Rusted out toillet flange in concrete floor..

From the department of one thing leads to another...
I noticed the fill valve in a seldom used basement bathroom toilet wasn't shutting completely, so I ran and picked up a Fluidmaster to replace it with.
The replacement was a no brainer, but while leaning on the toilet to reach the shutoff I noticed the toilet shifted on the floor slightly.
I soon discovered that the pressed steel toilet flange was badly rusted, and the flange bolts had pulled through it, That steel flange was held down only by the flange on the end of the PVC drain fitting.
A few minutes work with a hammer, chisel and pliers removed all the remains of the pressed steel flange. Now I just have the PVC drain, surrounded by concrete. (With a piece of foam rubber and a few bricks keeping the sewer gas where it belongs for the time being.)
My thought is to use my hammer drill to sink two holes a couple of inches deep in the concrete at the appropriate locations, (Looks like a hole span of about 6-1/4" will be just right for that toilet.) drop in a couple of 5/16" brass or stainless bolts and fill the holes with Rockite, the stuff used to set machine anchor bolts into concrete floors. That should let me put on a wax ring and lower the toilet down over those bolts. They should hold the toilet down as well or better than that pressed steel toilet flange did.
Anyone else done it this way? Or, is there a reliable repair flange made for this kind of thing that won't require having to drill into the concrete to anchor it anyway?
Thanks guys,
Jeff
--

Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"As long as there are exams in public schools there will be prayer in
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Jeff Wisnia wrote:

I like your method. You can replace the steel flange ring but that still leaves the PVC flange without solid anchoring. Go for it. Jim
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Jeff,
A flange and wax ring should definitely be used to make the seal between the toilet and the pipe. You can get a plastic flange so that it won't rot away again. It will need to be screwed to the floor though. You should be able to use #10 x 1-1/2" stainless screws with sleeves to attach the flange. Then, use conventional brass toilet bowl screws, washers and nuts to fix the toilet in place.
Bob

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<< My thought is to use my hammer drill to sink two holes a couple of inches deep in the concrete at the appropriate locations, (Looks like a hole span of about 6-1/4" will be just right for that toilet.) drop in a couple of 5/16" brass or stainless bolts and fill the holes with Rockite, the stuff used to set machine anchor bolts into concrete floors. That should let me put on a wax ring and lower the toilet down over those bolts. They should hold the toilet down as well or better than that pressed steel toilet flange did. >>
Sounds perfectly sane to me.
<< Anyone else done it this way? >>
Yes, worked great. I used 5/16" threaded stainless rod instead of bolts (had it on hand).
<< , is there a reliable repair flange made for this kind of thing that won't require having to drill into the concrete to anchor it anyway? >>
Even if there was it won't work as well as the proposed threaded anchors. HTH
Joe
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Joe Bobst wrote:

It went according to plan for me too, I couldn't readily get appropriate sized brass or stainless threaded rod so I bought a couple of 4 inch long 5/16-18 galvanized carriage bolts, washers and nuts and turned the heads of the bolts down a little so they would fit down the 2" deep 1/2" diameter holes I drilled into the concrete floor.
I think I located a possible reason why the steel flange rusted out. I noticed that the concrete floor (Which is covered with 1" square ceramic tiles.) was far from flat where the toilet sits. It looked like the sods who built the place for us 19 years ago located the flange maybe 3/8" higher than it should have been and troweled the cocrete toward it so that it was at the top of a low hill.
I test fitted the toilet without a wax ring and it rocked fore and aft, I could create about a 3/16" gap at the front end when it was rocked backwards. There was no trace of shims or grout under the toilet when I removed it, so it may have rocked enough in during use to let the wax seal leak a little, causing the rusting out of the steel flange, or maybe it was just water from floor washings going under the toilet.
In any case, using brass hold down bolts with a steel ring in a damp location guarantees that galvanic corrosion will attack the steel, and it'll be corroded worst right where the two dissimilar metals touch each other.
After I put in the wax ring and snugged the mounting nuts down I wedged a couple of plastic shims in the gaps between the toilet and the floor and then pushed grout under it wherever it would go. The next day it was impossible to make it rock.

I'm confident that my repair job will last longer than the original "professional" installation did. I think it's "done right" now, and thank G-d I didn't have to pay someone else to fix it for me. <G>
Jeff
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Jeff Wisnia (W1BSV + Brass Rat '57 EE)

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