Share
Hi,
We are removing the grout from
our shower, which was installed as part of renovations about 8 years ago. The reason for this work is that thw original grout wasn’t drying out after showers (12 hours in between, sometimes days whent we went away) and in areas the grout was reducing to well below the height off the tiles. Our cleaning process has been to use a scrubbing brush on the tiles with a mixture of vinegar, dishwashing detergent and water which we spray on the glass and tiles.
To remove the grout, I have been using a grout saw and the multipurpose Ryobi tool from Bunnings - game changer.
I am now even more worried as there are black specs showing in the grout, sometimes with pinkish looking sections and of course, the grout which still hasn’t dried after two days of continuous industrial fan going in the bathroom. Last night, when i removed a section of grout, some water seeped into the grout from below. There isn’t any water damage under the floor - we checked under the house (Queenslander).
I would love any advice that can be provided on:
a) are the black specs mould (some of it has been below a layer if white grout) - we have since sprayed with mould killer
b) is the pink discolouration mould?
c) how do we dry out the grout so we can regrout?
d) how do I know when I am at the level of the waterproofing? - worried I will break it.
d) is this a bigger job than we imagined and do we need to be lifting all the tiles and then retiling.
e) what would have caused this?
Thanks in advance for any advice/help.
These are the black specks coming out of the grout
Welcome to the Bunnings Workshop community @BEALE. It's a pleasure to have you join us, and many thanks for your question about grout.
From what you’ve described, it sounds like the situation isn’t as serious as it seems. The black specks in your old grout are most likely just part of the original grout mix and are tiny aggregates, and the pinkish areas aren’t necessarily mould either. Grout is naturally porous, so it absorbs water, and it never truly dries out underneath tiles, which explains why it can feel damp even after a fan has been running. That said, removing any soft or crumbling grout and re-grouting is the right approach. You don’t need to completely dry out the area first, and there’s no need to lift tiles as long as the adhesive and waterproofing membrane underneath are intact.
When re-grouting, make sure to cut back the old grout a few millimetres below the tile surface, fill in properly, let it cure, and then apply a grout sealer. That will prevent water from penetrating and should resolve the issues you were noticing. Do not remove any more grout than what you have already, as you will hit the membrane, and the consequences of that are potentially having to remove all the tiles in your bathroom and reapplying the membrane, as membranes can not have patch repairs on damage.
If you want extra protection, epoxy grout is an option, but standard cement-based grout with a good sealer is usually sufficient. In short, this is a fairly standard repair job, and once re-grouted and sealed, your shower should be good to go.
Here's a helpful guide: How to grout tiles.
Please let me know if you have any questions.
Mitchell
