View Single Post
Unread 04-17-2008, 01:05 PM   #1
Registered User
Join Date: Apr 2008
Posts: 6
Need help with cracked tile and grout mystery

Hi there. I'm new here and very inexperienced with all of this, so please forgive me if I do something wrong. I am trying to discover the source of a problem with my kitchen tile. After a bit of research, here is what I came up with: We have about 400 sq. ft. of 12 inch porcelain tile in our kitchen and dining area. The home is four years old and was constructed with TJI Pro 130 Joists (2 5/16 wide by 11 7/8ths tall) 16 oc with 3/4" OSB on top. 1/2 inch Durock was then set in thinset and well screwed with the joints taped and covered with thinset. The thinset was mixed from a powder on site (not premixed).

After a couple of years, we began to notice a few of the tiles making a popping noise (not good) when stepped on. This only occurred during the humid summer. Eventually we began to notice cracked and crumbling grout in high traffic areas and hairline cracks in a few of the tiles.

We also have a master bath on the second floor with the same tile, set in the same thinset. It is perfect to this day (no cracks or grout problems). The only differences in the bath install were the brand of grout used and the installer. The kitchen grout was from Home Depot (not sure of the brand) and the bathroom grout was from Lowes (Mapei I believe). The kitchen tile was installed by my father-in-law. The bathroom tile by my husband. While he is no tile expert, my father-in-law is a general contractor and has installed thousands of sq. ft. of tile over the last 40 years (mostly in his own homes, with no problems over many years of use). My husband is most definitely a novice, but has done several small tile jobs.

Adding to my confusion, I dug the grout out around one of the problem tiles yesterday and easily popped it up (with a butter knife no less). There was almost no sign of thinset on the back of the tile and the thinset on the floor looked nearly undisturbed. I've only done the one tile so far, but I'm a bit worried that the tiles weren't pushed down into the thinset properly (which is hard to believe given my father-in-law's experience with tile). Of course I know next to nothing about tiling myself (except what I have learned reading this forum - thanks). Shouldn't there be a decent amount of thinset attached to the tile? I can't recall if the tiles in the kitchen were set the same day as the bathroom or not. It is very possible they were different batches of thinset, though the same brand.

We know the grout needs to be replaced and the cracked tiles. What I'm fearful of is that once we start digging out the grout, we will discover that most or all of the tiles are loose. Even if they are not, I'm afraid we will knock them loose trying to clean the old thinset off of the Durock.

So, my first concern is making sure that the joists and subfloor are adequate for the tile, and are not the cause of the problems. Any thoughts? If they are fine, then I am wondering if anyone has a guess as to the real cause of the cracks. I'm also open to suggestions on what to do. More and more I am realizing that we are probably looking at tearing it all out, but I'm not looking forward to explaining that to my husband (he was hoping to just regrout). Any suggestions on removing thinset from Durock without too much damage?

Basically, any advice you can give me would be amazingly helpful. Thanks in advance!

HA1311 is offline   Reply With Quote