Tile grout crumbling

So I’m walking on an 8 year old tile bathroom floor, and it feels like I’m crushing the mortar underneath as I walk. There is deteriorated grout between the tiles on several areas. As never having laid tile before, what went wrong during the install? I can attach pix if you want, but I’m at the job now and haven’t uploaded them yet. Thanks

It appears that you’re walking on unlevel tiles. Probably improper backing…Simply have it evaluated and estimated for repairs.

Thanks David. I’m reaching on this one…very clean.

Could also be a very thin patch coat was used before laying the tile.

Thanks Rob. Regardless, for a water resistant membrane, I do not see it lasting much longer

From what you describe, they need to re-tile.(after they fix the problem underneath.

Bad tile job, too much deflection in subfloor, wrong or not enough adhesive, lots of variables


Tile appears to be installed*** inconsistent*** with any manufacturers specifications I have even read - ie - (Amateur Installation). Have a tile contractor repair is necessary

Welcome back Dale.:smiley:

How the heck are you?

I don’t think it totally necessary that you pinpoint the exact cause…which is most likely improper initial installation, I would just report loose ceramic tile on bathroom floor…

If I can jump in here… Is the crunching coming from under the tile? Or is it from the grout that has dried out and come out from between the tiles?

If it is the grout, then it was probably caused by to dry a mixture, or allowing the grout to dry out too much during installation. (I’ve had to patch a few areas of my own bath because I let the grout get to dry.)

If it is from underneath, or if the tiles are moving, then what everyone else has already said.

I agree, I am not looking to diagnose the problem for my clients sake, just mine. I’m telling the client to re-tile. I just like to know the why’s and how’s whenever I can. And on this board, there are plenty of them to be found.

It is both actually. Grout missing at the joints and crumbling underneath when walked upon. My instincts told me dry mix, but like mentioned before I never laid tile so there you go.

Hmmmm. Well, you don’t put grout under the tile, only between them. Mastic goes under, so that might be part of the problem.

Dylan having installed thousands and thousands of tile i can tell You there are a number of reasons you get what you saw today…number one reason…movement …could be improper sub floor installation…improper sub floor material…improper adhesive…wall tile installed as floor tile the list goes on…the major problem with ceramic floors in my opinion is improper preparation and amateur installation…if you have any more specific question i’d be happy to try to help…jim

That’ll do for today gentlemen. Thank you much. Once again, learned something new today. Everyday you should ask yourself, what have I learned or done for my business? Man, that sounded cheesy. :roll:

Hope you guys don’t mind I jump in to this one.

It appears from what was said that the interest is finding out what the cause was and not necessarily how to report it which would be as simple as saying needs repair.

Maybe I can shed some light as to the possible cause.

This is, by far, the most common use of ceramic tile, and if I’ve learned one thing over the years, it’s that every installation is unique in one way or another. Whether it’s the composition of the subfloor, the prep needed to ready the subfloor to receive the tile, the layout of the tile (or the room to BE tiled), or the design of the installation, something is always different.

Avoid using organic mastics adhesives to install ceramic tile to wood floors.

Avoid purchasing Fast Setting thinset mortars unless you are an experienced tile installer.

Almost any thinset mortar (Multi Purpose and polymer modified thinsets) will be adequate for installing most fired clay ceramic tiles on a cement substrate.

Fully vitrified porcelain tiles should be installed using a latex modified thinset or basic (non-modified) thinset mixed with an acrylic latex additive.

For installing ceramic tile over vinyl flooring or wooden substates you will need a high quality latex modified thinset mortar. These may be labeled as Full Flex, Super Flex, or Multi Flex thinset mortars.

A subfloor, in order to receive ceramic tile, cannot deflect more than 1/360

exterior grade plywood (CC plugged grade or better-- NO CDX-- too many voids)

Installing ceramic tile on OSB should be prevented, This product will obsorb the moisture out of the thin set mortar too fast and loose it’s adhesion.

Plywood substrates are better, but recommend using a modified latex product along with an acrylic latex addittive for a better bond adhesion.

Chances are if the crumbling sound occurrs, it has lost the adhesion to the substrate.

The flooring will need to be removed and redone.

Hope this helps.

Marcel :):smiley:

DALE DUFFY!! You get back in bed! :stuck_out_tongue:

Hope you’re good and gettin’ better. :smiley:

I’ll second that !!!