Basement toilet mounted on plywood?

[wingdude]

Hi I installing a new toilet in the basement of a house built in the 1970s.
The old one was mounted on a 3/4" piece of plywood profiled to match the bottom of the old toilet. When I removed the toilet I found three studs (1/4" concrete anchors) w/ no nuts on them to secure the plywood to the floor. One in the back and two in the front. The plywood has two carrage
bolts coming up through the plywood to anchor the toilet? The sewer pipe is 4" cast iron "street L" I beleive, which sticks up out of the concrete about 3/4".
There is no flange w/ t-bolts in the floor. What would be the best way to mount the new toilet? I could cork the sewer pipe w/ wet rag and cut the pipe flush w/ the floor using a cut off wheel and set anchors to mount the toilet or make a new chunk of plywood to match the profile of the new toilet.
Please advise me as to what would be the best way to go.

Thanks,
Doug

[Marlin336]

The right thing to do would have been in install a lead bend under the slab or have the elbow down far enough that a piece of cast iron pipe was coming up. It doesn't sound right that the elbow itself is exposed. You're sure you have a cast iron elbow sticking up and not a piece of lead right? If you could get a couple pictures of the situation it would help.
What you have right now is a hack job, and using another piece of plywood would be another hack job. Someone else will come along with a more solid answer but you may need to have a plumber come and pour a new flange into place or you may be able to use one of those internal compression flanges.

[markts30]

Sounds like a cast iron closet bend...
The install is a bit too high but can be cut flush...
Do you have room on the outside of the pipe for a flange?
What is the ID of the closet flfange coming through the floor?

[master plumber mark]

I just love a challenge like that one

especailly on a Sunday Morning.....with no stores open

You have opened a can of nasty stinkey worms.....

Now you have to deal with it...

here are few suggestions that have saved my life before


1. you might get lucky and go out and get an OATY Expanding Flange for a 4 inch pipe.....
It might just go down into the 4 inch and save you much greif and misery.... but dont bet on it...


2. you might have to chisel out around that cast iron
to make a lot of room for a new cast iron 4 inch flange..
get a tall 6 inch flange....about $20 bucks...


if you have broke out about a 3 inch gap around that pipe you have plenty of room to work...

caulk the flange into place...to the right height for it to be sitting on the new plywood?

how that is going to work with the new plywood is
something you just have to figure out for yourself.


Go out and buy a large amount of hydrolic cement

Caulk and set the 6 inch flange to the height that you need and use the quick setting hydraluic cement to pour back around the concrete you have broken out

the expanding cement will actually get hot and
the flange will never move again
and as long as you have put it to the right height

you probably will win

you only get one shot at this approach..

have fun this Sunday Morning.


.

[patrick88]

bolts coming up through the plywood to anchor the toilet? The sewer pipe is 4" cast iron "street L" I beleive, which sticks up out of the concrete about 3/4".

you may be able to use one of those internal compression flanges.

I would open the floor and remove the cast iron as far back as i can. Replace the cast iron with 3" plastic so you can get enough room. This should give you enough room to set the toilet on the floor like it should be. Those internal compression flanges tend to be a bit long so trying to get it to into a street ell probably will not work.

[wingdude]

Go out and buy a large amount of hydrolic cement

Caulk and set the 6 inch flange to the height that you need and use the quick setting hydraluic cement to pour back around the concrete you have broken out

the expanding cement will actually get hot and
the flange will never move again
and as long as you have put it to the right height

Can you tell where to get the hydrolic cement?

What height do I set a new flange (flush w/ the concrete) or on top like I've seen on wood flooring.

Thanks, Doug

[jadnashua]

You can buy hydraulic cement at a big box store. It comes in small pails or boxes. Only mix enough so you can use it in a few minutes, as it hardens quite quickly. What is different is that it expands a little as it sets, so it can seal holes.

The toilet flange is designed to sit on top of the finished floor, and be anchored through it into the subflooring (in this case your slab). If it is held well in concrete, you probably don't need to use any anchors, but it doesn't hurt. If you were going to say tile the floor, you might be able to make it high enough so that you wouldn't have to cut off any of the pipe. If it is going back on the slab, then you'll have to cut it back some. most modern toilets only have maybe 1/2" or so ring for the flange and the wax (maybe a little deeper, depends on the toilet). So, the toilet won't sit properly without doing something to the pipe.

As was mentioned, an internal compression flange will fit in a normal 4" cast iron pipe, but because of the elbow's curves, you may not have enough room to make one fit.

If you were willing to crack some more concrete, you could cut it back far enough to transition to 3" pvc, turn it up, and mount a normal flange. You could have someone do that in CI, too, but it might be a lot more work. The pipe may not be deep enough, and working with cast is a lot more work.

[Mike Swearingen]

A toilet flange should set on top of and be bolted to (Tapcons are good for concrete) the finished floor level with only the thickness of the flange above the finished floor level.
Mike

[geniescience]

plastic sleeves will do, for a toilet flange. Plastic anchors or sleeves, that you screw any ole galvanized screw into. Even dowels will do. And if you are working with hydraulic cement or any other wet cement, you can just embed any old galvanized metal (bolt, screw, whatever) into the cement. The reason is that all the strength you need for a toilet flange is a bit of prevention, so it is not going to slide or rotate in the hole. If you use a stronger fastener, fine, you will be able to hang a car off that toilet when you fasten it to the ceiling.

david