Mark Atkins, technical director at LTP discusses the best ways to maintain outdoor porcelain
Last year was another bumper year for porcelain – and this was very much reflected in our own technical enquiries.
Most related to issues surrounding residues and leaf stains. External porcelain’s still a relatively new surface, when you compare it to stone, and its popularity’s been driven by the introduction of fabulous new natural-effects. They create a really authentic look – and provide lots of practical features – but they bring with them their own set of gremlins.
A large proportion of issues relate to grout staining, be it white haze from cement-based products, dark staining for anthracite coloured grout or stubborn residue from resin-based formulations combining epoxy resin and filler. Issues are compounded by the fact that external porcelain is generally textured (to provide grip under foot), so residue tends to get trapped in the low surface areas.
Issues relating to leaf stains are also common. Leaves that fall onto pavers rot over time and release tannins – a natural substance that’s present in leaves, wood, bark, roots and fruit. The tannins create brown staining on the surface of the tile which is very hard to remove, even with jet washing.
Protecting a new installation from fixing stains
Matt porcelain doesn’t need to be sealed but, if you’re installing a new porcelain patio, a barrier treatment will protect the tiles and help prevent staining. We recommend LTP Porcelain Tile Protector. It provides a number of benefits: It prevents grout and resins from taking hold; it makes the removal of any residues much easier should they occur and it improves and increases grout working times. A further coat applied after installation also makes ongoing maintenance easier.
Before applying a barrier treatment, tiles should be cleaned and left to dry overnight. Our own protector can be applied with a paint brush or light pressure sprayer, with 30 minutes drying between the first and second coat. Once the treatment’s cured, after a minimum of an hour, tiles can be fixed. Any residue is then removed once the joint is dry and a further coat of protector can be applied to the tiles and joints.
Remove stains from an existing installation
If you need to remove resin stains from an existing porcelain patio, you can use LTP Solvex and heavy duty cleaner, Grimex. Solvex is a non-caustic intensive cleaner/stripper that helps to soften the resin residues, allowing for easier removal. It’s applied neat with a cloth or brush and left to act for 30 minutes; during this time more solution should be applied if it starts to dry out. The softened residue can then be removed with a coarse, stiff brush or a black emulsifying pad. If the staining is severe, the treatment should be repeated. The surface should then be washed down with a diluted solution of Grimex.
For cement-based grout haze and stains, LTP Cement, Grout & Salt Residue Remover can provide a solution. It can be used at different dilutions, depending on the severity of staining, and reacts within 15 minutes, after which the residue can be removed and the surface rinsed clean.
Porcelain is very robust but it’s not maintenance free. A good cleaning regime with a suitable detergent is important, to maintain a good appearance and slip resistance. If dirt’s allowed to build up in a textured surface, the tiles will become slippery and dull. The residue will then create a key onto which more dirt will stick and the surface will be more difficult to keep clean.
A blast with a jet wash may seem like the best cleaning option but overuse can cause damage and remove grout. A specialist cleaner will react with ingrained residue and organic matter, breaking it down for a more thorough clean. Tiles can be washed using a brush or garden broom and are then rinsed with clean water. For other stains, the range also includes Blackspot & Algae Remover and a Rust Stain Remover.
As a general rule of thumb, a porcelain patio will benefit from a thorough clean every couple of months or so – ideally, twice during the winter and three times during late spring and summer. Surfaces that are regularly cleaned will be far easier to keep clean. Regular cleaning of inside-to-outside surfaces, like those that run through bifold doors, will also help maintain a seamless aesthetic.