Sealing Stone Outside

Limestone, Sandstone, Travertine, Marble, Slate, Granite, concrete:
Regardless of what type of flooring you choose, the likelihood is it will require some form of sealing.

This is because natural stone is porous, and therefore if left unsealed, any moisture will be soaked up by the stone making it very difficult to remove, and potentially leaving the surface permanently stained (sometimes even fallen leaves can cause stains).

The best way to prevent all this is to seal the stone.

When you seal a stone, you are essentially filling any voids or pores of the stone with the sealer. This prevents any further liquid to absorb in to the tile, as demonstrated here with this close up shot of a water droplet on a tile sealed with LTP Mattstone.

When sealing natural stone outside it is important to use a breathable impregnating sealer, this will allow the transition of moisture from underneath.
Examples include LTP Mattstone H20 which will leave the stone looking as it does naturally. And LTP External Stone Sealer which will enhance any natural colour in the stone, both of these are water based breathable sealers and will require 24 hours to cure.

It is important to note that all stones located outdoors are susceptible to a condition known as efflorescence.
This blooming is caused by water moving through the substrate of a material and carrying minerals and salts found in the mortar bed, grout, soil or the stone itself.
We have a blog here all about efflorescence.

Its also very important when laying Natural stone to make sure that its fixed on a full bed of adhesive and not spot fixed.
The end result could look like this if its spot fixed.
Spot fixing issue Sandstone

If this has already happened to your patio, we have a blog here.

When sealing different natural stones, what will vary the most will be how many coats the stone will need before it is fully sealed.
Each stone exhibits different levels of porosity. A tumbled Limestone may have a higher porosity level than a Honed and filled Limestone.

Sealing natural stone with Mattstone H20 

Shake bottle before use.

Test the porosity of your stone with water and a teaspoon, using the LTP porosity test.

Once surfaces are clean and dry, apply the product to the surface evenly using a sealant applicator pad, brush or soft cloth.

When sealing its important not to over apply the sealer and redistribute excess, avoid letting the sealer pool on the surface, as this can cause white marks to appear on the stone when it dries.
On highly absorbent surfaces apply several coats wet-in-wet.
After 15 minutes, remove any excess sealer with an absorbent cloth. Do not allow residues to dry on the surface.
Do not walk on the surface for 3 hours and protect from wet conditions for 3 days.

Sealing Stone With LTP External Stone Sealer.

Shake bottle well before use. Apply evenly to the surface using a foam roller or paint brush. On more absorbent surfaces apply further coats at hourly intervals until the surface is completely saturated. Remove any residual sealer if still visible after one hour

Cleaning Tiles Outside

Before you start sealing your stone it is important to make sure your stone is clean and dry, other wise you will just seal in dirt and grime.

Old layers of sealer, dirt residues and light deposits of organic matter and algae must be removed from the surface and pores of the stone.

This can be done by either using LTP Grimex which is a intensive cleaner or LTP Mouldex Paving Cleaner.

To Clean with LTP Grimex, dilute 1:3 with water, apply to the surface with a sponge or water brush and leave to sit on the surface of the tiles for as long as it takes for the dirt to release. (5-30 minutes depending upon the level of dirt). If areas look as if they are drying out just add a little more solution to keep the area wet.

Agitate the surface with a stiff deck brush after approx 10 minutes (scrubber machines can be used).

Continue to scrub while adding clean water. Remove residues from the surface with water or scrubber machine.

Rinse thoroughly with clean fresh water to remove all remaining residues. Use a power washer if necessary.

Allow the surface at least 24 hours to dry before sealing.

To clean with LTP Mouldex Paving Cleaner, Shake well before use.
Surfaces to be treated should be completely dry before application.
Pour solution undiluted directly onto the pavers and spread out evenly using a sponge or paint brush, Garden sprayers can also be used and leave for a minimum of 1 hour.

Apply a little water and agitate with a stiff Deck brush or emulsifying pad to release the dirt and grime, and then rinse thoroughly using a hose or jet wash.
Some stubborn stains and black spot may require a longer treatment, in which case apply and leave on surfaces overnight. If some black spot remains after treatment, It should fade and disappear after a few days following the treatment. If not: re-apply. Keep pets off at all times during treatment. In case of contact with metals, fabrics and painted surfaces rinse with water immediately. Do not use on warm surfaces. Do not apply if rain is imminent. Avoid contact with ponds & plant life: if contact is made rinse well with plenty of water.

