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Hairline crack in shower floor grout. Should I care?

52K views 11 replies 4 participants last post by  ccarlisle 
#1 ·
Hello
I just noticed a hairline crack in a grout line on my shower floor. My shower is only 2 years old. However, the house was a short sale and the builder "disappeared" so I don't know the construction methods used.

My questions are:
1. Should I care enough about this crack to repair it by removing the 3 inches of old grout and putting in new grout? From my research I have learned that grout does not prevent water from seeping down and that the water proofing system under the tile actually does the job of keeping the wood underneath dry. (Since I don't know the construction methods I am in the dark on this)

2. About a year ago I noticed that the grout in the wall/floor seams was what I would consider lacking. I decided to put caulking around the seams to help protect from the water. Now the caulk is disgusting and turning while. It was clear. I want to replace the caulk but want to make sure that it is ok to put caulk over grout in the corners.

Here are some pics. The first one is the crack and the second is just to give you an idea of the tile size.



 
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#2 ·
Hi,

Yes you should repair the cracked grout. While tile and grout do not make the shower floor waterproof, the cracks allow much more shower water into the system.

I'll bet the base was not built with the required sloped membrane which would allow any moisture to escape thru the weep holes. Building shower pans wrong is very common. This may be an indication since you're also having problems at the floor/wall junction.

I don't think caulk over grout is a good practice, just fast. I think you meant to write it's turning white, this could be efflorescence, another indication that the deck mud is saturated. The next step is it'll turn brown or black.

Jaz
 
#3 ·
Hi,

As far as point 1. is concerned. Yes you should repair the grout as water will always find a way through if the grout on a wet area floor is cracked. You can easily repair it by purchasing a grout rake from any tile shop. Chopping the grout out and replacing it. It should be no more than a 15 minute job. If the shower is on a suspended or timber floor, it would make sense to put some flexible additive in the grout.

As far as point 2 is concerned, Its not generally a good idea to put caulk (or silicone) over grout as it discolours. I would spend a little time on it, cut as much of the caulk as you can out with a box cutter and remove any residue with silicone sealer remover . Then use your trusty grout rake to cut the grout out of the corners. Once you have done this use your caulk ( I would recommend Dow Corning 785) to fill the gaps where the grout was. I know that caulking can be difficult to get neat so just do a little at a time unless your'e used to it. This should provide a more permanent solution. Finally, remember it is ESSENTIAL to let the silicone dry fully before using the shower.

Hope this is of some help.

Regards,

Martin
 
#6 ·
Thanks for the reply. This seems to get more complicated by the post.

I spent hours last night cutting out the caulking from edges. Portions of the caulk had let water underneath and allowed mold to grow. Good thing I ripped it out. I went through 8 razor blades trying to get it all out.

The situation is more dire than I originally thought. More pictures are included. I found a cracked tile and the grout at the edges is basically failing now.

I'm wondering if I should replace the entire floor at this point? I get the feeling that problems are going to continue to pop up plus I hate the tiles that are on the floor now.







 
#7 ·
Since you're having these problems and you hate the tiles anyway, go ahead and remove the tiles and probably to concrete base under it. Be very careful not to damage the shower membrane under the concrete though. First familiarize yourself how a shower is built using the "old" method as yours most likely is. http://picasaweb.google.com/jazcastiglione/ShowerDeckOldMethod#5318267724695542178

You'll then mix the new deck mud, (get back on that when ready), make the proper slope then set the new tiles the next day. Be aware this will not cure all the mistakes I suspect, (no pre-slope for one), it'll be an improvement.

There's much more to know, but decide if you're gona rip it out first.

Jaz
 
#8 ·
Update:
I just removed the grout that was cracked. I was vacuuming out the grout particles when I noticed that I was pulling small amounts of water from under the tiles with the vac.

I just found out that I have travertine tiles. I was told that water will seep through the tiles and the grout since neither are water proof.

Question: Should I be concerned that I am pulling water out of the crack? The crack is new to the wall and about 12-14 inches from the drain. The shower has not been used for 24 hours and has had a heater in it all night.

My plan was to remove the old grout and then re grout but now I am concerned that I will need to go farther.
 
#9 ·
Do not grout now. There is about 2" of concrete under the tiles, this concrete is saturated with water. It will take months for the concrete to dry if left alone. You have confirmed my suspicions that your shower is not built right, typical but not right.

You can let it dry, grout it, then have the same situation again and again or take more drastic corrections.

Those tiles looked like travertine, but those few dark tiles made me think it may have been something else. Yea, that wasn't such a great choice either.

Jaz
 
#10 ·
what a nightmare.

OK, I removed two tiles next to the grout crack. The thin set held good, I think. It took a good amount of force to get the tiles up. However, as you can see in the pics below once I removed the tiles and thin set it is clear that there is water in there. In the picture you can see a crack in the cement pan that the water is coming out of. The cement around the crack is darker than the cement on the other side. This is the only place water can be seen. I am assuming because there is a crack that water is under the cement now. The crack leads right to the drain.

With Thinset



Thinset Removed

 
#12 · (Edited)
That's why a lot of people don't like that type of shower construction, that JazMan referred to as OK but not right; the principle of it is that the floor essentially never really dries and after shower upon shower just means that you're standing on wet concrete that - hopefully - has a slow drip slope down to a - hopefully - clear drain. That's not a defect - it's the way it was designed...the tiles may be water-resistant but the grout isn't and it should let water through it.

Even though the tile may be travertine, they are essentially water-resistant for the purposes of this argument, when compared to the grout.

The trouble is that it isn't only water that goes down a drain on a slow slope, so it gets clogged pretty quickly. Most showers like that develop mould and smell funky.

Now the crack in the grout may be related to that, I'm not sure, sometimes it is, sometimes not. Sometimes it's a symptom of a larger problem. But at the same time, sometimes cracks are only cosmetic in nature and they should be regrouted otherwise one tile moves relatively a bit more than the next and before you know it, you've got several loose tiles. Grout is essential to the assemblie's integrity after all...

You mentioned you vacuumed up water.sure you will as water is coming from every corner of the concrete base.

This type of construction also suffers from slow evaporative drying as water goes the other way, i.e. from the base concrete up through the grout and into the air. This is slow as there is usually no moisture concentration gradient sufficent to let it dry out completely, so putting a silicone caulk wouldonly hinder that process. So clear silicone becomes cloudy due to the moisture behind it.

I am not sure about a solution; I have tried one or two things that seem to work but I'm unsure. A huge % of showers are/were made like this and I'd say the technology has long since passed that and we don't offer that type of construction...
 
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