Rusted out toilet flange on 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 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 i'll have at least 1-1/4" inches of concrete betwen the holes and the outside of the PVC.) Then I'd 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. Seems to me they should hold the toilet down as well or better than that pressed steel toilet flange did.
Anyone else do it this way? Or, is there a reliable repair flange made for this kind of thing that won't require my having to drill into the concrete anyway to anchor it down?
Thanks guys,
Jeff
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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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In the old days with lead drains this was how all WC bowls were fastened down on all types of flooring. In your situation I'd be thinking like you and anchoring the closet bolts to the concrete.
MM
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Yeah, they make a flange with a rubber collar. You simply slip it over the pipe that remains and tighter it down. As it tightens, the rubber forms a seal. You can buy a cheapied for about $18. The more expensive one (cast iron) will cost you about $35. Go ahead and spend the $35.
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Blackbeard wrote:

Thanks, but the concrete floor level is only about 1/4" below the underside of the flange on the remaining plastic portion. So, I couldn't clamp around the existing (plastic) pipe without busting out a lot of concrete.
I did spot this two piece galvanized steel repair flange which looks like it would pretty much replace the original rusted out stamped steel flange:
http://www.quickfixplumbingproducts.com/repflg.htm
The plastic portion of the photo on that page looks just like what's left in my setup.
But I wouldn't trust using that repair flange without fastening it down with screws into some kind of expansion anchors set in drilled holes in the concrete. Without doing that, all the upward pull would be born by the flange on the plastic part. Might be strong enough, but that's not the kind of work I like to put my name on, and since my labor is free, why not do it right this time?
Jeff
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Jeff Wisnia (W1BSV + Brass Rat '57 EE)

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"Jeff Wisnia"
Are you trying to repair this without drilling? That would be nuts. If the concrete is fairly close to the flange, then get a collar that'll glue on the pipe. They make the type for 3" and 4" that will slide like a trombone, then anchor the collar with lead hammer pin anchors. If the concrete is too far away, then pour that repair stuff and put in the screws while it's still wet, or buy that flat steel plate that's make for a collar, but is about 12" square, so that you can firmly anchor the plate, which will firmly hold the collar, which will firmly hold the toilet.
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Mike Grooms wrote:

Definitely not Mike, I don't do things half ass, except in dire emergencies, then I go back and make 'em right as soon as I can.
That would be nuts. If

The concrete was poured completely around the PVC, so there's plenty of solid concrete to drill into at the two toilet base mounting hole locations.
What was used looks like the first photo on this page:
http://www.plumbingworld.com/toiletflanges.html
only the metal part wasn't stainless steel dammit, or I wouldn't be having to repair it now. <G>
The flange on the of the remaining plastic part of the original PVC/metal piece is in perfect shape and plenty wide for a wax ring to seal against.
I'm gonna follow through with my original plan, which is to drill two 1/2" diameter holes two inches deep into the concrete, drop in 4" long 5/16-18 galvanized carriage bolts (with the heads turned down to fit down the holes) and then fill the holes with Rockite, which is a quick setting pourable Portland cement that expands on curing, used for setting machine tool anchor bolts into concrete.
FWIW the original installers (18 years ago) didn't bother to drop any screws through the holes in the stamped steel closet flange before they poured the concrete flor around everything. So, the only thing holding the metal flange down was the PVC part.
The concrete floor and the ceramic tiling over it where the toilet sits isn't exactly flat either, and there was no sign of plumber's putty or shims under the toilet. I'm sure you've seen plenty of "not quite right" installations like that before. I intend to do it better than they did.
Thanks again,
Jeff
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Jeff Wisnia (W1BSV + Brass Rat '57 EE)

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why can,t you cut and peel out the old plastic and glue a new flange down?
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