General Maintenance.
Weekly or daily depending on conditions, use a hose and a brush to remove any debris that may be lying on the stone.
Then annually if required use LTP Grimex, this will remove surface dirt and grime, possibly every 6-12 months depending on condition.
Dilute Grimex 1:3 parts water and apply the solution on to the surface and agitate.
Leave for 10 minutes before agitating again and then rinse with water.
Allow 24 hours to dry and then if necessary re-apply a light coat of sealer.

PLEASE NOTE: Always follow the detailed instructions on the product labels. Protect stone surfaces from contact with acidic substances. Do not use abrasive materials on honed or polished stones. Avoid using normal detergents or strong bleach cleaners on sealed surfaces as they will gradually remove the protective seal.

Please note that this information is offered as general guidance only and without guarantee. Your specific circumstances may need an alternative approach. In case of doubt, any process should be tried out in an inconspicuous area before general application.

Problem Solving Black Limestone

We are often contacted in particular about black limestone, the appearance of stains and mineral deposits is not uncommon and occurs with most types of limestone, however the appearance on black limestone or darker stone is more prevalent. This is why it is possible to notice some marks appearing even before sealing. As a naturally occurring chemical reaction it is often difficult to avoid. So this blog is all about some of the different things that can happen, what you can do to prevent it or what you can do to resolve the issues as best you can.

Mineral Stains

Mineral deposit stains on black limstone

Mineral stains are sometimes caused when rain water trickles through sand-cement mortar screeds, toppings and bedding under limestone paving can become moderately alkaline. As this rainwater evaporates, its alkalinity increases until the solution becomes saturated.
This solution then can travel to the surface within the limestone where it starts to deposit solids such as white and grey encrustations of calcium carbonate also known as lime plumes.
To remove the the mineral salts from the surface wash the surface with a mild solution of acid*. This will help disperse the mineral salt deposits from the surface.
LTP Grout Stain Remover is a product suitable for the task, dilute 1 part LTP Grout Stain remover in 4 parts warm water and apply to the surface of the stone. Agitate using an emulsifying pad or similar abrasive pad and then rinse thoroughly with plenty of clean water. Repeat process if necessary.
For more information about LTP Grout Stain Remover please see the Technical Data Sheet.

*N.B Grout stain remover may etch the surface and cause the stone to dry lighter.
If the Limestone is either Honed or Polished do not use LTP Grout Stain Remover and instead use LTP Powerstripper.

Mineral deposits causing a banding effect

Halo Stains & Bands Of Mineral Deposits.

This is caused by trace amounts of sodium and potassium oxides within the Limestone which can also be activated by rain water. Even where rain is slightly acidic, the solutions of these salts in rainwater will gradually become alkaline. Surface wetting and evaporation can produce recurrent patches and bands of dampness known as accumulation zones ( rainwater pooling on the surface where it cannot run off).

Evaporation concentrates the alkaline solutions until they become saturated at the  outer limits or edge of accumulation zones. Further evaporation then causes precipitation, crystallisation and immobilisation of the salt at the surface and in pores immediately below the surface. The resulting bands of distinct pigmentation are halo stains as seen in the image above of Limestone.

Grout & Adhesive Stains.

img_0122

Adhesive Stains On Limestone

Grout and adhesive stains like this appear often, if the stone has been sealed beforehand then the process of removing the residues is easier.
After grouting most of the residues should be taken off with water before it fully dries on the surface. For the removal of most grout residues on Limestone we would recommend using LTP Powerstripper. However on more severe cases as shown in the picture above, using a mild solution of LTP Grout Stain Remover may be more effective.
Grout Stain Remover is an acid based cleaner and will etch any acid sensitive surfaces (Limestone, marble, some sandstones, chrome etc).
We would always recommend to test on a small inconspicuous area first.
LTP Grout Stain Remover Tech Data Sheet.

General Dirt & Grime

If your limestone has been outside for a couple of years, it may have seen better days.
General dirt and grime can be easily removed with LTP Grimex.
Dilute in a bucket of water as per instructions on the back of the bottle, then apply and leave for 10 minutes. Give it a scrub with a deck brush or an emulsifying pad and then rinse with plenty of clean water.
After cleaning allow to dry for 24 hours and then the stone will be ready for resealing.

Protect your Limestone with the correct sealing product.

Sealers used to enhance the appearance and help prevent limestone pavers staining from organic matter outside need to be breathable. LTP Mattstone H20 & LTP Stone Oil are examples of breathable sealers suitable for external use. As well as protecting the stone from staining, breathable sealers will allow the microscopic transition of moisture assisting any trapped moisture to escape through the stone from the mortar and sub surfaces. However, moisture permeating through the stone and sealer to the surface can still dry to leave a calciferous deposit.

