What might cause shower floor grout to crack?

sparklebreadApril 2, 2013

The shower floor was grouted in January. We began using the shower mid March. This morning I noticed this series of cracks in the floor. The cracks follow the tile for 18", originating from the wall and traveling the slope toward the drain.

I am thinking the cracks are a symptom. Any idea of what might be the cause?

Thank you for reporting this comment. Undo
geoffrey_b

Looks like the floor is flexing and it's telegraphing through the grout lines.

    Bookmark   April 2, 2013 at 1:46PM
Thank you for reporting this comment. Undo
sparklebread

Thank you Geoffrey. Is floor flexing normal on the second floor of a twenty five year old home? Is this a possible install issue? We are in the punch list phase of our reno- se we still have pretty frequent communication with our GC. I would like to have as much back up info as possible before I bring this to his attention.

    Bookmark   April 2, 2013 at 2:32PM
Thank you for reporting this comment. Undo
snookums2

Yes, tile being what it is, there are industry standards in place for preparing a good solid, sound substrate and how much deflection is acceptable in tiling installations in order to avoid situations like yours. Essentially, the floor should not be moving or the tile and/or grout will crack, further, allowing water to escape. Once the flooring person starts to lay that floor, he has taken ownership that it is a good foundation.

Now, whether anything else ever enters into it or there could be unforeseen conditions no one could know, someone else might be able to answer.

Do you know anything about the details of the install? Did you watch at all? Does the contract state any details or specs for how the job will be done. Say anything about "to be installed per industry standards, ANSI ASC ... "?

    Bookmark   April 2, 2013 at 5:20PM
Thank you for reporting this comment. Undo
sparklebread

Thank you snookums. I have complete faith in our contractor to do the right thing, not so much faith in the sub's tile setting skills as this is not, unfortunately our first issue with tile in the renovation. Problem is, the contractor tends to turm to the tile setter as the expert.

I tried to snap daily pictures, but some days other responsibilities got in the way. I am going to post what I have. If you don't mind telling me if the images give you any clues, I would appreciate it.

    Bookmark   April 2, 2013 at 7:01PM
Thank you for reporting this comment. Undo
sparklebread

pic 2

    Bookmark   April 2, 2013 at 7:02PM
Thank you for reporting this comment. Undo
sparklebread

edited- wrong pic posted. image removed

This post was edited by sparklebread on Tue, Apr 2, 13 at 19:06

    Bookmark   April 2, 2013 at 7:03PM
Thank you for reporting this comment. Undo
snookums2

I think there are some tiling experts who visit here but you can find in-depth assistance over at John Bridge which is a tile trade hangout with a help forum.

    Bookmark   April 2, 2013 at 7:14PM
Thank you for reporting this comment. Undo
geoffrey_b

"Is floor flexing normal on the second floor of a twenty five year old home? Is this a possible install issue?"

The felxing is called 'deflection'. All beams (floor joists) will have some deflection when weight is applied.

Tile being a ridgid material doesn't take well to flexing, and thus the tile cracks or the grout cracks.

The person who builds the shower should be aware of this issue, and how to prevent it.

For instance, maybe screwing down and additional layer of plywood would stiffen the shower floor, and lessen the deflection.

It looks to me like they will have to redo the shower floor.

    Bookmark   April 3, 2013 at 9:46AM
Thank you for reporting this comment. Undo
sparklebread

Geoffrey~ I was afraid it might be a tear out!

I did a GW and JB site search (thanks for the direction, snookums) and read about a test where you tap on the floor with your knuckle or plastic end of screw driver. If it sounds hollow then there might be underlying issues warranting a tear out.

Sounds hollow under the cracked area. Will report back for future reference.

Thank you!

    Bookmark   April 3, 2013 at 10:27AM
Thank you for reporting this comment. Undo
snookums2

So sorry to hear. It is heartbreaking and tiresome. What a mess.

    Bookmark   April 3, 2013 at 12:33PM
Sign Up to comment
More Discussions
Showers 101
I'm hoping there is someone who can direct me to a...
jpbenstock
Tile install question
I've been posting a lot about our upcoming master bath...
numbersjunkie
Bathroom
Walls are blue with red and royal blue towels white...
bobbyfly1
What is the strongest, best bathroom fan on the market?
We've had mildew in our old bathroom, despite having...
prairiemoon2 z6 MA
Quality Pocket Door Frames?
(Please accept my apology for the duplicate post -...
ahmnj
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™