Designing Kitchens and Bathrooms - Is my shower being built correctly?

I am having a new shower installed where an insert used to be(completely tiled, floor and walls). The man installing it has been doing this type of work for years. I don't know anything about tile but it seems to have something missing as far as waterproofing goes. Heres what he has done so far:

Step1. Put down 1/2 inch salt plyboard on floor.(on top of linoleum flooring)
Step 2. Poured concrete approx. 3 inches on top of that.

Now he will put concrete board on top of that and lay the tile on top of that.

He has framed the walls and bench seat of the shower to the original sheetrock walls which he will then cover with concrete board and then tile.

Should there be some type of water barrier such as rubber or plastic or something that goes in there somewhere? Should the seams between the concrete board be siliconed. It is costing a lot to have this done and I am a little concerned. Please help fast 'cause he'll be back tomorrow!

I think you need a new installer. That shower pan is not even close to being done correctly. Check out this link for basics on shower pan construction.

http://www.ontariotile.com/preslope.html

For the walls, the sheetrock should come down and cement backerboard and a vapor barrier should be installed to the stud walls. There are lots of other things to concern yourself with when constructing a shower but for now you gotta get that pan situation fixed before he goes any further.

After reading your reply to my question. I contacted a reputable tile installer who came over right away and advised me that I was going to have serious problems with my shower if I didn't correct it at once. Now all I have to do is tear up a couple hundred pounds of cement and start over again as opposed to finding out 2 years down the road that I once again need a new shower and possibly a new floor. Thanks so much! Lawdawg

P.S. Any other advice you might have on this subject will be eagerly accepted.

Theres alot to know about building a custom shower. If you have specific questions, ask away? Yes its much better to correct the problems know than to be faced with a total redo shortly after its completed. Good Luck.