Once the stone is thoroughly dry and mineral salt deposits are greatly reduced, general dirt and grime has been cleaned off, reseal the stone with an appropriate limestone sealer. LTP Mattstone H20 is highly effective natural stone sealing solution and is suitable for exterior use. However many of our customers have used LTP Stone Oil after acid washing their stone as it helps to re-enhance and deepen the colour.

Apply LTP Stone Oil to the surface of the stone using a paint brush. Allow it to absorb into the stone and then remove any visible excess from the surface after 45 minutes using an absorbent dry towel. The aim is to completely saturate the stone with as many coats of the sealer as necessary, but do not allow the sealer to dry and leave a film on the surface. Do not apply in direct sunlight.
For more information on how to apply please see the Technical Data Sheet.

LTP Mattstone H20 is applied to the surface with a paint brush, allow to absorb for 15 minutes and then apply a second coat. Remove any visible excess on the surface after 45 minutes.
For more information on how to apply please see the Technical Data Sheet.

 

Please note that this information is offered as general guidance only and without guarantee. Your specific circumstances may need an alternative approach. In case of doubt, any process should be tried out in an inconspicous area before general application. 

Sealing Stone Outside.

Limestone, Sandstone, Travertine, Marble, Slate, Granite, concrete:
Regardless of what type of flooring you choose, the likelihood is it will require some form of sealing.

This is because natural stone is porous, and therefore if left unsealed, any moisture will be soaked up by the stone making it very difficult to remove, and potentially leaving the surface permanently stained (sometimes even fallen leaves can cause stains).

The best way to prevent all this is to seal the stone.

When you seal a stone, you are essentially filling any voids or pores of the stone with the sealer. This prevents any further liquid to absorb in to the tile, as demonstrated here with this close up shot of a water droplet on a tile sealed with LTP Mattstone.

When sealing natural stone outside it is important to use a breathable impregnating sealer, this will allow the transition of moisture from underneath.
Examples include LTP Mattstone H20 & LTP External Stone Sealer both are water based breathable sealers and ideal for use outside.

It is important to note that all stones located outdoors are susceptible to a condition known as efflorescence.
This blooming is caused by water moving through the substrate of a material and carrying minerals and salts found in the mortar bed, grout, soil or the stone itself.
We have a blog here all about efflorescence.

Its also very important when laying Natural stone to make sure that its fixed on a full bed of adhesive and not spot fixed.
The end result could look like this if its spot fixed.
Spot fixing issue Sandstone

If this has already happened to your patio, we have a blog here.

When sealing different natural stones, what will vary the most will be how many coats the stone will need before it is fully sealed.
Each stone exhibits different levels of porosity. A tumbled Limestone may have a higher porosity level than a Honed and filled Limestone.

Sealing natural stone with Mattstone H20

Shake bottle before use.

Test the porosity of your stone with water and a teaspoon, using the LTP porosity test.

Once surfaces are clean and dry, apply the product to the surface evenly using a sealant applicator pad, brush or soft cloth.

When sealing its important not to over apply the sealer and redistribute excess, avoid letting the sealer pool on the surface, as this can cause white marks to appear on the stone when it dries.
On highly absorbent surfaces apply several coats wet-in-wet.
After 15 minutes, remove any excess sealer with an absorbent cloth. Do not allow residues to dry on the surface.
Do not walk on the surface for 3 hours.

Sealing natural stone with External stone sealer.
Apply evenly to the surface using a foam roller or paint brush. On more absorbent surfaces apply further coats at hourly intervals until the surface is completely saturated. Remove any residual sealer if still visible after one hour.

Cleaning Tiles Outside

Before you start sealing your stone it is important to make sure your stone is clean and dry, other wise you will just seal in dirt and grime.

Old layers of sealer, dirt residues and light deposits of organic matter and algae must be removed from the surface and pores of the stone.

This can be done by either using LTP Grimex which is a intensive cleaner or LTP Mouldex Paving Cleaner.

To Clean with LTP Grimex, dilute 1:3 with water, apply to the surface with a sponge or water brush and leave to sit on the surface of the tiles for as long as it takes for the dirt to release. (5-30 minutes depending upon the level of dirt). If areas look as if they are drying out just add a little more solution to keep the area wet.

Agitate the surface with a stiff deck brush after approx 10 minutes (scrubber machines can be used).

Continue to scrub while adding clean water. Remove residues from the surface with water or scrubber machine.

Rinse thoroughly with clean fresh water to remove all remaining residues. Use a power washer if necessary.

