shower stall design/construction: your experiences?

Using a prefab shower pan is probably the easiest to use (If you use this, you'll need to put down a mortar bed below it to stablize it).
You'll probably get more bang for your buck if you put in a custom made shower with curbs. Make sure that you use pressure treated wood for the frame with cement backer board for facing. Sloping to the drain will require a viscous mortar mix and reinforcing mesh. On top of the sloped mortar I would put a shower pan membrane (Chloraloy) to water proof it and divert mosture back to the drain. Make sure the first part of the drain (of a two piece screw-in assembly) is installed first before putting in the pan membrane. The membrane needs to be folded correctly at the corners to allow moisture do drain positively (there should be directions on how to do this in the membrane package.) On top of this membrane, you can proceed to thinset and apply the tiles...For the shower surround, I would use cement backer board as the base and then apply thinset/omnigrip prior to tiling. Make sure that the thinset/omnigrip is applied at an optimal temperature for vertical applications since any other temperature may cause the tiles to slip and droop...no worries for horizontal tile applications.

I'm not sure if the radiant pipes stop at the shower stall...It could go either way since continuity of the pipes would be faster to construct but stopping short would be more efficient to the homeowner.

Residential building codes are more lax than commercial building codes...The Americans with Disabilities Act would probably not apply to your house unless you plan on using it as an elderly care home or some other more public use. Original Eichler bathrooms wouldn't be the appropriate size in any case. I would stick to making your curbs no higher than 3 inches.

Water proofing any shower/tub enclosure is essential to avoid and damage to the surrounding structure and to mitigate possible mold issues.

Hi Red,

> 1: where do your radiant heat pipes stop (our are non-functional in there)? do they go into the shower stall itself or stop short?

In MY house they stop short.

> 2: does your shower have a curb or is it simply recessed about 3 inches?

I think Code in my area requires a curb, so I have a curb.

> 3: how did you go about installing a waterproof basin? did you? our original had no waterproofing techniques done where the wall met the studs. did you install a curb? door?

Hot Mop is the best. Curb which was 2x4 (3) nailed together over lapping with an offset and the Curb is attached to the wall with metal brackets to a 4x4. The bottom 2x4 is nailed in to the concrete as well.

> 4: how did you adjust the drain for the preferred 2in drain of modern showers?

Put in all new drain in new location.

> 5: did you dig out your drain and p-trap and replace with newer-style materials?

Yes. The old pipes where in the dirt and well corroded.

Cheers,

-- Ralph

thanks ralph and surfer.

i'd prefer to do minimal digging, but to do a membrane or kerdi shower properly, i'd need to at least swap the drain with a PVC or ABS 2in model which means dealing with the iron pipe to some extent and fiddling with adapting the sizes. i could wrap with the kerdi membrane all the way down to the original-style 1-1/2in drain (and just replace the drain-head itself and get a fairly decent seal, methinks -- certainly better than the original).

i've found some good materials online at john bridge forums, but the eichler is a bit of an odd beast and most folks like to tear it out and add a tuscan-look spa. we just want to retile and refresh in the original aesthetic which means curb-less (which also means not raising the existing shower floor). we're not changing anything but the tile itself. no expanding, etc.

otherwise, how much concrete did you need to bust up to get to the pipes? how far short do you think the radiant heat pipes stop from the lip of the recess/curb?

I'm trying to visualize what your situation looks like. Does the drain look like an iron p-trap within a square hole in your slab? When I replaced my tub that's what the drain looked like. To adapt the PVC fitting to the iron pipe, I used a pvc adapter to get it as close to the size of the iron pipe and then to get a good seal I used plumbers epoxy. I tested it out for leaks after one day of curing. The joint is pretty tough and doesn't leak. Your suggestion of wrapping the kerf down to the original drain might work but I'm not sure if the kerf might cause a clog later on in the future.

my current drain is a dish-shaped unit threaded directly to what i presume is 1-1/2 iron pipe. there is the perforated cover that goes over the dish-shaped body to finish off the drain. if i were to wrap with kerdi, the hole at the drain would be smaller than the dish-shape itself and the drain would mount down onto it -- perhaps sealing with a bit of silicone/kerdi-fix. the joint would be similar to a compression-fit seal. (see illustration).

the proper kerdi drain has the membrane coming over the top of the flange, so obviously, gravity and flow help it not to leak in the "approved" install. in the above "modified" design, the watertightness of the shower would depend on the compression-type seal (remember, the drain screws down) fortified by the caulk rather than flow and gravity.

than again, the original 40-year-old shower was in no way watertight (not even a poly vapor barrier) and we're mold/damage-free... so even a small infiltration at the drain location could be seen as insignificant.

the goal is, of course, not to modify of bust-up too much stuff to retain the originality and the "it aint broke"-ness of the current set-up.[/url]

hmmm, tough situation. It might work though. Relying on the caulking may be risky. I would probably do the same thing except maybe replace the caulking with a generous amount of plumbers epoxy instead. Otherwise, I see no other solution unless you are willing to hammer out some mortar/concrete.

> otherwise, how much concrete did you need to bust up to get to the pipes?

I don't recall, maybe less than 5 inches? but it was done by someone else with a chipping hammer in a couple of hours.

> how far short do you think the radiant heat pipes stop from the lip of the recess/curb?

Since we had to run the new pipes underneath they chipped back several inches and did not see any radiant heat pipe but your mileage may very :-) Pouring concrete with radiant heat pipes floating around is not an exact science so I would guess every house varies a lot in this regard.

-- Ralph

Hey Redneck,
Keep us posted.
I am in Rancho San Miguel as well
and my bathroom is still orig but needs
help.
Not going to change any design and don't want to dig.
too much.
Hoping to retile with 4" on wall and 1" on floor as is now.
Have no visible Moisture damage and hope that replacing pan
will be good. Do not want to change location of drain and have this turn
into massive plumbing project.
Good Luck
Gerald