We have a house that was built in the 20's. The original toilet in the basement was cemented to the floor above the terra cotta pipe leading to sewer line. We have taken the old (not working) toilet and would like to put a new toilet in. However, with only the terra cotta pipe there we are having lots of trouble finding a flange. The pipe is 4 1/4", the opening widens to 5 3/4" and the outer edge is 6 3/4" - so any flange that I've tried - the holes for bolting it to the floor fall directly on the outer rim of the pipe. I tried a flange with a widening ring around its base w/ allen screws on the inner tube- but it was made for a 3" pipe. Is there some other type of specialty flange that would create a seal in the TC pipe AND be able to extend past the rim of the pipe so that I can tapcon it into the surrounding cement? WE have even been told to cement the new toilet in once we get it bolted to the floor. Every plumber we have talked to has run away - any advice?

D kirk

You have a older house with terra cotta drainage. I'm a old timey plumber that remembers those days. Why not do what we did back then before the days of cast iron pipe and closet flanges.
First off you must realize the a closet flange does nothing more then secure the toilet bowl to the floor. It doesn't stop leaks or make the toilet flush better. In short, it's not really necessary.
Bearing that in mind, If this were my call I would position the bowl over the closet bend and mark the closet bolt holes on the cement. Then I would take a 1/4" masonry bit and drill holes to accept plastic screw in inserts.
I would then purchase two wood screw closet bolts, nuts and washers and a wax seal with a funnel. Screw the closet bolts into the plastic inserts and you now have a setup that performs the same function as a closet flange.
The wax seal with a funnel is just added insurance against a leak, (back in the old days we used a rope of plumbers putty for a seal). You may now set your toilet with confidence. Good luck, Tom

Thanks so much! We got it in just in time for Christmas. Your feedback helped us to do it ourselves. Many thanks.