toilet install warm-up

amakarevic · 06-23-2008, 01:34 PM

two questions before i am ready to seal:

1. i noticed two different kinds of flanges to choose from: one with a loose metal ring (which gets tightened) and a solid PVC one. what are the different applications ?

2. the underlayment is concrete (basement apartment). when i poured concrete, i set a red plastic cap on the 3 in pipe that provided spacing around the pipe relative to concrete (1-2 inch) so that a flange can be set. once i do set a flange, is it necessary to remove the plastic mold (i have since cut out the top) and fill in the round gap with something like mortar patch or can i just leave it hollow ? even if i left it hollow, the spacing is narrower than a flange so it would be covered but i was thinking that filling it might provide a more solid base for the weight of the toilet.

thanks,

- a -

mstplumber · 06-24-2008, 03:01 PM

I like the flange with the metal ring. It is a little stronger and allows room for the wax seal on toilets with a shallow recess under the bowl.

I would definitely fill the void around the toilet with concrete, for the reason you mentioned. This will just help prevent the toilet from rocking and wobbling. If there is enough concrete left under the flange it would be a good idea to anchor the flange to the concrete. This may not be possible if the hole is too large.

amakarevic · 06-24-2008, 03:24 PM

thank you sir/madam !

mstplumber · 06-24-2008, 05:59 PM

You are welcome. It's sir by the way

amakarevic · 06-24-2008, 06:19 PM

one can get in trouble by assuming that in any context these days.

Alan · 06-24-2008, 10:36 PM

We don't like the metal rings, because they can/ probably will rust out over time. There's no saying that the plastic won't break, but it will probably last longer.

mstplumber · 06-25-2008, 08:55 AM

I have used plastic rings for years and lately have began to have problems with the recess around the toilet outlet being too shallow. In some cases the plastic flange actually holds the toilet up off the floor without even having a wax ring installed. I had an engineer from a very well known toilet manufacturer tell me that was so the flange could be installed during rough in and then the underlayment for the flooring installed, leaving room for the wax. I know many people do it this way, but if hardwood or tile is installed around (and sometimes over) an already installed flange, it often leaves a bigger gap than a wax ring is designed to fill. There are spacers made for this purpose but they just create more opportunities for a problem.

Plastic flanges are also pretty bad about breaking if the toilet bolts are overtightened. They even make several products specifically designed to repair broken plastic flanges, so it's a fairly widespread issue. The other side of the coin is that a metal flange requires the installer to be more careful when tightening the toilet bolts so the toilet doesn't crack.

The bottom line is that although I've used plastic flanges for years, apparently many toilets now don't work as well with them as in the past. An easy way to check this is to turn the bowl upside down, hold a flange in place and lay a straight edge across the bottom of the bowl. You should have 1/8" to 1/4" space between the bottom of the flange and the straight edge. This will allow the wax to properly seal the toilet to the flange when it is installed.