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.


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. 

Crackle Glaze Tiles & water marks

We were recently contacted by a customer who had concerns about her crackle glaze tiles that were installed in a shower area & sealed with LTP Crackle Glaze Sealer.

After using the shower small dark spots appeared. See images below.

Crackle glaze blog photos (1) with arrows Crackle glaze blog photos (2) with arrows









When newly laid crackle glaze tiles are fitted they will expand and contract with the change in temperature, especially in a wet room. This causes new cracks to form in the glaze, this new crack will be slightly porous and this will continue probably for about 6 months until the tiles have fully settled.

The customers concerns are as follows our answers in blue.

Q. Can mould grow as water can penetrate the tiles?

A. As far as we can gather from the information provided the dark marks that appear are drying out between wetting so the retention of moisture is relatively low. If ventilation in the bathroom is adequate, then we would not expect mould growth to be an issue. Cleaning the tiles with LTP Stonewash on a regular basis will help keep the surface clean without compromising the protection.

Q.Is the Crackle Glaze Protector adequate on its own? Why do you recommend the use of LTP Tile & Grout Protector Aerosol?

A. Crackle Glaze Protector contains a nano polymer that helps bridge the gaps between the crackles in the glaze. Filling these micro voids helps to ensure that stains and residual grout do not fill the cracks in the glaze, potentially altering the original character of the tile. Despite being an effective stain blocker the sealer does also need to remain breathable. This ensures that microscopic transition of moisture can still take place, even after the sealer has fully cured.  If moisture gets behind the tile then it should till dry out.  If moisture passes through a newly exposed crackle in the glaze due to settling then it should also still dry out.

Some customers prefer the convenience of topping the protection using the grout & tile protector because it is quicker and easier.  The polymer used in the grout & tile protector is slightly larger, so we would not normally suggest it is used as a primary sealer in place of the Crackle Glaze Protector on crackle glazed tiles

Q. Are tiles that have a water absorption rate of greater than 10% considered suitable for bathrooms?

A. Provided that the crackle glazed tiles are set into a flat even bed of adhesive with full contact to the reverse side of the tile without any voids, followed by a sufficient seal, then there should not be any great issues with water absorbsion/retention. We have seen on a  number of occasions installations where tiles have not been set into sufficient bed of adhesive allowing for voids between the all and the reverse side of the tile.  In wet areas such as shower enclosures moisture and condensation can build up behind the tiles and dwell within the open voids.  If the tile used has a relatively absorbent biscuit, then this moisture can travel from the reverse side of tile through to the face leaving a water mark that can take a longer time to dry out.


Crackle glaze tiles that have been sealed.


It is also recommended to seal before grouting or cutting the tiles, as grout can also enter these small cracks and become almost impossible to remove. There are different methods for sealing dependent on what colour grout is being used.

Crackle glaze 2 copy

Crackle glaze 3 copy


For regular cleaning the of the tiles we recommend using LTP stonewash, this will help keep surfaces clean without compromising the protection.



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.

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

Patio & Driveway Surfaces – Cleaning, Sealing & Maintenance

Natural Stone Surfaces – External Application

Cleaning, Sealing and Maintaining Natural Stone – Part Three

Natural stone has been used as an external surface covering for paths, driveways, patios, court yards, terraces, porch areas,verandas, loggia and sun decks for centuries. As with all natural materials, it does need a certain level of care.

This is the third in a 16 part series of posts that will offer a comprehensive guide to cleaning, sealing and maintaining all types of stone, porcelain, quarry, terracotta and glazed ceramic tiles and surfaces. This post explains the LTP three-step approach to cleaning, protecting and maintaining natural stone surfaces used in external applications such as paths, driveways, patios, court yards, terraces, porch areas,verandas, loggia and sun decks. Natural riven or rough cut stones are often used outside because they are naturally slip resistant. Normally thicker than internally fixed stone they are more robust and harder wearing. The following guide will explain the process and help keep your surfaces maintained and in good condition for many years.

Natural Stone Surfaces – External Application

The following instructions are for sawn and honed, riven or rough cut finish: sandstone, slate, granite, quartzite and rough cut and riven limestone.

Step one: Initial cleaning

Before sealing, clean natural stone thoroughly to make sure that the surface is sealed  effectively. This is true of newly installed surfaces, as well as existing, due to the contamination that can occur during fitting. On existing surfaces such as patios, driveways, paths and terraces remove old layers of sealer, dirt residues and light deposits of organic matter and algae  from the surface and pores of the stone. For newly installed surfaces cleaning should remove all grout and cement residue and any general dirt or grime that has built up while fitting. Bucket, mop, sponge, scrubbing-brush or scrubber dryer machine if available.

