Grout care: cleaning and maintenance

By Mark Atkins, Director, LTP

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
There are many ways 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 as 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.  Always use an appropriate abrasive cleaning pad designed for natural stone.

Tips for cleaning grout between tiles
LTP has been producing natural stone cleaning sealing and maintenance products for over 25 years.  The company’s goal is to produce highly effective solutions designed specifically for natural stone and ceramic tiles.

To clean dirty grouting on floors and walls LTP recommends the use of LTP Grimex.

LTP Grimex
LTP Grimex is 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.

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.

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 solution to this problem called LTP Mouldex.

LTP Mouldex
LTP Mouldex is 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, is ideal for use on bathroom and kitchen wall tiles but can also be used to tackle small areas of floor grout.

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.

Most important: 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 LTP provides to its customers is to make sure that grout and stone surfaces are protected when they are installed and after intensive cleaning.
LTP advises customers to maintain tile and stone surfaces regularly, and to always top up grout protection after cleaning.

LTP grout protection options
LTP offers two grout protection options.  LTP Grout Protector, which comes in 1ltr bottles, is recommend for sealing newly laid grout.  LTP Grout Protector is a colourless barrier suitable for use in kitchens and bathrooms.  It helps protect absorbent, porous grout joints from water, dirt, oil, grease, sebum and limescale.

LTP Grout Protector is 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.

LTP Grout & Tile Protector, which comes as a 600ml aerosol spray, is easy to use as a top-up coat.  It helps protect natural stone and all other types of masonry surface.  It provides a colourless barrier that helps to protect porous wall and floor grout joints from penetration by water, dirt, oil, grease and limescale.  Surfaces treated with LTP Grout & Tile Protector are easier to keep clean and repel dirt and grime.  It is ideal for use in wet rooms and shower enclosures as a top up protection for grout after intensive cleaning.

The no obligation LTP Technical Helpline is available on 01823 666213.  Visit to buy from the LTP Range of products or find out more about the company.