Allow the surface at least 24 hours to dry before sealing.

To clean with LTP Mouldex Paving Cleaner, Shake well before use.
Surfaces to be treated should be completely dry before application.
Pour solution undiluted directly onto the pavers and spread out evenly using a sponge or paint brush, Garden sprayers can also be used and leave for a minimum of 1 hour.

Apply a little water and agitate with a stiff Deck brush or emulsifying pad to release the dirt and grime, and then rinse thoroughly using a hose or jet wash.
Some stubborn stains and black spot may require a longer treatment, in which case apply and leave on surfaces overnight. If some black spot remains after treatment, It should fade and disappear after a few days following the treatment. If not: re-apply. Keep pets off at all times during treatment. In case of contact with metals, fabrics and painted surfaces rinse with water immediately. Do not use on warm surfaces. Do not apply if rain is imminent. Avoid contact with ponds & plant life: if contact is made rinse well with plenty of water.

General Maintenance.
Weekly or daily depending on conditions, use a hose and a brush to remove any debris that may be lying on the stone.
Then annually if required use LTP Grimex, this will remove surface dirt and grime, possibly every 6-12 months depending on condition.
Dilute Grimex 1:3 parts water and apply the solution on to the surface and agitate.
Leave for 10 minutes before agitating again and then rinse with water.
Allow 24 hours to dry and then if necessary re-apply a light coat of sealer.

PLEASE NOTE: Always follow the detailed instructions on the product labels. Protect stone surfaces from contact with acidic substances. Do not use abrasive materials on honed or polished stones. Avoid using normal detergents or strong bleach cleaners on sealed surfaces as they will gradually remove the protective seal.

Please note that this information is offered as general guidance only and without guarantee. Your specific circumstances may need an alternative approach. In case of doubt, any process should be tried out in an inconspicuous area before general application.

 

Has your Natural Stone been damaged by Household Cleaner?

We were contacted recently by a customer whose pet had a little accident on their Stoneworks Tumbled Pietra Limestone and tried to remedy it by spraying CIF Bathroom cleaner on it, the result is shown in the photo below!

Stone damaged by Cif Spray

Stone damaged by Cif Spray-Image supplied by Stone Works Ltd

Our response to help rectify was…………….

LTP Grimex should be used to clean the surface of the stones that have been damaged by the CIF spray. This will help to neutralise the reaction that has caused a change in the character of the stones surface. The Lighter marks will still remain following cleaning, but LTP Grimexshould appear a little darker.

Remember to work on the entire piece of stone and not just the areas that are affected. This should be done in a way that does not allow the cleaning solution to spread over onto neighboring tiles, so whole pieces of stone, but only up to the grout joints.

Apply LTP Grimex diluted 1 : 3 with water and agitate the surface….leave for 10 – 15 minutes….agitate again and then rinse well using a sponge and water.

Leave the stone to dry.

 

Apply LTP Stone Oil to the surface and allow to absorb. Check the surface after 45
LTP-StoneOil5LTin_1L_Grp_Webminutes and then wipe up any excess from the surface. ThisLTP-Mattstone5L,1L_500ml_Grp_Web should be repeated until the colour of the stone has been restored. For extra protection and after a 24 hour curing time for the Oil a coat of LTP Mattstone can be used over the top.

 

LTP-Master500mlSpray_2011_Web

For dealing with spillages quickly when they occur we would suggest LTP Stonewash Spray.
This is a spray and wipe cleaner which will remove spillages without compromising the seal or damaging the surface of the stone.

For daily/weekly mopping use LTP Waxwash. This cleaner is PH Neutral and contains a trace of linseed oil, which makes it ideal for cleaning and embellishing sensitive sealed surfaces. A 1 ltr bottle is enough solution to wash a 20 sq.m LTP-Waxwash1L_Webfloor 40 times.

Hope this helps…

Customers response “Hip hip hooray”

  • It’s worked hooray
    Thank you so much
  • Please thank your guy for his help
    I can’t believe it

Thanks very much again xx

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 products should be tried out in an inconspicuous area before general application.

Natural Stone and Tiles – Common Stains: Water

How to remove Water Stains ­from Natural Stone and Tiles

A water stain mark on natural stone

Natural stone and tiles are an investment that can add real quality to your home or office environment. When staining or marking of a stone surface on a kitchen, bathroom or office floor or work surface occurs, such as water stains; this can create a potentially difficult situation to resolve.