Newly installed surfaces

Before grouting and once surfaces are clean and dry: Apply one coat of LTP Colour Intensifier & Stainblock before grouting. This treatment will help with the removal of residual cement and grout from the surface of the stone paths, driveways, patios, court yards, terraces, porch areas, verandas, loggia and sun decksLTP recommends using LTP Grout Stain Remover to clean and remove residual grout and mortar from the textured riven surface of natural stone driveways, patios, court yards, paths, stone terraces,verandas, porch areas and sun decks once they have been laid.

Please note: Do not use LTP Grout Stain Remover on honed and smooth limestone. 
This product is only suitable for use on riven limestone.

Cleaning newly installed reclaimed flagstones, rough cut, honed and tumbled stone surfaces

  1. Dilute LTP Grout Stain Remover 1:2 with water. On rough cut limestone dilute 1:6
  2. Apply solution to the surface with a stiff brush and agitate immediately.
  3. Leave for 5 minutes and agitate again. Rinse well with water.
  4. Rinse well with plenty of clean water.
  5. Allow the surface to dry.

Step One Cleaning External Stone Surfaces

Refurbishing used and heavily soiled stone surfaces

  1. Before sealing the clean stone thoroughly. 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.
  2. Dilute LTP Grimex 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.
  3. Agitate the surface with a stiff deck brush every 5-10 minutes (scrubber machines can be used).
  4. Continue to scrub while adding clean water. Remove residues from the surface with water or scrubber machine.
  5. Rinse thoroughly with clean fresh water to remove all remaining residues. Use a power washer if necessary.
  6. Allow the surface a minimum of 3 dry and damp free days before applying the protective seal.
  7. For the removal of other types of dirt refer to the table below.
  8. Do not allow the sealer to dry on the surface. Carefully buff with a soft cloth or machine to remove any excess. Complete this within 1 hour of application.

For the removal of other types of dirt refer to the list below. If you are unsure please call our helpline for advice.

Step two: Protect your natural stone surface from stains

To protects sawn and honed, riven or rough cut finish: sandstone, slate, granite, quartzite and rough cut and riven limestone surfaces and help prevent staining LTP recommends the application of LTP Colour Intensifier & Stainblock.

The equipment you will need for this task: bucket, applicator, brush, cloth.

Application of LTP Colour Intensifier Stainblock: Enhanced natural finish protects against water, oil, grease, dirt, grime, organic matter and aids maintenance

  1. Clean surfaces and ensure they are dry.
  2. Apply the product to the surface evenly using a sponge, brush or soft cloth.
  3. Redistribute to remove excess product and avoid pooling on the surface.
  4. Allow to dry. Do not walk on the surface for at least 3 hours.
  5. Protect from damp and wet conditions for at least 3 days.

Step 2: Sealing external stone surfaces

Step three: Maintaining your reclaimed flagstones, rough cut, honed and tumbled stone surfaces

Using the correct maintenance product will increase the life of your stone seal, provide more protection against staining and make sure your path, driveway, patio, court-yard, terrace, porch area, veranda, loggia or sun deck looks great. Common household cleaning products often contain harsh substances that can breakdown sealing products applied to stone. For this reason LTP recommends using LTP Grimex on external surfaces sealed with LTP Colour Intensifier & Stainblock. LTP Grimex will remove surface dirt when required (normally every 3-6 months).

Regular maintenance on sawn and honed, riven or rough cut finish: sandstone, slate, granite, quartzite and rough cut and riven limestone

  1. Dilute LTP Grimex 1:3 with water.
  2. Apply the solution to the surface and agitate.
  3. Leave for 10 minutes before agitating again and then rinse with water.
  4. Leave to dry for 24 hours and then if necessary re-apply a light coat of sealer.
  5. Protect from damp and wet conditions for a minimum of 3 days.

Step 3: Maintaining External Stone Surface.

Should you use a professional floor restoration company?

The application techniques described above are achievable by a competent DIY enthusiast using the products as described. However, natural stone products are often expensive and by nature each stone has its own characteristics. We often find that many of our customers prefer to use the experience and skills of a professional stone restoration and cleaning company to make sure that their project is completed to the highest standard. LTP is pleased to associate with the following companies that specialise in natural stone restoration and cleaning:

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
, so please give us a call on +44 (0) 1823 666213 and we will be happy to help you.

Visit to buy from the LTP Range of products or find out more about us.


Grout care – cleaning and maintenance

How to get grout clean? – Top tips

Mould & Mildew on groutWhy does grout discolour and become dirty?

