leaking behind bathtub/shower tiles

I bought a new house in 2002 with a standard bathroom. Water leaked from the tub/shower area and went through to the living room. The builders came back to repair. I thought it was because the tub was not level. They levelled it and took out about a foot and a half of tile and retiled that with extras that were left over from the build. Then ceiling in the livingroom was repaired and fellows came in to refinish it. It took a lot of work and co-ordination with a lot of trades people to do this. It was ok for a while and then it was starting to spot in the livingroom ceiling again. Using a level, I saw that the tub still was not level. This time I had a handyman (from a trusted friend) come in. He saw that the tub didn't have supports under the outside edge and so used a series of shims. He removed the quarteround down the length of the tub because it was rotting. He caulked the whole thing well. (There was quite a big gap between the tiles and the tub that the builders had left.) This lasted for a long time, but the last few months there has been water leaking again. So much, that we have towels to catch it on the living sofa and carpet. A "master plumber" was in. He said it was water getting in behind the tiles. There are cracks around all the replacement tiles that the builders had fixed. He examined the wall and said it was soft behind the tiles for about a foot and a half down around the tub. (go figure!) and that it was probably tiled on regular dry wall. He said he could repair the bottom part of the wall and retile and I could get someone else to fix the ceiling.

From reading your other threads on leaks behind tiles I see that he seems to know what he's talking about. My question is though, how do I get these problems fixed finally and forever? Do I get this plumber, who says there's nothing wrong with the plumbing, to do a repair that involves tiling? And as there's no repalcement tiles, that would mean getting the walls retiled in something else. So should all the backerboard be replaced? How do I know there isn't mould under the bathroom floor and all the way through to the livingroom ceiling?

Help.

The best place for help on tiling is www.johnbridge.com. Tile on drywall is only good in dry areas...a tub/shower is NOT a dry area.

Plus, there should be a vapor barrier behind the cbu (cement backer unit, aka cement board). This should lap over the tiling flange so any moisture that gets behind (and it will) can be directed back into the tub, not down the wall.

Plumbers don't usually do tile work. Doesn't mean they can't - a craftsman often has many skills, it's just they usually don't.

A tub needs to be level.

Thanks for the help.

Does a drywall installer do cement backboard?

Why? Seems as though you should just find a tile guy. Almost like asking if plumbers do electrical work. Most times no but there me be some. Just because our work goes through the same walls as "sparkys" doesn't make us one in the same. Nor should it for professions that have walls as their commonality.