Understand your surface

Ensuring that you know what has caused stains on stone, the material stained and whether the surface is protected can all have a bearing on how you should address the issue. If you are in any doubt it is often more straightforward to seek expert assistance. At LTP we offer FREE technical assistance via our Helpline +44 ( 0) 1823 666213. In most cases, it will be easier to assist you if you are able to supply photographs of the issue and surface. Please send images to info@ltp-online.co.uk with as much information as possible.

Is your stone surface protected?

Natural stone protected with LTP Mattstone

Knowing if your stone surface or tiles has a protective seal applied is important in understanding the best solution to address the issue. Often when a protective seal is in place the method for tackling the problem is much less aggressive and simpler. Essentially this is because the stain is most often only affecting the protective seal.

To protect natural stone and tile surfaces to help prevent staining LTP recommends for following sealing products.  LTP Mattstone or LTP Mattstone H20 for a natural (invisible finish) or LTP Colour Intensifier & Stainblock for an enhanced appearance. LTP Colour Intensifier & Stainblock deepens the colour and enhances the appearance of the stone surface.

Common stains on natural stone and tiles – Water Stains

Water stains can appear on natural stone and tile surfaces such as floors and worktops when water is left to stand, as it dries into the surface it can cause a stain. This is most common with porous stone surfaces such as limestone, flagstones, sandstone and terracotta, but water stains can also affect glazed ceramics, porcelain and polished surfaces such as porcelain, granite and marble.

THE MOST COMMON CAUSES OF WATER STAINS ARE OUTLINED BELOW…

Using the wrong maintenance cleaner can gradually affect the performance of the seal. This after a while allows water to penetrate beyond the seal. In areas of hard water, these water droplets can dry out to leave a lime deposit on the surface. Hard water stains are difficult to remove using normal detergents.

Repeated cleaning of stone surfaces using water and a mild detergent can create a film on the surface.  When we mop and clean our surfaces the water dries off to leave a very slight film of residual detergent. In the months that follow this can create a micron thick film across the surface.  Water droplets can dilute the detergent in the area that they sit on leaving a spot mark.  This all happens on a fairly microscopic level, which is why staining of this nature is sometimes only visible when looking across a surface towards a light source.

The LTP approach to removing water stains

The method that LTP recommends for tackling water stains differs depending upon the surface type.

LIMESTONE, MARBLE, TRAVERTINE AND OTHER ACID SENSITIVE SURFACES

For acid sensitive surfaces, we recommend using LTP Grimex or LTP Power Stripper. Simply wash the area as directed by the label instructions, rinse and allow to dry. Note that if the surface has a protective seal the surface may need re sealing. To make sure that you achieve a uniform finish a wider area may need treatment.

PORCELAIN, TERRACOTTA, SANDSTONE AND OTHER NON ACID SENSITIVE SURFACES

For surfaces that are not acid sensitive, we recommend using LTP Grout Stain Remover. Treat the affected area as directed by the product label, rinse and allow to dry. In some cases you can simply buff the surface to its original shine. Where this is not effective and to help maintenance you may consider applying LTP Glaze Protector.

If the stain persists repeat the treatment, if this is unsuccessful please contact our FREE helpline.

PLEASE NOTE: Always follow the detailed instructions on the product labels. Protect stone surfaces from contact with acidic substances. Do not use abrasive materials on honed or polished stones. Avoid using normal detergents or strong bleach cleaners on sealed surfaces as they will gradually remove the protective seal.

At LTP we believe in helping to offer solutions and this is why we offer a no obligation
LTP TECHNICAL HELPLINE, so please give us a call on +44 (0) 1823 666213 or email info@ltp-online.co.uk and we will be happy to help you.

Visit www.ltp-online.co.uk to buy or find out more about our range of products.

LTP cleaning of natural stone

Cleaning tips for natural stone wall and floor tiles

When is intensive stone or deep cleaning required?

  • As an important stage in the installation process of wall and floor tiles.
  • Where poorly maintained natural stone floor tiles need a top up seal.
  • When restoring natural stone wall or floor tiles.
  • For routine cleaning of unsealed external patios and paved areas.

Why would newly installed wall or floor tiles require intensive cleaning?

Keeping natural stone wall and floor tiles scrupulously clean before and during the fixing process, is vitally important. Intensive cleaning of stone floors and walls before application of the correct protective sealing product will make sure the result does not disappoint. Installing stone flooring and worktops by nature creates grit, dirt and adhesive residues. Ensuring that a vacuum is used (being careful not to scratch the surface) to remove loose dirt from your new stone floor or worktop will not address stains and residue marks. Simply washing stone flooring in water will not be effective in removing ingrained marks or adhesive. Using standard household cleaning products that often contain bleach is likely to damage the surface of your newly installed natural stone floor or wall. You should make sure that the correct cleaning product is used for the natural stone material being installed. Need more information about surfaces? Visit our identify your surface selector.

