry. Re-apply the film forming sealer – LTP Ironwax Satin or LTP Ironwax Gloss. For routine aftercare use LTP Floorshine. This gentle detergent will clean the stone and repair the seal where it has worn from abrasion every time the floor is washed.

RUST STAINS ON THE SURFACE: Intensively clean the surface of the stone with LTP Power Stripper or specialist treatment, LTP Ferrex. Leave overnight to dry. Re-apply impregnating sealer, as above. For routine aftercare use LTP Waxwash. 

CRUMBLING OF THE SURFACE: Intensively clean the surface of the stone with LTP Grimex. Leave overnight to dry. Use a suitable colour-matched resin stone filler to fill in the voids. Re- hone the surface of the stone using a twister pad and sponge down with a little water to remove any dust or sediment. Leave to dry. Re-apply impregnating sealer, as above. For routine aftercare use LTP Waxwash. 

This information is offered without guarantee.  The material should be used so as to take account of the local conditions and the surfaces to be treated.  In case of doubt, the product should be tried out in an inconspicuous area.