How to grout a patio

When installing outdoor tiles, you need to prepare a solid concrete/cement substrate or choose a specific outdoor tile with an alternative fitting system.

When laying outdoor tiles on a solid concrete or cement substrate it’s recommended to use a flexible powdered tiling adhesive and a cementitious grout.

If all conditions have been met to use a cement-based grout, then we suggest using an efflorescence free grout such as BAL Micromax3 which can be used outdoors. Grout rated as "no efflorescence" ensures that the grout won't effloresce or lose moisture and develop a chalky white residue on the surface.

Before you start grouting it is important that you check for any potential staining risk. Even though it may seem like extra, unnecessary work, it prevents the paving stones or tiles from becoming stained by the mortar or grout.

Apply grout to a few tiles in a small trial area. If discolouration occurs or difficulties are encountered with cleaning off any surplus grout, apply BAL Protective Sealer and repeat the trial.

Using a suitable grout float, hold the grout float at a 45° angle and apply enough grout to completely fill the joints in a workable area, smooth the grout over the tile surface using diagonal strokes until the gap is completely filled. If a line appears in the grout you haven’t pushed enough grout into the joint to fully fill it, simply repeat the above process.

Remove any excess grout from the surface of the tiles with your float before moving on to the next area.

Once all the joints between the tiles/paving are grouted (working in small areas), allow approx. 15 minutes for the grout to dry (at 20°C) or when the surface of the grout is touch dry but not fully set.

Using a dampened sponge, clean the surface diagonally to the grout lines. Rinse your sponge frequently with clean water. Avoid putting too much pressure on the grout joints and don’t over wash them, if you do it will remove the pigment out of the grout’s surface and white areas will appear.

If you have over washed, this can be easily solved by gently sanding off the top layer of the grout with fine sandpaper once the grout is fully dry. Allow approx. 60 minutes for the grout to set sufficiently within the joints then polish the tile surface with dry clean cloth.

Provide protection against wet weather during grouting and for as long as possible afterwards. Too much water can cause the grout to cure incorrectly and eventually crumble or crack.

The following day, the face of the tiles will require a final wash down with Fila Porcelain Cement Residue Remover using cleanup pads to remove the polymers left behind by the grout. Failure to remove the polymers can leave a haze across the surface of the tiles/paving. Once dry, use a clean polishing cloth over the tiles until completely clean.

To pro-long the overall look and the actual life of your grout apply a coat of Fila's Grout Sealer. The spray is ideal for protecting wall and floor cementitious grout joints from dirt and general grime.

The nozzle enables an easy and safe application in an enclosed space wall. Spray it directly onto the grout joints, ideally in 1m2 sections,10-15cms from the surface, wipe off any excess and then allow to dry for 4-8 hours. The bottle only needs to be at a maximum 45˚ angle to point down, allowing maximum fluid extraction and excellent pump efficiency.

The Fila Grout Sealer is a solvent free grout protector and has high Eco values with no Volatile Organic Compounds. It’s completely solvent free and a water-based material offering a shelf life of 2 years.

A 500ml bottle will have a coverage of 20m2 based on a 10 x 10cm tile or over 300 linear meters regardless of tile size (based on a 5mm joint).

For more information on outdoor tiles, read our handy fixing guides.