Old House Installation Challenges

[WildOne]

I'm at my wits end, thinking that building a pedestal for the base of my toilet is the only option

The situation: 1912 house with 1/2" for every 15" slope in floor from outer wall to bathroom door with toilet tank oriented in direction of slope, cast iron main stack, original plumbing except for cast stack recently replaced with copper, drain system in bathroom replaced with ABS, new 1" plywood floor installed but not leveled by contractor (possibly due to large step that would result at hallway entrance to bathroom?), 3/8" subfloor and ~ 5/16" tile/mortar installed up to drain pipe.

The problem: underfloor depth and toilet distance from stack make it so that I have no standpipe; there is ~ 15" of sloped drain pipe (ABS) attached to original cast stack and then the 45 deg elbow whose top edge sits ~ 0.8" below the finished floor - a 3X4 closet flange can only be inserted 1 5/8" max into the elbow due to elbow depth and change in OD of flange (bulged portion which creates wax ring bed.)

Short of creating a platform e.g., concrete pad/pedestal for the entire toilet, I see no other way to screw the closet flange to a flat / level surface nor ensure that the toilet is sitting level.

This forum featured the most in all my searchings and provided the most comprehensive tips / advice. Hoping that it can do the same for me

[breid1903]

1/2" in 15" is .4" a ft. 3/8" is .375 a ft. does the drain have fall? if not all bets are off. if all of that works. good. you will need googles, ear plugs, gloves and probably knee pads. get a dye grinder or dremel tool. set flange on pipe loosely mark outside of flange. turn over measure to "hump" grind out extra. if much, dremel will burn up............... why does stool have to be level? no matter what you do here stool will look odd, but so will everything else. is anything in house level? if you are concerned about whether toilet will work, build a little test setup and try it.................. you will need to have a hanger to hold pipe behind flange. you may have to trim flange to get it to fit. put on two, maybe three wax rings, no horns...............if you want to level stool cut a couple shims to hold up stool. mix up some very thick cement. grout stool. you will need a big enough dowel rod to shape mix under stool. do front, let set. pull shims, do rest. then put a skim coat of the tile grout over the cement. it'll look like you know what you are doing.............is there room under stool? if so good. if not you will have to grind out room for it. set stool on floo............you can do it. if i can do it, you can do it. keep us up dated. breid