Advice needed on installing closet flange in basement

Old 04-20-07, 12:27 PM
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Advice needed on installing closet flange in basement

I am finishing my basement and had the builder do a rough-in for a half bath. I actually just passed the rough plumbing inspection yesterday.

I have a 3" PVC drain coming through the concrete floor for the toilet and have a few questions regarding the installation of the flange. I've looked around the web and seem to find a few different answers for the same questions. I trust these forums the most.

1. I plan to apply tile directly to the concrete floor in the bathroom. Should the closet flange be set to the concrete floor level or should I do the tile work and then set the flange to the finished floor height (i.e. so the flange sits on the tile)?

2. I am hoping that just below the concrete the builder put a insulating collor so I only have to chip away a thin layer of concrete and then remove the insulation so the flange will fit over the existing drain line. If this is not the case what is the best way to remove this concrete to the flange can fit over the existing pipe? I assume that will be a cold chisel, hammer, safety glasses, and some patience but thought I'd ask if there was a better way.

3. Is it necessary to secure the flange to the concrete? If so I was planning to use Tapcons. I was thinking this might not be necessary since the drain pipe is embedded in the concrete floor and the glue bond to the PVC is quite strong. Again I'm not sure.

4. Should I use a flange with a metal surround or plastic? My first inclination is to use metal since it is stronger and gives a little before breaking but since this is a basement insulation I am concerned about the metal rusting.

Thanks for any advice on these questions!

- Mark
Old 04-20-07, 03:42 PM
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You can glue a pvc closet flange directly to the pipe. I like to place it on top of the tile but it would not necessarily be wrong to have it on top of the concrete. Either way, it should be bolted down or the toilet, which in turn is bolted to the flange, will move. Some may disagree, but I would use a female flange. Others may say, if you have the room, use a coupling and a male flange. The stuff still flows, I say!

Don't know anything about "insulating collars" but just chip out the concrete with a cold chisel.

There's no reason to use plastic when metal is the same price. I'd rather bolt through a piece of steel than a a piece of dead dinosaurs!

Last edited by Rockpro; 04-20-07 at 03:44 PM. Reason: Some days spelling is a chawr

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