Most grout used in domestic situations such as bathrooms and kitchens is water-resistant and not water proof. This means that while your tiles may repel moisture your grout can often absorb it. When mopping dirt off the surface of tiles it is the moisture carrying dirt particles that absorbs into the grout causing it to discolour. In wet areas such as showers or wet rooms it is possible to get a build up of soaps, moisture and sebum within grouting. If not cleaned properly this will stay within the grout and encourage mould spores and mildew to grow.

Approaches to cleaning grout

Cleaning groutThere are many ways that people choose to tackle issues of mould growth, mildew and dirty grout between wall, floor and surface tiles. Household chlorine based bleach; baking soda and vinegar are three common approaches. While these methods can prove effective for cleaning glazed ceramic tiles, there are a number of issues that can make them inappropriate for use with natural stone and tiles. General-purpose chlorine bleach cleaners can damage the stone or the protective sealer applied to the surface. Do not use products that contain lemon, vinegar or other acids on acid-sensitive stones such as limestone, marble and terrazzo as these may etch the stone surface and damage the polish or sealer. Do not use scouring powders or creams; these products contain abrasives that may scratch the surface. This can also apply to glazed tiles. Hydrogen peroxide cleaners can also be mildly corrosive. They give short-term cleaning benefits with limited effectiveness on fungal spores, making them poor at preventing re contamination. Baking soda is a great option with fewer disadvantages. However it can often prove ineffective in tackling stubborn stains and often requires excessive scrubbing to deliver results. In all cases the use of highly abrasive cleaning tools such as wire wool should be avoided, as these will scratch the surface. Ensure you use an appropriate abrasive cleaning pad designed for natural stone.

LTP Tips for cleaning grout between tiles

LTP has been producing natural stone cleaning sealing and maintenance products for over 25 years. Our goal is to produce highly effective solutions design specifically for natural stone and ceramic tiles. To clean dirty grouting on floors and walls we recommend the use of LTP Grimex.

LTP GrimexLTP Grimex

An intensive grease and grime cleaner suitable for intensive cleaning of grout between glazed ceramic or porcelain tiles or unglazed natural stone. LTP Grimex is also excellent for renovating old quarry tiles, terracotta, slate, stone, marble and stone fireplaces.

For further information or to buy LTP Grimex >>

Please note: LTP Grimex will not damage natural stone surfaces if used correctly. It does however breakdown protective layers of sealer and waxes on the surface. It is therefore recommended that the product be tested on a small inconspicuous area before general application. Natural stone tiles should also be resealed after use. Glazed porcelain and ceramic tiles are not affected. Please contact our technical helpline for further advice and assistance.

LTP grout cleaning tips for mould growth and mildew

Grout is porous and absorbs water, especially in humid places like the bathroom. As a result, fungi such as mildew can often be found growing between tiles, in the grout. Removing unsightly mould growth and mildew stains can prove a difficult challenge. The LTP Research & Development Team has developed a unique solution to this problem called LTP Mouldex.

LTP MouldexLTP Mouldex

Formulated to cling to grout and remove mould spores, fungus, algae and moss from grouting, silicone seals and other damp places. LTP Mouldex has antibacterial properties that help to prevent re-growth. LTP Mouldex a 500ml trigger spray ideal for use on bathroom and kitchen wall tiles but can also be used to tackle small areas of floor grout.

For further information or to buy LTP Mouldex >>

When Grout Cleaning Tips Don’t Work

If all your grout cleaning attempts fail, it is time to remove the grout. This doesn’t automatically mean redoing the entire grouted area. If the stain only affects a small area, try removing just the small section affected by the mould growth or stain. For a shallow stain, use a hand-held rotary tool or mini sander to remove just the top layer of the grout. Take care not to damage your tiles. Re-seal the grout to give future protection. A deeper stain means more of the material will need removing. Removing such a stain may need a fresh coat of grout altogether.

The most important tip of all – Protect your grout!

Whether tackling mould growth, mildew, stubborn stains or ingrained grime, grout cleaning is not the most pleasant housekeeping job to perform. Most people avoid it as long as possible, which exacerbates the problem.

So the very best tip we can give is to make sure that you protect you grout and stone surfaces when they are installed and after intensive cleaning. Maintain your tile and stone surfaces regularly. Always make sure that you top up the protection to your grout after cleaning.

