During toilet replacement, it is quite common to find that the present toilet flange is not compatible with the new toilet.
With a concrete subfloor, it can be quite difficult to replace the flange since it requires drilling holes in the concrete in order to secure the flange.
In any case, this task can be accomplished fairly easier by the use of two specialty tools – a hammer drill and multi-tool or related cutting instrument.
A home improvement store offers cheap hammer drills for rent or purchase. If you will rarely use a hammer drill, then you should only consider renting one.
A power tool will be needed to cut off old bolts. This can be either an angle grinder or an oscillating multi-tool that has a blade capable of cutting metal.
Toilet Flange Repair: Cut the Old Flange and Any Obstructions
After the toilet is removed, you will likely discover a toilet flange which will need to be removed alongside any obstructions prior to the new flange installation.
On concrete floors, there will be bolts rooted in the concrete which hold the old flange.
Hack the bolts off as well as any other visible obstructions using a multi-tool with a metal-cutter or an angle grinder. Ensure that these cut pieces are flush with the concrete perfectly.
Remove the Existing Wax Ring
After removing all obstructions, you will find the old wax ring round the opening of the drain. Carefully remove the entire old wax ring. Have a plastic bag nearby to deposit the debris for disposal.
Fit Your New Toilet Flange with New Bolts
In your new toilet flange, position the new bolts downside-up such that the threaded ends stick up.
With the bolts set, you can better imagine the positioning of the toilet.
Set the Toilet Flange
Push down on the toilet flange so that it goes in the opening of the drain, while referring to the T-bolts for positioning.
Ensure that the distances between both bolts and the back wall are equal, so that the toilet tank can align properly with the wall.
Drill Holes in the Concrete
Use a hammer drill and a quarter-inch masonry/concrete bit to bore four equidistant holes round the ring right through the toilet flange holes and into the concrete. You can get the needed depth using the depth gauge on the hammer drill.
Attach the Toilet Flange on the Concrete
Screw the toilet flange onto the concrete subfloor using Tapcon anchors or a related kind of concrete/masonry screws. If your flange ring is plastic, make sure not to screw the anchors too far in so the ring does not crack.
After installing your toilet flange, you can use a new wax ring for your toilet installation.