floor mount, rear outlet toilet install

[dsw]

I'm installing a floor mount, rear outlet toilet (Gerber Pressure-Assist 21-310). The installation instructions are specific but make no mention of how the flange should be attached to the wall.

This is a residential application with drywall in and cement board lap siding on the exterior.

Do I need to expose the framing and add blocking for the flange to be screwed to?

[PLUMBER RICK]

Re: floor mount, rear outlet toilet install

the rear outlet is typically used in commercial work, multi-story.

the big issue is that when it comes to new flooring, you have to keep the toilet at the same elevation and not raise it with tile or wooden flooring.

now back to your question

the flange needs to be secure in the wall, just like as if it was in the floor.

so yes it needs proper backing.

take a 2x6 or 2x8 and either drill the hole in it, if the flange is not installed. or drill it and rip it in half to install if the flange is there.

remember that the toilet still has bolts that screw into the floor to secure the toilet.

why the rear outlet?

rick.

[dsw]

Re: floor mount, rear outlet toilet install

Rick,

Thanks for your insight. I will open the wall and block it appropriately.

The "why" question is not a short answer, but here it is:

An elderly woman lives in her almost new house next door to her daughter. These houses are in the "hollow" in the Ozarks. To save having to put in a new septic system the builder installed a composting toilet. It's a nice unit that would most likely perform as advertised except for the elderly woman's inability to perform the routine maintenance. It's gotta go.

The solution was to then cut through the slab and install a conventional gravity toilet and run the soil line some 170' to the existing septic @ the other house. No problem there. Could have / should have been done when house was built.

Found out the there were problems with the monolithic pour of slab and beams and the slab at toilet location may be as much as 9" thick. Rear discharge looks like the best solution. The vent can be run outside the wall and up through the eave. Not pretty, but it is in the back of the house and won't be seen by anyone but the occupants.

I'm OK with the installation except for the requirements for flange attachment to wall. I will remove drywall and install solid 2X12 blocking through which to bore the hole for the flange.

dw

[Chemeng]

Re: floor mount, rear outlet toilet install

I'd rather cut/core the 9" concrete.

[dsw]

Re: floor mount, rear outlet toilet install

Chemeng,

I would too except that the flat work is inside of several (I'm guessing 4) cinder blocks (high) that are the outside surround. To bore through the slab would mean breaking through the blocks and excavating out through the cinder blocks.
No one seems to remember how thick the slab is in that location...

dw