LTP Grout Protection

LTP offer two grout protection options:

LTP Grout Protector 1LLTP Grout Protector – 1L 

Recommend for sealing newly laid grout. LTP Grout Protector is a colourless barrier suitable for use in kitchens and bathrooms. Helps protect absorbent, porous grout joints from water, dirt, oil, grease, sebum and limescale. Ideal for use on newly laid glazed ceramic wall and floor tiles where in normal conditions unprotected grout joints quickly become dirty. This product is also ideal for sealing grout between natural stone tiles that have been sealed prior to being laid.

For further information or to buy LTP Grout Protector – 1L >>

LTP Grout & Tile ProtectorLTP Grout & Tile Protector
– 600ml Aerosol Spray

This product is an easy use as a top-up coat. Helps protect natural stone and all other types of masonry surface. Provides a colourless barrier that helps to protect porous wall and floor grout joints from penetration by water, dirt, oil, grease and limescale. Treated surfaces are easier to keep clean and repel dirt and grime. Ideal for use in wet rooms and shower enclosures as a top up protection for grout after intensive cleaning.

For further information or to buy LTP Grout & Tile Protector >>

At LTP we believe in helping to provide 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. Visit to buy from the LTP Range of products or find out more about us.

Should I protect polished porcelain from staining?

Polished Porcelain Tiles – Are they maintenance free?

LTP recommends that you protect polished porcelain when fitting by applying an impregnating sealer to ensure the best resistance to staining. It is also important to make sure that polished porcelain is regularly maintained to make sure that stain resistance is maintained.

At LTP we receive several calls a week about polished porcelain which is often sold as a maintenance free alternative to stone, marble or granite. This is not necessarily true.

Regardless of the information that factories offer on this subject, in our experience, 90% of polished porcelain tiles require sealing for one simple reason. The mechanical polishing process used to finish polished porcelain opens up the pores on the surface of the tile. This can lead to maintenance problems and in our view prevention is better than cure so we always advise customers to seal and protect polished porcelain.

Test your polished porcelain to make sure it is protected

LTP MPG Sealer, 5 & 1 Litre & 500ml

LTP MPG Sealer is an impregnating sealer ideal for polished porcelain.

To avoid any doubt you should test an inconspicuous area of your polished porcelain tile. Take a tile and pour on some red wine or cooking oil or even mark the tile with a pen. If after a couple of hours you can remove all three then the tile is fine, if not we recommend the tile is sealed with
LTP MPG Sealer to protect the tile without altering the polished surface.


Protect polished porcelain

Some polished porcelain tiles are pre sealed at the factory. This sealing process tends to leave the surface of the porcelain tile smeary and the tile is still vulnerable to staining.

Application of LTP MPG Sealer is quick and easy

The first step is to wash the tile with LTP Grimex or LTP Power Stripper, which removes the original seal. Ensure the surface is dry and that under floor heating is turned off. Then apply a light coat of LTP MPG Sealer to the surface of the tile using a cloth or paint brush and after about 20 minutes use a soft cloth to buff any excess sealer. The buffing is an important part of the sealing process as it encourages the sealer to penetrate all the pores of the porcelain tile and removes any excess sealer from the surface. Leave to dry for two to three hours and re-try the wine, oil and pen tests. Unlike other wax/silicone-based sealers, LTP MPG Sealer is an impregnating sealer so it does not sit on the surface of the tile. Protect the sealed surface from water for 24 hours and do not wash surfaces for at least 3 days.

If LTP MPG Sealer is over applied and the surface of the tile has gone smeary, then re apply a little more sealer and buff off the excess.

For further information on sealing polished porcelain please download our polished porcelain application guide, (PDF format).

Removing stains from protected polished porcelain

Some stains such as marker pen might penetrate the surface of the porcelain tile. It will not however stain the tile as the LTP MPG Sealer below the surface will have absorbed the stain. To remove just apply a little white spirit or LTP Grout Stain Remover. This removes the sealer and the stain with it. To re seal just apply another coat of LTP MPG Sealer to the porcelain tile or area and rebuff.

Protect polished porcelain before fitting

As most stains occur during the fixing stage, we suggest that polished porcelain tiles are pre sealed, especially before grouting as many types of grout, especially dark colours will leave ‘tide mark’ stains along the grout joints. Once the floor is fixed and cleaned off it makes sense to apply a second coat of the sealer to protect polished porcelain fully against household stains.

Maintenance is vital

To protect polished porcelain fully there is last point to remember. The use of the incorrect cleaning product will remove the seal from the porcelain tile and cause the tiles to stain. Clean floors sealed with LTP MPG Sealer with LTP Waxwash.

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 polished porcelain 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 the main LTP site to view our full range of cleaning, sealing and maintenance products for all types of artificial and natural stone.