View Full Version : Shower drain in slab

10-23-2005, 07:21 AM
I'm installing a prefab acrylic shower unit (one piece) in the basement. The ABS trap is already roughed in and I have a two piece ABS drain (see http://www.johnlschultz.com/site/products/products-more.asp?part=133-113). The body of the drain solvent welds to the drain pipe and the strainer screws in from the inside of the shower. I am planning to dry fit and measure everything (several times) before gluing it all up. Is there any other trick to getting it all aligned properly before setting the shower unit in place?

10-23-2005, 07:34 AM

there is a different drain that you use for this application. its a rubber sleeve inside the drain. You install the drain on the bottom of the shower and then slip the shower over the 2" trap tailpiece. Insert the rubber sleeve on the tailpiece and cut off the excess height using an "inside pipe cutter". tighten the sleeve down with the provided nut and its watertight.

10-23-2005, 07:48 AM
I thought about using one of those "no caulk" drains, but I'd rather use the glued in type (less chance for leaks). That's what seems to be used mostly around here (eastern Canada). I have this type in the second floor shower already. Easier to install since there was access to the floor from below.

10-23-2005, 02:15 PM
Another thing to seriously consider is to put down some material to fully support the shower base (deck mud, plaster of paris, etc - check the instructions). Check the instructions, they usually list this as optional - you will be much more satisfied if you make that mandatory.

10-23-2005, 06:04 PM
Yes, I will do that too. There is a piece of 1/2" plywood on the underside of the shower floor and then it's about 1 1/2" from there to the subfloor. I was thinking of just using some minimal expanding foam. Still haven't gotten a consensus on the best type of drain to use. I will try to ask around at some plumbing supply shops to see what is most common in these parts.

10-23-2005, 08:34 PM
You'll be better off with something like deck mud (concrete with a lot of sand) or plaster of paris or whatever they recommend. Problem with the foams is either they're flexible or hard. If hard, they can crumble under point loads and if flexible, you'll still end up with microfractures in the base eventually. That crazing of the surface finish and flex while standing there make it look poorly and feel cheap. Fully supporting it will make it last longer and feel much more substantial.

Gary Swart
10-23-2005, 09:45 PM
The shower should be set on mortar, but it doesn't have to cover 100% under the pan. Getting most of the underside supported will be fine. As far as the connection is concerned, a flexiable connection won't crack if there is a bit of movement. I think you're incorrect about a glued joint being less likely to leak.

10-24-2005, 07:16 AM
What about drywall mud? Would that work just was well?

10-24-2005, 12:02 PM
I'd use the proper size rubber seal that you drive into place.

Gary's right on.........