How to regrout shower floor?

Question

The grout on the shower floor is old and brown and missing in places.  I've tried removing some with the removal tool, but it's like cement.  It's very hard.  I've cleaned the floor and waited a couple hours to air dry.  I've tried using pre-mixed grout.  I've mixed it and applied it to the floor and used grout tool at 45 deg to the tiles.  I waited 1/2 an hour to wipe off excess with a damp sponge.  Everything looks good.  Waited 24 hours and the grout is powdery when I run my finger over it and it just washes away when I use the shower.  This has happened twice now.  IS the floor too wet to begin with?  Am I not witing enough for it to completely set?  I can't not shower for several days.

MitchellMc · Answer

Hi Ant2026,

Thanks for confirming you’re using Davco Easy Grout. In wet areas like showers, it can take up to 72 hours before it’s ready for water exposure. In humid Brisbane conditions, drying can take even longer, which is likely why it’s washing out.

If you can’t avoid using the shower, you could try regrouting in small sections so part of the floor stays usable, and use fans and ventilation to help it dry faster. I've confirmed with Davco that due to the humidity, there's no real way to reduce curing times.

Mitchell

Ant2026 · Answer

I'm using Davco Easy Grout (pre-mixed and ready to use).  So, I can't use the shower for 3 days?  There must be a faster way to do this.  This is the only shower I have and no bath.  I not going 3 days with out a shower.  This is Brisbane and it muggy today.

MitchellMc · Answer

Welcome to the Bunnings Workshop community @Ant2026. It's wonderful to have you join us and many thanks for your question on grouting.

Would you be able to let us know which grout product you’re using? That will help our members provide more informed advice specific to the product.

From what you’ve described, a couple of things could be contributing. Powdery or weak grout can sometimes happen if too much water is used during clean-up. When wiping off excess grout, make sure the sponge is only damp, not wet, and rinse it frequently while wringing it out thoroughly each time.

Remove the initial excess grout around 15 minutes after application. Then do the main clean up once the grout has firmed up more, usually around the 1-hour mark, depending on the product and temperature.

Also, most cement-based grouts can take up to 72 hours to properly cure. Unfortunately, the shower should not be used during this curing period, as exposure to water too soon can cause the grout to break down or wash out.

Please let me know if you have any questions.

Mitchell