Should I Fit the Shower Tray / Tiles or Microcement First?

Trying to figure out whether to fit your flooring or shower tray before or after the microcement?  We’re here to help!

The guide below explains the process for each option so that you can decide which is right for you. This guide is focused on shower trays & tiled flooring but the same principles apply for any adjacent surface that will meet the microcement.

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There are a couple of ways to approach laying tiled floors or shower trays alongside an adjacent microcement wall.

Before the Shower Tray/Floor is Installed

This is our preferred method because it reduces reliance on the silicone join.

Prepare the Surfaces

Before starting the microcement application, ensure that both the walls and floor are well consolidated, movement has been eliminated and there are no voids in the substrate.  This is particularly important in shower areas & wet rooms.

See our Surface Prep Guides for more information on how to prepare surfaces correctly for microcement.

Install Microcement System

Once the prep is complete, you can then apply the full microcement system as directed in the online training.

When you come to the join between the wall & floor (or other adjacent surface), run your finger, or a corner trowel along internal corners to push the microcement into the corner and then gently trowel away the excess product in both directions, so that you have around 100mm lip of microcement on the floor.

Install the Shower Tray or Tiles

Once the microcement application is complete, you can install the tray or tiles up to the wall.

Silicone Along the Join

Once the tiles or shower tray is in place, apply a bead of silicone along the join where the 2 surfaces meet, to prevent any water getting behind any of the surfaces.

Silicone sealants must be 100% silicone to adhere to the microcement.

Pro Tip: Use a coloured silicone that matches the microcement for a more discreet seal. Mapei offer a good selection of 100% silicones that are available in a wide range of colours under the brand name Mapesil AC.

After the Shower Tray/Floor is Installed

If the shower tray or flooring are already installed, then you can still microcement up to it, but, because the join between the floor/tray & microcement coincide, the risk of water getting passed both surfaces is higher, making you more reliant on the silicone to prevent water getting behind any of the surfaces.

Cover Down the Shower Tray / Tiled Floor

Take care to protect the shower tray / tiled floor to avoid any microcement or other products damaging it.

Use a suitable tape to protect the surface, like masking tape, then apply gaffa tape on top.  The masking tape will protect the surface, and because it is stronger, the gaffa tape will peel back easier at the end of the installation.

This guide demonstrates the best tape configuration for Working Up to Thresholds & Other Surfaces.

Install Microcement System

Now you apply the full microcement system as directed in the online training.

When you come to the join between the wall & floor (or other adjacent surface), run your finger, or a corner trowel along internal corners to push the microcement into the corner and then remove any excess from the tape, to a thick build up of product along the join.

Remove the Tape

Once the microcement installation is complete. Remove the tape.  You may need a stanley knife to ensure you have a nice clean edge, right into the corner.

Silicone Along the Join

Apply a bead of silicone along the join where the 2 surfaces meet, to prevent any water getting behind any of the surfaces.

Silicone sealants must be 100% silicone to adhere to the microcement.

Pro Tip: Use a coloured silicone that matches the microcement for a more discreet seal. Mapei offer a good selection of 100% silicones that are available in a wide range of colours under the brand name Mapesil AC.