Selecting the correct intensive cleaning product for your natural stone flooring or wall tiles

LTP has developed a range of four intensive cleaning products that offer intensive cleaning solutions for most commercial and domestic applications. Each of our intensive cleaning products has been designed to address the needs of specific circumstances related to artificial and natural stone. We have solutions for all types of natural and artificial stone flooring, granite countertops and fireplace surrounds. Ensuring you have the correct product for the task by simply contacting our Technical Helpline on +44 (0) 1823 666213.

Removing grout stains1. LTP Grout Stain Remover (1&5 litre containers)

An intensive cleaning solution for removal of cement and grout residues from stone flooring and wall tiles. Extremely effective against mineral salt formations (efflorescence) and the removal of plaster and dust stains. Useful for routine cleaning of unsealed patios and other outside paved areas. LTP Grout Stain Remover may be used on glazed ceramics, quarry tiles, terracotta and some stone. (Do not use on limestone, marble or other acid sensitive surfaces.) Buy LTP Grout Stain Remover

 

 

Cleaning grime from natural stone2. LTP GRIMEX (1&5 litre containers)

The answer to stubborn grime, oil, old layers of wax or acrylic and even rubber sole marks on terracotta and natural stone flooring. Ideal for removing ingrained dirt and grime, both internally and externally. Suitable for use on glazed and unglazed tiles this product is excellent for renovating old quarry tiles, terracotta, slate, stone, marble, stone fireplaces and can be used to clean brick and external paving.
Buy LTP Grimex >>

 

 

Removing oxidised linseed oil3. LTP POWER STRIPPER (1&5 litre containers)

For removing existing layers of sealer from tiles. One of the few intensive cleaning products on the market capable of breaking down oxidised boiled linseed oil and beeswax from the surface of terracotta. Powerful amines, ammonia and alkalinity penetrate and help lift the hardest, heaviest films. Ideal for intensive cleaning of heavily contaminated vitrified quarry tiles, limestone, travertine, sandstone, slate, glazed ceramics and porcelain. Strips most things first time thereby minimising labour costs. Buy LTP Power Stripper >>

Removing tick layers of sealant4. LTP SOLVEX (1&5 litre cans)

A powerful non-caustic stripper that softens most types of solvent based surface sealer, which can then be removed with ease. Suitable for removing most wax, oil, emulsion and polyurethane sealers. Will not discolour or damage natural stone, slate, terracotta or quarry tile surfaces. After washing and rinsing, surfaces are ideal for re-sealing. Buy LTP Solvex >>

How to remove staining from Black Limestone before sealing.

Visible stains on Black Limetone

Visible stains on Black Limetone

After quarrying, milling and then packing a black limestone it is possible for residues of moisture and sediment to remain on the surface. If left over a period of months these deposits of mineral and sediment absorb into the pores of the stone. This type of staining can be very difficult to remove using conventional cleaning materials. The following is a guide to help restore the                                                                                     appearance of the stone using a strong                                                                                   cleaner and then sealing to restore and                                                                                   enhance the colour.

DIRECTIONS FOR CLEANING AND SEALING

1. LTP Grout Stain Remover is applied and 2. GSR scrub immediatelythen immediately scrubbed into the surface using a black emulsifying pad. This should be done for 1 – 2 minutes making sure to cover the whole surface of the stone. This cleaner will slightly etch the surface of the stone to release the stains from within.

 

3. Rinse well with plenty of water2. Do not leave the cleaner to dwell on the surface. Rinse with water immediately after scrubbing. Change the rinsing water every 5 M².
After cleaning leave surfaces to dry for 24 hours.

 

4. Leave to dry
3. Once dry, surfaces will appear grey rather than black. The stains should no longer be visible. The surface of the stone has been conditioned ready for sealing.

 

5. Apply Stoneoil4. Apply a small amount of LTP Stone Oil to the surface of the Limestone and spread out evenly. Leave to absorb into the surface of the stone for 1 hour. Any visible excess after this time work should be worked off using a soft absorbent towel.

6. Spread out evenly

5. The sealer should be left to dry for a minimum of 24 hours with light traffic only.
It will take a further 3 days to reach full hardness, so surfaces should be kept as dry as possible during this time.

INTERIORS
Finishing the stone with a light coat of LTP Mattstone should be considered if the stone is to be used in kitchen areas.

