Prep for Prep for Rigid Shower Trays

Aqua4ma Wet Room System

This is the ideal system for wet rooms and shower trays, the panels and trays are completely waterproof and rigid. And the solvent weld bonds the tongue and groove edges of the panels together very well. The solvent weld can also be used to flush joins between panels & cures within 30 minutes allowing you to sand it flat.

Rigid Shower Trays

You can also microcement onto any Shower Tray that is recommended for vinyl floors or microcement. These are rigid shower trays which allow for 3-4mm of product to finished floor height.

Here are the guidelines for completing the prep work for shower trays and the surrounding surfaces:

Well Consolidated & Completely Flat
Make sure the tray is well glued and screwed in place to eliminate any chance of movement. Countersink screw holes.

Around the Waste
Do a dry run with the waste so that you can see how it comes together, and check the levels, bearing in mind the microcement will only add 3-4mm to the surface of the tray. Ideally, you will have a clearly defined edge to work up to with your microcement – so no water can get underneath it. If not, you may need use some of the microcement base coat to flush it out &/or silicone the edge so that no water can get behind the microcement.

Around the Tray
If you are microcementing the floor outside of the shower tray, as well as the tray itself, the tray must be flush with the boards, ridges will highlight in the microcement surface. There must be no voids.

Microcement can’t be used to level surfaces/fill large voids. The microcement will follow the contours of the substrate it is going onto so make sure all surfaces are smooth.

Internal Corners (Between Wall & Floor/Tray)
There must be no voids between the wall & floor. If you are fitting the boards yourself, use an adhesive sealant along the bottom edge of the boards and squash the boards down to the tray/floor. Don’t smear silicone on the surface, instead, let it ooze out and razor scrape off the excess once it is dry. Use wide, self adhesive skrim tape to bridge the internal corner.

You have 2 options for achieving a flat surface & bridging the join between the tray and the other boards on the floor:

Option 1: Fill the Joins and Screw holes with Microcement Base Coat/Suitable Repair Mortar/Filler

This is the basic process – it relies on there being no movement at all in the sub-floor. Fill the joins and screw holes so that they are flush with the boards.

IMPORTANT: Leave until dry, minimum 24 hours. If it isn’t completely dry, the lines & holes may ghost through the microcement and be visible in the finish.

Once the Microcement Base Coat/Mortar/Filler is dry you can prime & mesh. For non-absorbent surfaces apply Primer TAC & for absorbent surfaces use Primer 100. Cut fibreglass mesh and lay it over the whole area, not overlapped, flip the mesh so it curls towards the floor and apply the primer over it with a medium pile roller. The primer will hold the mesh in place.

Option 2: Fill the Joins and Screw holes with Epoxy, Mesh & Sand Blind​

This is the more advanced process, which we highly recommend for joins in floors where there is more chance of movement when compared to solid surfaces.

Reduce the chance of movement transferring through to the surface by applying Epoxy, Mesh & Sand Blind over the entire floor. The epoxy will also fill the joins and screw holes to level off the floor. Use a trowel to apply an even coat of Epoxy over the sub-floor and mesh. You’ll need to ensure you have completely filled the joins and screw holes in the sub-floor and also completely covered the mesh, so that it has good adhesion with the floor.

Whilst the Epoxy is still wet, spread the quartz sand across the surface. You can scatter it by hand, starting at the entrance to the room and walking on the sand into the room. Or by walking on the Epoxy with spiked shoes. The following day, sand any high spots and hoover up all the loose sand.

You will need to prime the surface with Primer 100, you can apply a neat coat directly onto the sand. The Primer is applied with a medium pile roller.