Toilet Setting Supplies

Setting a toilet comes down to four parts working together, and most leaks and wobbles trace back to getting one of them wrong. A toilet seal is a gasket that sits between the toilet base and the flange on the floor, with its main purpose being to create a watertight seal that keeps water and sewer gasses from leaking out of the connection between the toilet and the drainpipe. The flange anchors the bowl to the subfloor. Bolts hold it steady. Shims kill the rocking. Get the seal-to-flange-height match right and the toilet lasts decades. Get it wrong and you’re chasing a leak that rots the subfloor underneath.

For broader project planning, explore WBC’s building materials resources.

Here’s the part that confuses most people. Generally wax doesn’t “go bad” on a standard floor-mounted toilet, as its function is not to prevent leaks — wax on a floor-mounted toilet is there to prevent odors. If you are experiencing a leak coming from underneath a floor-mounted toilet, you probably have a partial or full-blown toilet stoppage — or a cracked bowl. Replacing the wax ring three times won’t fix a clog.

Wax Ring vs. Wax-Free Seal

This is the real buying decision. Both create the seal. They behave differently in the truck, on the floor, and on a reset.

Wax has the track record. Wax rings have been used for over a century, are made from a blend of petroleum waxes, and are designed to be soft and malleable, allowing them to conform to the shape of the flange and toilet base. They seal well and cost less. The downsides matter in Montana. Once compressed, a wax ring cannot be reused if you need to reposition the toilet, and wax rings can become hard and less effective in cold temperatures. For the best installation results, make sure the wax ring is at room temperature — to speed that up, place the ring in warm water for a few minutes to soften the wax.

That cold-temperature behavior is worth flagging for anyone setting a toilet in an unheated cabin or a seasonal place that’s been sitting cold. A wax ring pulled out of a cold truck won’t conform right.

Wax-free seals — rubber or PVC — solve the temperature and reset problems. Unlike wax rings, rubber gaskets can be repositioned without losing their sealing capability and are less affected by temperature fluctuations. The Fernco PVC seal is the one to know. It accommodates floors raised above the toilet flange by up to 3/4”, maintains a gas tight seal even when minor movement occurs, and comes in FTS-3 for 3” flanges and FTS-4 for 4” flanges. It eliminates the need for flange risers or stacked wax rings and is resistant to mold and mildew. One more advantage for radiant-heat floors: it’s ideal for in-floor radiant heat systems since it will not melt like wax rings are prone to do.

The Korky wax-free kit takes a foam approach. Its rubber exterior creates a tight seal between the toilet and floor, while its two-piece foam interior adapts to flanges above, even with, or below finished floors, and it can be repositioned during installation — unlike wax rings, which must be replaced if the toilet isn’t set correctly on the first try. The 6000 kit includes the gasket, two bolts, metal and plastic washers, two nuts, and instructions.

The tradeoffs are honest. Non-wax gaskets are generally more expensive, some can degrade when exposed to certain cleaning chemicals, and while newer non-wax gaskets perform well initially, their long-term durability is not as well-documented as wax rings.

One hard rule on wall-hung toilets: skip the wax. Wax does not have “memory,” and over time all walls will flex somewhat — when that happens, gravity allows a space that allows leaks. Wax gaskets are great for regular toilets but not for wall-hung toilets.

Seal type	Best for	Reusable	Cold behavior
Standard wax ring	Flange flush with floor, one-time set	No, single-use	Hardens; warm before setting
Extra-thick / jumbo wax	Slightly recessed flange	No	Hardens; warm before setting
Rubber/PVC wax-free	Resets, radiant heat, raised floors	Yes	Won’t melt or freeze
Foam wax-free	Uneven floors, varying flange height	Yes	Resistant to hot and cold

Matching the Fix to Your Flange Height

Most install headaches come from flange height — usually after new flooring raised the floor above the flange, or a flange that sits too low. Get the flange position right first. Match the flange material to your pipe and ensure the top sits flush with or up to 1/4 inch above the finished floor.