INITIAL CLEANING:                LTP GROUT STAIN REMOVER                   1ltr & 5ltr

This should be done after fixing and before sealing LTP-GroutStainRemover5L&1L_2011_Weband grouting to remove calcium carbonate and mineral deposits including dust and dirt that has 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.

TDS – http://www.ltp-online.co.uk/images/tds-Grout_Stain_Remover.pdf

MSDS – http://www.ltp-online.co.uk/images/msds-Grout_stain_remover_clp_GHS.pdf

SEALING:                                      LTP STONEOIL                                        1ltr & 5ltr

Before grouting apply a light coat of LTP Stone Oil, LTP-StoneOil5LTin_1L_Grp_Webcheck that all of the sealer has been
fully absorbed within 1 hour, any excess that remains on the surface after 1 hour 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 light coat of StoneOil covering the joints as well. Buff to remove any excess within 1 hour and then leave for a minimum of 3 days to fully harden before making excessively wet.

TDS – http://www.ltp-online.co.uk/images/tds-Stone_Oil.pdf
MSDS – http://www.ltp-online.co.uk/images/msds-Stone_oil_clp_GHS.pdf

IMPORTANT NOTES:
When cleaning or sealing vertical surfaces always start at the top and work down.
Provided that the surfaces are correctly sealed and maintained protection should last 3 – 4 years before considering applying a top up coat. Sealing will not prevent wear from abrasion.Used externally sealers will last between 1 & 2 Years before light cleaning and topping up.
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, gloves should be worn.
For detailed application instructions please see Technical Data Sheets.
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

How To Remove Orange/Pink Stains From The Edges Of Natural Limestone

Tanin and mould stains on Limestone copy

 

DEEP CLEAN UN-SEALED SURFACES TO REMOVE STAINS BEFORE SEALING

 

Limestone tiles are saturated with moisture during fabrication and packed into wooden crates for transport.  They are tightly packed so any retained moisture within the stone can remain for many weeks after packing. Moisture in the stone absorbs into the timber of the crate, which after a while causes tannins from the timber to become drawn into the edge of the stone, where it dries to leave an orange pink deposit. Retained moisture can also encourage the growth of mould spores which also contribute towards the staining affect.

PICTURE 1: SHOWS ORANGE STAINING FROM ALONG THE EDGE OF A PIECE OF WHITE LIMESTONE

Before copy

PICTURE 2: SHOWS APPLICATION OF MOULDEX TO THE EDGE AND SURFACE OF THE STONE

Mouldex application copy

PICTURE 3: SHOWS THE RESULT, PINK & MOULD STAINS HAVE BEEN REMOVED & THE STONE IS CLEAN

After copyBefore, during & After close up copy

STAIN REMOVAL:                         LTP MOULDEX                                                 500ML

Spray Mouldex to the edges and surface of the stone and spread out evenly making sure to cover the whole stone and not just the areas affected by staining. Leave on the surface for 2 – 3 hours. Agitate using a soft (white) emulsifying pad until the solution foams up and rinse well using plenty of water and a sponge. Change rinsing water after every 5 M². Surfaces should be left for a minimum of 24 hrs before sealing.

TDS – http://www.ltp-online.co.uk/images/tds-Mouldex.pdf

 

SEALING:                                        LTP MATTSTONE                                500ML,1&5ltr

Apply LTP Mattstone Sealer evenly to the surface of the stone using a sealant applicator pad. The impregnating sealer should be left for 45 minutes to absorb. Buff well using a soft cloth or machine with white pad to work off any visible excess.  Apply further coats at two hourly intervals using the same method. The object is to fully saturate the marble and terrazzo with sealer without allowing any excess to dry on the surface. The marble will be more absorbent than the terrazzo. Leave for a minimum of 24 hours before allowing traffic.  Treated surfaces will take about 3 days to become fully resistant. So light traffic only and do not wash.

TDS – http://www.ltp-online.co.uk/images/tds-Mattstone.pdf

IMPORTANT NOTES:
For really stubborn stains the stain removal process may need to be repeated.
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. Stone surfaces laid in heavily trafficked areas should be tested for moisture ingress every 12 – 18 months. If moisture absorbs apply more sealer.
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. Maintain sealed surfaces with PH Neutral cleaner LTP Waxwash.
For detailed application instructions please see Technical Data Sheets.
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

Why do I need to seal my Floor or Wall Tiles?

If your tiles are porous like Natural Stone, Terracotta, Slate, Polished Porcelain & Quarry Tiles then we would always 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

Impregnating Sealers:

Unsealed, most natural tiles are absorbent to some degree or other, just  pour a tea spoon

Natural stone protected with LTP Mattstone

Natural stone protected with LTP Mattstone

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.

