Properly built showers need water containment by various means. Tiles can be installed over a cement board wall, but requires a vapor barrier stapled to the studs behind the board and extended over the vinyl pan liner, also attached to the studs. Another way is a surface-applied membrane such as Kerdi or Hydroban directly applied on the face of the backer board and then tiled.

Difficult to tell what's happening here unless you either know the method used or can cut an inspection hole on a wall behind the shower and have a peek.

Also possible that there is an issue with the floor pan. Does the shower drain promptly?

Pictures would help......

Lazarususa, thank you for your feedback. First, if my camera decided to start working, and I took pictures, the pictures would only show the shower itself. No one has been able to determine anything from just standing and looking at the shower. Of course, if the shower was opened up it would be a different matter but it is not yet. We want to be as sure as we can before we begin tearing out the tile. You can certainly understand that.

I have the contract from the licensed tile contractor who did the work back in 2002 and maybe this will help you, I don't know but here goes:

1. Tear-out existing shower and shower pan and haul off waste.

2. Prepare walls to receive membrane and wonder board backer and prep floor and drain for new pan.

3. Install 40 mil Chloroloy pan to floor and 6" up wall and over dam.

4. Install membrane and wonder board to walls.

5. Provide and install Florida Tile 4 1/4" ceramic tile color #503 bone with matching bullnose trim.

5. Grout as needed.

The tile contractor has moved to parts unknown so we are starting from scratch.

I am wondering if it is the tile itself. I've read that porcelain tile is better than ceramic tile waterproof wise.

I am also wondering about the tile grout. Could that be leaking? Are there different types of grout that are taboo as opposed to being excellent?

We have wall water damage and don't want to get that repaired until we are sure where the leaking is coming from so as not to have the same thing happen again. It's just determining what to do first, then test, etc.

We have not used this shower in weeks and the wall is drying out.

I think, the pictures that would be helpful, would be of the wall water damage.

If you remove the cover plate from your shower valve, you should be able to see the layers that make up your shower wall. Tile, thinset, 1/2" wonderboard, then 6-mil poly sheeting, then the studs.

Wonderboard is a reinforced board made of cement, it'll look gray and have a coarse texture.

How is the water showing itself? Are there water stains high on the walls, down low, on a plumbing and/or non-plumbing wall?

Does any of the grout in the shower seem to never dry out? On the floor, or low on the walls?

Ha any work been done on the shower in the past year? A new shower head, etc?

If he did the work according to the contract properly, the wall should be sound. I see no mention, however, regarding the floor construction. Assuming it to be a tile floor, proper terchnique would be to install a pre-slope BEFORE installing the Chloroloy liner, protect the weep holes with pea gravel or spacers, then install the final mud bed with proper slope to drain.

If, for example, there was no pre-slope or pebbles protecting the weep holes, water will collect on the liner and become stagnant. This will not, in and of itself cause a leak...just begin to smell, grout on the floor and/or around the drain will stay wet.

Now, IF he attached or nailed the liner low on the walls or anywhere on the curb except for the outside face, this could compromise the integrety of the pan and cause the problem you have. Watch for persistant moisture particularly near the drain...it's a red flag.

Additionally, there could certainly be a problem with faulty plumbing...more likely if only the wall with the controls is wet. Remove the cover plate, as Mongo suggests and use a light to see if there are any wet fittings there. You might try removing the shower head and temporarily cap the pipe, turn on the controls to pressurize the system and look for leaking pipes or junctions.

As I mentioned earlier, easier and cheaper to cut a hole on the other side to better inspect. Drywall is easy to fix...

As to your question regaring types of tile, makes absolutly no difference...and grout is not waterproof. The tile is there for one reason only; to make it look pretty, not to waterproof anything. The proper construction is what provides water integrity. With a properly built shower, you can use it safely with no tile at all in place.