Assistance with cracking grout - Flexible grout? Adhesive tiles

Hi everyone,
So I decided to tile over a few layers of vinyl tiles in our old kitchen with new peel and stick 1x2 foot groutable tiles. I initially tried Homedepot's traffic master tiles, but within a day I noticed they were not sticking, so I peeled them up with my nails and returned them. Rona sold made in china, petroleum based peel and stick and boy, do they stick! In retrospect, I should've taken it down to the subfloor, but being an old house I knew there was a good chance I'd have to deal with asbestos tiles.

After doing the floor and grouting it with standard off the shelf Polyblend grout from home depot (Canada), within a few months of normal wear, I notice that the grout seems to separate from the curved tiles and sections of it start to crack and come out. I'm wondering whether there's any type of more flexible grout, as I assume the multiple layers and uneven flooring is causing this issue. Since it's a kitchen, something durable would help. I've now re-grouted twice within 2 years and it's no fun.

Any suggestions (other than ripping up the floor and going with hardwood like I initially wanted) would be greatly appreciated!

 

No idea. I don't like peel and stick because there is always a problem.

 

I think, as you also suspect, that the base under your tile is the culprit. You've probably got subtle movement as you walk across the floor that's breaking the grout joints. You might have better luck if you added additional additives to your grout mix but I'd give that less than a 50% chance of working long term. I'd consider grouting the joints with caulk. The same manufacturer of your grout has caulk in matching colors. It's not a perfect solution but the caulk, especially the silicone, is designed to accommodate movement.

 

Thanks Pilot and dane.

Specifically, what additives do you suggest? I was also searching around and came across epoxy based grout - what do you think of that - epoxy in my mind = strength, so would that be worth a try before I go caulking the floor? Won't caulking be rubbery - I know that's what will work, but won't that attract dust and dirt etc? I suppose it's better than cracked joints.

Anyhow, thanks!

 

Yes, silicone caulk would be rubbery. That's why it accommodates movement. So, you don't get something for nothing. It won't crack but it will be squishy like caulk and not hard like grout. There is also acrylic caulk that is more firm. It might be worth getting a tube of each. Squirt some out and let it harden and see what you think.

There are latex and other additives that can be mixed into mortar and grout in place of part of the water. They can help with strength and flexibility but they have their limits. If your floor is pretty solid it might be enough. If you really want to stick with a cement based grout I'd consider it but it's not a silver bullet. It might get you 10 or 20% more flexibility before cracking, but I just made those numbers up. It might get you more but I have no idea how much more or if it will be enough.

I have two part commercial epoxy grout on my outside porches. It's expensive but it is very good. It is extremely crack resistant but again I don't know if it will be enough. Then there is the philisophical problem. You've got peel and stick tile which is generally considered a less expensive material. Is a super expensive grout appropriate? At that point it might be better to go nuclear and rip everything out and do proper underlayment and traditional tile.

 

Thank you Pilot,
I was looking at either epoxy or urethane. I hear urethane is the 'new go-to' product. I suppose it'll leave it until the summer.
I don't want to rip it all out because 1) I'd be back to square 1 and 2) I've got a wife to contend with.

Shall see!