DO PORCELAIN PAVERS NEED TO BE SEALED?

Porcelain tiles are a great option for a patio installation.  They’re incredibly robust, resistant to most stains and are very easy to look after. But do they need to be sealed, like stone?

As a general rule of thumb, it’s only polished porcelain tiles that need to be sealed and these aren’t recommended for outdoor installation as they don’t provide any grip underfoot.  Porcelain pavers generally have a matt finish and a textured surface; outdoors, wood and stone-effect tiles are the most popular options. However, whilst matt porcelain doesn’t need to be sealed, it will benefit greatly from application of a ‘barrier’ treatment.  Tiles that have a textured surface can very easily become stained by grout and installation residues which become trapped in the tile’s high/low surfaces; it’s a particular issue in external applications, where brush-in jointing compounds are often used.  Once congested, the texture of the tile is lost along with the tile’s slip resistance. Ongoing maintenance will also be more difficult.

The benefits of a barrier treatment 

A quality, pre-grout water-based barrier, like LTP Porcelain Tile Protector, applied before grouting, will help protect tiles from staining and will make the removal of residues easier.  It will also make installation easier, as it will improve/increase grouting working times – and a final coat after installation will make ongoing maintenance easier.

How to apply LTP Porcelain Tile Protector

• Ensure that the surface to be treated is completely clean, dry and free from dirt, grime, cement and grout. If necessary, clean the tiles with a dilute solution of LTP Grimex 1:5, using a white pad. Rinse well to remove residues and let the tiles dry.

• Shake the bottle before use. Before grouting, apply evenly to the tile surface using a broad paint brush, foam roller or light pressure sprayer. Allow to dry for 30 minutes. 

• Apply a second coat. Leave to cure for a minimum of one hour before grouting or pointing. 

• Once grout/pointing is dry, and all residues have been removed, a further coat of protector can be applied covering the tile and joints.

For more advice on stone and tile protection and maintenance, contact LTP’s Technical Team on tel. 01823 666213, email info@ltp-online.co.uk or visit http://www.ltp-online.co.uk

HOW TO TREAT SLIPPERY PAVERS

Before treatment with LTP Black Spot & Algae Remover. Kindly supplied by Tom Barnard, Floor Restorer.

In periods of wet weather, paths and paving slabs can very quickly become slippery and potentially dangerous.  This can also be a problem year-round in areas that tend to be damp and get very little sunlight. Moist conditions cause slippery residue and algae to build up – and trying to solve the issue with more water can exacerbate the problem.  However, a thorough clean using the correct treatment will restore surface appearance, grip underfoot and help to reduce future build-up. 

This issue isn’t limited to any particular hard landscaped surface; it’s common on most, including natural stone pavers, porcelain pavers, concrete pavers, block paving, wood decking and composite decking.

Different types of algae

Algae comes in different forms and often creates a film or powdery deposit on pavers.  The term algae also includes cushion-like moss; Liverwort, which is a flat green growth with tiny leaf-like lobes, and Lichen, which is more crust-like and can also be yellow or orange. Jelly-like growths are also common; they’re often black or dark green and these are caused by a cyanobacteria called Nostoc.  None of these growths are hazardous – infact, lichen is particularly common in areas with clean air, so its appearance can be a positive sign – but slippery hard surfaces can be.

Another common problem is black spot – a speckle-like deposit that can be black or white.  Black spot is a dust-like lichen that originates from plants and trees. It colonises on pavers, sending tendrils or ‘hyphae’ down into any cracks or porosity, searching for nutrients. It takes about 2-3 years to become established below the surface and it creates a slippery residue on the surface of pavers. 

Addressing problem areas

Why water doesn’t work

A pressure washer and often a dose of household cleaner is a common go-to solution for slippery pavers.  However, excessive water only makes conditions even better for algae to flourish and pressure washing can damage the surface of the pavers, any sealer applied and it will loosen grout.  Water also won’t target hyphae or filaments anchored into place below the surface.   A specialist approach is necessary to effectively remove residue and microspores below the surface; any treatment used needs to break-down the slippery residue, to have a bleaching action to restore the colour of the paver and to target any growth below the surface. 

Care should be taken in selecting a suitable treatment.  If a solution is acidic, it will damage acid sensitive material and erode the grout joint.  We recommend LTP Black Spot & Algae Remover which can be safely used on all types of natural stone, concrete, brick and porcelain.  This treatment removes all types of organic residue, slippery matter and stains, breaking down hyphae below the surface, as well as preventing regrowth.  When applying the Remover, it’s also important to treat the whole area of paving, for a uniform appearance.   

Before treatment with LTP Black Spot & Algae Remover. Kindly supplied by Tom Barnard, Floor Restorer

After treatment with LTP Black Spot & Algae Remover. Kindly supplied by Tom Barnard, Floor Restorer

How to use LTP Black Spot & Algae Remover

Before washing pavers, any large, mossy deposits should be removed.  A long-handled block paving brush is a useful tool.  The whole area should then be swept clean to remove other residue, dirt and leaves.  

LTP Black Spot & Algae Remover should be applied neat to swept pavers, using a watering can or light pressure garden spray, where it fizzes during treatment.  It should be left to act for 2-4 hours and surfaces then hosed with clean water.  The solution can be used on dry and slightly damp surfaces and should be applied during a morning or afternoon of fair weather.  See a video aid on the product page.  Also, see LTP’s range of tools, including deck brushes and grout brushes.

After treatment, it’s worth protecting the surface; we recommend LTP External Stone Sealer for natural stone and barrier treatment, LTP Porcelain Tile Protector, for matt porcelain pavers.  Both will help prevent the absorption of moisture and organic particles, reducing staining and the spread of algae.

For more support and advice, browse the LTP blog, visit and subscribe to LTP TV on YouTube or contact the LTP team on tel. 01823 666213 or email info@ltp-online.co.uk