shower pan made out of concrete?

To properly build a custom shower you need first to build and shower curb and pre-slope base that would slope 1/4 in per foot from walls to the drain. You need to use special shower drain that consist of two parts, one screws into another. This type of drain also has weeping holes intended to collect water from pre-slope base into the drain. Pre-slope base should be flush with lower part of the drain. You put shower pan liner on the pre-slope base ensuring that it goes up on walls at least 12 in, goes fully around shower curb including outside side. You never cut the liner on corners. In corners where shower walls meet you fold the liner, on outside corners where walls meet with curb you use special outside corners manufactured by the same manufacturer as your liner. I used Qatey PVC liner but CPE will work as well. If you need to glue two parts of the line as your shower is larger that the liner width you use special adhesive ensuring that two glued parts overlap at least 3 in. You only staple the liner at very top on the walls, you do not staple anywhere else. You put the liner over lower drain part and screw up the upper part. Then you accurately cut the liner for the drain hole. Then you unscrew the upper part and put silicon caulk between lower drain part and the liner. Now you can build upper part of shower base. Some people suggest using wire mesh for both lower and upper part of the shower base. I used 5-1 ratio of sand to Portland cement with no wire mesh. To build a shower curb you use different type of mix similar to one used to lay down bricks that has lime. It is sold premix so you can just add water. Last moment. After you built lower part of the shower base and put the liner up. Plug the drain and fill it with water till the curb. Leave it for 24 hours. If you see that no leakage occurred you base is waterproofed if water leaked you need to find the leak in the liner and glue a patch over the hole that causes the leak. Repeat test again until you find no leaks.

"david" wrote in message news: snipped-for-privacy@c13g2000cwb.googlegroups.com...

"david" wrote in news:1102397547.321065.326890 @c13g2000cwb.googlegroups.com:

No sense at all -- unless you really want to live with the resulting leaks, moisture, and mold problems. You would be amazed at how much water can leak right through concrete.

Build or buy a proper waterproof shower pan.

Go

Gary Please remove XXX in email address if email reply is desired.

Thanks. I've previously researched the floating mortar bed type with the membrane and know what would be done in that case. My question was more why I couldn't get away with using concrete as it would prevent me from having to tamper with my existing shower drain (dig it up, try to attach a new drain, etc..).

Murray suggested mold and leaks. This plumber suggested coating the concrete with a water resistant 'paint' of sorts (don't remember the name). I should be able to test for leaks by filling it up afterwards.

I think his point was that it's a lot of work to tear up the drain and any leaks into the ground are not a problem if it's in the basement, only leaks out the sides. If the concrete could adequately seal the edges (much like the curb would do---I have a concrete curb as it is already) then why deal with the drain?

There are a variety of paint on membranes for under tile installations. Red Guard made by Custom Building products is available from Home Depot. If you go this route you want to waterproof the entire shower, not just the floor. A typical shower pan allows for any moisture that wicks through the grout to find it's way to the pan and down the drain. By going the paint on route you would be preventing this. You need to make sure that no water penetrates the wall material....

prevent me

afterwards.

basement,

installations. Red

penetrates the

Thanks. So to make sure I understand, you're suggesting I can use a concrete 'box' as my shower pan provided I coat the concrete, before applying the thinset, with this paint (e.g. Red Guard).

I presume you mean to paint it on all the concrete, not just the floor as opposed to the whole shower. I will be using concrete backerboard for the walls so it makes no sense to put this paint on the backerboard right?