How to Install Outdoor Slab Tiles Onto a Concrete Base

Looking to lay your own outdoor slab tiles? With the help of our resident DIY expert, Craig Phillips, we’re here to guide you on how to install outdoor slab tiles onto a concrete base.


Plan Your Layout

First, you need to decide how you’d like the layout of your outdoor slabs. This can be done in a few ways. Grab some paper and a pencil, and sketch out the general layout of the floor you’ll be laying your tiles. Sketch where you’d like your tiles to go and how you’d like for them to be organised. To plan carefully and accurately, begin by finding the centre point of your space. Measure the length of the floor and half the measurement, this distance will be your space. You can either place your first slab directly in the centre of this point or, lay a slab on either side of the point and work outwards this way. Do a dry run of your tiles with no adhesive before starting with the adhesive, to ensure your plan works for you and your space.


Planning layout of how outdoor slab tiles are going to lay on concrete base.


Mix your Adhesive

Before mixing your adhesive, ensure you put on appropriate PPE, this being a face mas and eye covers. We’re using Keraquick Rapid Set Adhesive, which is a flexible cement based powder adhesive, Mix this with cold, clean water in a large bucket with an electric drill and paddle mixer attachment.


Mixing adhesive to lay tiles on top of with drill and paddle mixer attachment.


Gently lower your first tile down onto the adhesive you’ve just laid down. Ensure you follow the layout of your plan from earlier on. Adjust your tile while the adhesive is still wet, ensuring it’s straight and level by using a spirit level. Use a rubber mallet to tap your slab into place, setting it into the adhesive. Continue laying your tiles in the layout you previously planned.


Lowering first outdoor slab tile onto adhesive.


Levelling System

As you lay your tiles, its worth considering using a levelling system throughout. They come with the base clip, which acts as a spacer to get an even joint across all your slabs, and a wedge, that gets attached to the clip and pushed through to level the entire surface of your tiles. You can order a starter kit that includes the base clips, the wedges and the tool needed to adjust the wedges, online from Tile Mountain.


Using levelling system to space the tiles and ensure the level is even across the outdoor slabs.


Once you’ve laid all of your slab tiles and used the levelling system to level them, you can remove the wedges from the clips and snap the clip away from the base which will now be set underneath your slabs.

Cut Piece Tiles

When you get the edge of your tiled area, you may find that you need to cut some of the slabs to fit into the space that you’re left with. If this is the case, there are a couple of ways of doing it.

First, measure the piece that you need to cut. Mark the distance onto the tile so you know where you’ll be cutting. We used a wet electric cutter with a diamond tip blade. These apply water to the blade as its cutting your tile to keep it nice and cool throughout the process. Alternatively, you can use a circular saw or nine inch grinder.

Cutting outdoor slab tiles with electric wet blade cutter.

Lay your cut pieces as you previously have with the rest of your tiles, including the levelling system. Continue checking your tiles are level throughout the process.

Laying cut tile pieces.


Sealing your Tiles

When you’ve finished laying all of your tiles, allow your adhesive to dry and prep the space for sealing. Use a brush to remove any dust or debris from the surface, If there are particularly tricky spots, use an old cloth with some clean water to scrub it away.


Wiping off debris with cloth to prep tiles for sealing.


We’d recommend using LTP Porcelain Tile Protector to seal your outdoor tiles for the best results. This can be applied using a paintbrush or a roller. Evenly spread this across the surface of your tiles, and leave to dry for about 30 minutes before applying a second coat.


rolling sealant over top of tiles to protect them before grouting.


Applying the Grout

To grout our slabs we used the Mapei Ultracolour Plus Grout. Apply your PPE and add a small amount of grout into a container. Mix with water by hand, using a trowel or something similar. Apply a small amount of your grout onto the tiles where your joints are. Use a rubber edge grouting float to push the wet grout into the joints, filling in all the gaps across your floor.


Pushing grout into tile joints with rubber grout float.


Wipe the surface down with clean water and a sponge, working in circular motions, removing any of the excess grout from the surface of your tiles. Repeat this a few times until your tiles are completely clean from leftover grout.

Tag us in images of your finished products on Instagram, @Tilemountainuk, we love seeing what you’ve been up to!


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