For a flange that sits flush, a standard wax ring does the job. For one that’s slightly recessed, go thicker — the extra-thick wax gaskets are built for exactly this. Fluidmaster’s 7513 is one example: it fits 3” and 4” waste lines, carries 40% more wax for tall flooring, and uses a polyethylene flange for easy install.

For a flange that sits too low, this is where people make the worst mistake. Don’t stack wax rings. If the flange is too low, use stackable flange spacers or extenders, but avoid stacking wax rings. Stacked wax has no structure and no memory — it’s a leak waiting to happen. Use PVC spacers with silicone between the layers instead. And if you need a tall stack of spacers, that’s a sign the flange should be reset properly rather than shimmed up with layer after layer.

The wax-free route sidesteps the whole problem when the floor is raised. The Fernco seal’s long neck handles up to 3/4” of raised floor without any risers or stacking. Match the pipe size before you buy — common waste lines are 3” and 4”, and flanges fit into or over those sizes.

For broken flanges, you don’t always have to cut one out. A spanner-style repair flange eliminates the need to replace a broken closet flange — you place the flange under the broken area of the ring and tighten the nut. Split-ring and solid-ring repair flanges cover the same problem.

Western Building Center’s setting-supply lineup covers the range: standard and no-seep wax gaskets, an extra-thick wax ring with flange, Fernco FTS-3 and FTS-4 wax-free seals, a wax-free gasket, flange spacers and a wax ring extender kit, PVC closet flanges in 3” and 4” including an offset flange and a twist-and-set type, plus split-ring and solid-ring repair flanges for fixing broken ones.

Stopping the Wobble and Setting It Right

A rocking toilet cracks porcelain and breaks the seal. Shim it — with the right material. Use plastic or composite shims to stabilize a wobbling toilet; never use wood, which rots. That matters double in Montana, where moisture under a toilet base will turn a wood shim to mush. The plastic stabilizer shims run 2” long by 1-1/8” wide and stack. Insert shims into the gaps and trim the excess. Don’t over-shim — lifting the base too far breaks contact with the seal.

On bolts, brass beats steel because steel rusts and seizes. The setting sequence keeps you from cracking the bowl.

• Press the new wax ring firmly onto the toilet horn, align the closet bolts, and lower the toilet straight down.
• Sit on the toilet to compress the wax, then hand-tighten the nuts — do not overtighten.
• Dry-fit first to check bolt alignment before adding the wax, so you don’t waste a single-use ring on a misaligned set.
• Scrape all the old wax off the flange and horn before resetting.

If you’re using wax-free, the reset advantage is real on a remodel. The wax-free seal lets you pull and reset a toilet numerous times without fail while a bathroom remodel is underway, and the toilet can be removed and re-installed with the same seal attached.

Frequently Asked Questions

My toilet still leaks after replacing the wax ring twice. What’s wrong? Probably not the wax. On a standard floor-mounted toilet, the wax prevents odors, not leaks. A leak coming from underneath usually means a partial or full toilet stoppage. A cracked bowl is the other common cause. Replacing wax over and over won’t solve either one.

Can I stack two wax rings if my flange sits too low? No. Use stackable PVC flange spacers or extenders instead, with silicone between layers. Avoid stacking wax rings. If you’d need more than about three spacers, reset the flange properly rather than building a tall stack.

What size do I need — 3 inch or 4 inch? Match the waste line. Seals and flanges come in 3” versions for 3” drain pipe and 4” versions for 4” pipe. Measure before you buy.

Is wax-free worth the extra cost? For a one-time set on a flush flange, a wax ring does fine. For a remodel where you’ll pull and reset the toilet, a cold or unheated install, a raised floor, or radiant heat, wax-free earns it. Rubber gaskets can be repositioned without losing sealing capability and are less affected by temperature fluctuations.

Why not wood shims — they’re cheaper? Wood rots. Use plastic or composite shims; never wood. Under a toilet base, with the moisture that collects there, a wood shim won’t last.

Should I use the wax ring straight out of a cold truck? No. Wax rings become hard and less effective in cold temperatures, so make sure the ring is at room temperature for best results. Warming it in warm water for a few minutes softens the wax. This is the wax-free seal’s biggest edge in cold-climate installs.