Preparing Plasterboard Walls for Microcement

Watch the video below for a step by step guide to preparing plasterboards for microcement down to a shower tray and surrounding floor by Richie from Relentless Microcement.

The focus is on Bathrooms & Wet Rooms but the same prinicipals apply if you are using microcement on plasterboards elsewhere in the house too.

In this video, Richie demonstrates the most important things to be aware of when preparing surfaces for Microcement. Essential watching for anyone who is looking to Microcement plasterboard walls down to the floor.

Preparation is everything when it comes to microcement. The most important thing is that you have eliminated any chance of movement and your surfaces are completely flat.

Make sure your shower tray is well glued and screwed in place & there’s no movement in your floor.

First, put a bead of adhesive sealant along the edge of the floor & squash the plasterboard down onto it, allowing the adhesive to ooze out. Don’t try & remove the excess at this point, we’ll let it dry first.

Make sure your board is well glued & screwed in place so there’s no chance of movement. Making sure you countersink the screws.

Boards need to be nice & level with one another so there’s no lips. This is important because microcement is only 3-4mm finished & your trowel will highlight any imperfections in the substrate.

Any gaps in the substrate will need to be filled before you start so try to avoid them as much as possible.

Once all your boards are in place & your sealant has dried, razor scrape off the excess.

Next you’ll need to tape & flush the joins and screw holes. I’m using a filling compound for plaster boards. You can use you’re Microcement Base, for filling small voids but I find it does slump a bit on bigger ones. If you do use MicroDur Base, leave it for at least 24 hours until it is completely dry.

All substrates need to be completely dry with a moisture content of no more than 5% to take microcement.

Once your filler is dry, take some time to sand it back nice and flat. You don’t want any imperfections of more than around 3mm as this will show through to your finish.

And that’s it, you’ve eliminated movement and got a flat surface without any voids that water can behind. You’re ready to move onto priming and meshing your surface.