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Ask the Builder: Become a porcelain throne expert

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Few homeowners get to see the underside of a toilet. That brown wax ring creates a water- and gas-proof seal between the toilet and drain pipes. The wax seal can last for over one hundred years.

In these turbulent financial times, I want to share as much of my accumulated knowledge with you as possible. In this column space, I’m going to try to save you money each and every week.

This week we're going to talk about the toilet, a fixture shrouded in mystery to many homeowners and even to experienced DIYers.

I’ve been a master plumber since 1981, and I can tell you that while toilets appear complex, they’re usually quite simple. Once you understand the way the average toilet incorporates physics, you’ll soon be able to tackle any and all repairs yourself. What’s more, with my help, you can even remove and install a new toilet by yourself in less than an hour, if that’s what you want to do! I’ve got step-by-step instructions how to do this at

Let’s start with the toilet bowl. When you flip up the toilet seat cover, you should see a standing pool of water. That water is sitting in a U-shaped trap no different than the u-shaped pipe under your sinks, tubs and showers. You only see half of the water. The other half is in the bowl colon. This colon passageway curls up and then down again creating the pathway to the drain pipe.

This water in the bowl serves two purposes. First and foremost it provides a barrier for sewer gas and vermin from entering your home. Without this water, foul-smelling sewer gas would waft into your home much like smoke rises off a burning stick of incense. Vermin need to be excellent deep-dive swimmers to make if from the hidden side of the trap to the room side that you see when you peer down into the bowl.

The water spot is supposed to make it easier for the toilet bowl to stay clean when solid waste is deposited into the bowl. Years ago, when the first-generation 1.6-gallon-per-flush toilets were introduced, many had a smaller water spot. Customer complaints got rid of this design quickly.

The toilet bowl must connect to the drainage pipe under the floor so gas and water don’t leak into your home. For many decades this was done using a wax gasket. For the gasket to produce a seal there needs to be about a 3/8-inch gap between the top of the toilet flange and the underside of the toilet china. The flange is a special fitting that is attached to the top of the drain pipe. The toilet bolts to this flange.

Too small of a gap between the toilet and the flange can squeeze too much wax out and too much of a gap means the wax doesn’t make a perfect seal between the toilet and the flange.

Your toilet flushes away waste using simple physics. Remember that easy formula in high school? Force equals mass times acceleration. The force of the flush is created by the mass of water that accelerates as it travels from the tank down into the bowl. Gravity helps do this in your home. In most commercial toilets, this force is created by the water pressure in the water supply line. My guess is you’ve never really thought much about the absence of a toilet tank in most commercial restrooms.

Older toilets did a better job of flushing and carrying the waste to the city sewer or septic tank because they had more mass. Old toilets typically had twice the amount of water flow into the bowl than modern toilets. Very old toilets had the tanks up about six feet in the air. Those really flushed well because the water had more hydrostatic head.

The two moving parts inside your toilet tank are the things that flummox most homeowners. You just have a fill valve and a flapper valve. The fill valve allows fresh water to fill the tank after you flush. The flapper valve stops the tank water from flowing into the bowl after the tank fills with new water.

You can adjust the fill valve so that you get the maximum amount of water flowing into the toilet bowl with each flush. To do this, you adjust the float on the fill valve to stop the flow of water just as the level in the tank rises to the top of the overflow tube. This tube is a drain pipe that prevents water from overflowing the toilet tank should the fill valve malfunction and not shut off. Can you imagine the flood in your home if you walked out of the bathroom and water started to overflow the tank? Oh my!

Worn-out flapper valves create phantom flushers. Have you ever heard your toilet tank start to briefly refill when no one has used the toilet? You might think a ghost flushed the toilet! The cause is simple. A small amount of water seeping past the flapper valve causes the level of the water to drop in the tank over a period of a few minutes. As the fill valve float drops, it eventually triggers fresh water to enter the tank.

You can test for these small leaks by using food coloring. Clean your toilet bowl well and then flush the toilet. Once the fill valve stops the water from entering the tank, wait about 30 seconds. Squirt a generous amount of green food coloring into the tank water. Come back into the bathroom an hour later to see if the color of the water in the bowl is a light shade of green. If so, it’s time to replace the flapper valve.

The internet is overflowing with helpful videos showing you how to install new fill valves and flapper valves. It’s extremely easy, and as long as you can turn off the shut-off valve that supplies water to your toilet tank, you can do these repairs with a few common tools.

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Are you trying to save money in these harsh financial times? Have you given up trying to find a contractor, and are you starting to do more projects on your own? If so, you’ re in fine company, as my email inbox has exploded over the past months with requests for help.

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