How to Install a Toilet Flange Extender

First, ensure the toilet is removed and the water supply is off. Wear disposable gloves. Use a putty knife to scrape off all of the old wax from the top of the existing toilet flange. It's crucial to remove all residue to ensure a clean surface. Use rags to wipe the flange and the surrounding floor area clean. To prevent foul-smelling sewer gas from entering the room and to stop tools or debris from falling into the drain, stuff a large rag securely into the drain pipe opening.

Before applying any sealant, perform a dry fit. Place the toilet flange extender ring directly on top of the clean, existing flange. Check to see that it sits perfectly flat on the flange and the surrounding floor without rocking. Verify that the slots for the closet bolts on the extender align correctly with the slots on the original flange. This ensures that when you set the toilet, the bolts will pass through both the extender and the original flange correctly.

After confirming the fit, remove the extender ring. Using a caulking gun, apply a continuous, generous bead of 100% silicone caulk onto the top surface of the original flange. The bead should be about 1/4-inch to 3/8-inch thick. It is critical to apply the caulk on the flange surface, inside the ring of screw holes, to create a complete, uninterrupted seal that will prevent water and sewer gas from escaping between the old flange and the new extender.

Immediately after applying the sealant, carefully place the flange extender onto the silicone bead. Press down firmly and evenly to spread the silicone and create a tight bond. Align the closet bolt slots of the extender with the slots on the old flange. Insert the new, longer closet bolts (often included with the extender kit) through the aligned slots. Slide them into the narrow part of the slot to hold them upright. Next, secure the extender to the subfloor. Drive the provided corrosion-resistant screws through the countersunk holes in the extender and firmly into the wood subfloor using a drill or screwdriver. Do not overtighten the screws, as this could crack the extender.

With the extender firmly in place, it's time to install the toilet. First, and most importantly, REMOVE the rag you placed in the drain pipe. Place a new wax ring onto the flange extender. You can either place it directly on the flange, centered over the opening, or press it onto the bottom outlet (the 'horn') of the toilet itself. Many plumbers prefer placing it on the toilet. Carefully lift the toilet, keeping it level, and position it over the two closet bolts. Lower the toilet straight down onto the flange extender, using the bolts as guides. Press down on the toilet bowl with firm, even pressure to compress the wax ring and create the final seal. You can sit on the toilet (with the lid closed) to help set it properly.

Place the plastic friction washers and metal washers, followed by the nuts, onto the closet bolts. Hand-tighten the nuts first. Then, use an adjustable wrench or deep socket to slowly tighten them, alternating from the left side to the right side a half-turn at a time. This ensures even pressure and prevents cracking the toilet base. Tighten until the toilet is stable and does not rock, but do not overtighten. The porcelain can easily crack. If the bolts are too long, use a mini-hacksaw to cut them down to just above the nut. Place the decorative plastic caps over the nuts. Finally, reconnect the water supply line to the toilet tank fill valve. Turn the water shutoff valve on slowly, allowing the tank to fill. Flush the toilet 3-4 times and meticulously check around the base of the toilet for any signs of water leaks.