How to fix cracks and missing grout in the shower?

[Josh86]

Hi, I’ve noticed a few cracks in my shower grout. Some are just hairline cracks in the grout at the base, while one section in the wall corner appears to be missing grout altogether. What’s the best way to fix this?

 

 

[Dave-1]

Afternoon @Josh86 

Mmm the question has gone past the level of my knowledge 😕 Tho I am interested as well about the depth and that dampness. I do think you would know if you had hit the waterproofing/concrete base as you would feel it with the scraper. I do know there are waterproof liquids you can cover the area with (soaks in and forms a barrier) but would wait for @JacobZ or @EricL suggestions. 

It does sound like you are in the level of screed more then teh tile glue. 

Dave

[JacobZ]

Hi @Josh86,

If it's on the first floor on a concrete slab, there's a pretty good chance it is screed. Screed is basically a bed of sand and cement that is used to create a fall towards the drain before laying tiles over the top. Screed is not waterproof, nor is it intended to be. There will be a Puddle Flange installed underneath the screed that will allow any water that gets into the screed bed to escape.

Waterproofing is usually done beneath the screed, so unless you keep going for another 40-50mm, you won't hit the waterproofing. 

I wouldn't worry too much. I'd just refill your grout lines as you had originally planned.

Let me know if you have any further questions.

Jacob

[Josh86]

Hey Jacob,

Thanks for explaining that. Makes sense now. I’ll just re-grout it like I planned. Appreciate the help!

Cheers,

Josh

[EricL]

Hello @Josh86 

Please keep us updated with your progress, we look forward to seeing your tiled floor regrouted.

Eric

[Nailbag]

If you have manage to go down in spots by 25mm @Josh86 it sounds like you have potentially broken through the waterproofing membrane as well which sits between the tile underlay/walk in shower mortar bed and the tile adhesive. And since it's a wet substance, this tells me that water has been making its way either through silicone or grout gaps.

Personally, I would hand the job over to a tile and re-grouting specialist. They will apply and epoxy grout then a clear waterproof coating over the showcase and up 1-2 tile rows. A certified service will over a decent warranty of workmanship and your insurance will cover any claim issues.

Nailbag

Nailbag 

[Josh86]

Hi @Nailbag 

Thanks for your advice so far.

Based on what I’ve found under the old grout (wet, crumbly sand in places 20–25 mm deep), do you think I need to start planning for a full shower renovation?

Or is there any chance it can be repaired properly without doing the whole base and membrane?

Keen to hear your thoughts.

Cheers,

Josh

[Nailbag]

Hi @Josh86 

Definitely don't need to start that level of repair at this stage. But I would get a couple of quotes from reputable regrouting and sealers.

Last year I discovered an almost same scenario as you with our ensuite shower being a walk-in. The wall on the other side was our bedhead and just by chance I looked under and noticed wet carpet and lower sections of the wall wet. This equals failed waterproofing on a 3 year old shower that was a fast track reno home we bought after COVID. So I started to remove a top layer of grout and edge silicone only to find most sections not even full depth, hollow and lots of water I could blow out with my workshop blower. 

I ended up removing it all, letting it dry out for about 6 weeks and then got a few quotes on repair. My 900mm x 1600mm shower and then up to tile rows on two sides ended up only costing about $600. I did have quotes over $1K. But I went with a local guy who I got a good gut feel for and great reviews.

Nailbag