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.

Surface sealers

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.

Apply LTP Glaze Protector

Glazed Tile- Sealed with LTP Glaze Protector

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.

And finally

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 ProtectorLTP 600ml Grout & Tile Protector Aerosol

Limestone: White or grey deposits on black paving?

Why do mineral stains show up so prolifically on black limestone pavers laid outside?

We are often contacted about mineral stains on black limestone paving. This is often perceived as an issue with the supplied paving stones, laying process or sealing method. Below we explained how a combination of naturally occurring elements can cause this phenomenon. It is in fact not uncommon and occurs with most types of limestone; however the appearance of mineral salt deposits on a black or darker coloured stone is more prevalent. This is why it is possible to notice some marks appearing even before sealing. As a naturally occurring chemical reaction it is often difficult to avoid. However, if fully understood and considered when laying and protecting black limestone this potential issue can be effectively managed.

What causes white and grey mineral stains on black limestone pavers?

When rain water trickles through mortar it can dissolve and transport soluble alkaline compounds. Rain water percolating through sand-cement mortar screed, toppings and bedding under limestone paving can become moderately alkaline. As this rainwater evaporates, its alkalinity increases until the solution becomes saturated. This solution can then travel via natural capillaries within the limestone to the surface where it starts to deposit solids such as white and grey encrustations of calcium carbonate commonly known as lime plumes and efflorescence as seen in the image of the black limestone pavers shown below.

Mineral deposit stains on black limstone

Halo stains and bands of mineral deposits

Trace amounts of sodium and potassium oxides within limestone can also be activated by rain water. Even where rain is mildly acidic, the solutions of these salts in rainwater will gradually become alkaline. Surface wetting and evaporation can produce recurrent patches and bands of dampness known as accumulation zones (rainwater pooling on the surface where it cannot run off). Evaporation concentrates the alkaline solutions until they become saturated at the outer limits or edge of accumulation zones. Further evaporation then causes precipitation, crystallisation and immobilisation of the salts at the surface and in pores immediately below the surface. The resulting bands of distinct pigmentation are halo stains as seen in the image of limestone pavers shown below.

Mineral deposits causing a banding effect

Reducing the impact

Protect your paving with the correct sealing product

Sealers used to enhance the appearance and prevent limestone pavers staining from organic matter outside should be breathable. LTP Mattstone, LTP Stone Oil and LTP Colour Intensifier are examples of breathable sealers suitable for external use. As well as protecting the stone from staining, breathable sealers will allow the microscopic transition of moisture assisting any trapped moisture to escape through the stone from the mortar and sub surfaces. However, moisture permeating through the stone and sealer to the surface can still dry to leave a calciferous deposit.

How do I remove mineral salt stains from the surface of limestone

Wash the surface with a mild solution of acid. This will help disperse the mineral salt deposits from the surface. The downside of this approach is that the acid solution can have a slight etching effect on the surface of the stone causing it to dry much lighter.

LTP Grout Stain Remover is a product suitable for this task. Dilute 1 part LTP Grout Stain remover in 4 parts warm water and apply to the surface of the stone. Agitate using an emulsifying pad or similar abrasive and then rinse thoroughly with plenty of clean water. Repeat this process to remove all mineral deposits.

Ensure you protect your paving by resealing

Once the surface is thoroughly dry and  mineral salt deposits on the surface are greatly reduced, re-seal the stone with an appropriate limestone sealer. LTP Mattstone is our most popular and highly effective natural stone sealing solution and is suitable for external use. However, many of our customers have successfully used LTP Stone Oil after acid washing their stone as it helps to re-enhance and deepen the colour.

Apply LTP Mattstone or Stone Oil impregnating sealer to the surface of the stone using a paint brush. Allow it to absorb into the stone and then remove any visible excess from the surface after 45 minutes using an absorbent dry towel. The aim is to completely saturate the stone with as many coats of sealer as necessary, but do not allow the sealer to dry and leave a film on the surface. Do not apply in direct sunlight.

Please note that this information is offered as general guidance only and without guarantee. Your specific circumstances may need an alternative approach. In case of doubt, any process should be tried out in an inconspicuous area before general application.

Resolving stain issues on natural stone can prove difficult. At LTP we believe in helping to offer solutions and this is why we offer a no obligation LTP TECHNICAL HELPLINE, so please give us a call on +44 (0) 1823 666213 and we will be happy to help you.

Alternatively visit our main site to view our full range of cleaning, sealing and maintenance products for all types of artificial and natural stone.