How to Spec Toilets

Printer-friendly versionSend by email

Water conservation and drought make a good toilet a must have. The water supply system is under significant stress. Reservoirs and aquifers have limited capacity and are difficult to expand due to the cost and fragile ecosystems.

April 01, 2008

Water conservation and drought make a good toilet a must have

The water supply system is under significant stress. Reservoirs and aquifers have limited capacity and are difficult to expand due to the cost and fragile ecosystems. Meanwhile, severe drought has expanded from the west (where it is a permanent condition) to the southeast. As temperatures rise and population swells, no region will be exempt from water shortages.

Conservation is the first line of defense against shortages, but it's also the prime directive in green building. What can a remodeler do? Spec a good toilet, because 30–40 percent of residential water is flushed down the drain.

The toilet market is divided into low-flow units rated at 1.28–1.6 gallons per flush (gpf) and high-efficiency toilets using less than 1.28 gpf. To earn EPA's WaterSense label, a toilet must use less than 1.28 gpf and clear at least 350 grams from the bowl. (After 2013, this will be the statewide standard in California.) However, the flushmark continues to drop. LEED for Homes grants 2 credits for toilets using 1.1 gpf or less.

Some plumbers worry that high-efficiency toilets don't generate enough hydraulic push to clear drainlines. Don't fret. Studies indicate they meet or exceed the waste carry requirements — even without supplemental flow from showers, baths, or washers.

Here's a better arena for anxiety: Price isn't indicative of toilet quality. Furthermore, all high-efficiency toilets and WaterSense toilets — toilets the EPA labels as water-efficient — are not created equal. When overloaded, some toilets back up. Others routinely require two or more flushes to clear the bowl. You want a loo that flushes with the least amount of water.

Several years ago, the California Urban Water Conservation Council launched the Maximum Performance program to evaluate toilets. The protocol require researchers to flush toilet paper plus sausages of soybean paste, beginning with 250 grams and moving up in 50 gram increments until it takes a second flush to clear the bowl. Poor performers fail the 250 grams threshold, while the best whoosh down 1,000 grams. (The latter is overkill, because 99.5 percent of waste is less than 350 grams.)

Supplemental Links: 

Two Sides of the Leak Issue

John Koeller, the Conservation Council's toilet expert says, "Our studies have shown that toilet leaks are really nowhere near as much of a problem as they were 10 years ago." Why? Older toilets had a ball cock fill valve. With increased nighttime pressure in the municipal system, water slipped down the overflow tube. "This problem has been largely eliminated with the advent of the pilot valve in most gravity-fed toilets today."

But Terry Love, a Bellevue, Wash., plumber who has installed thousands of toilets, says some are more prone to leaks than others — and all will eventually leak, unless homeowners replace flappers and seals every five years or so. To prevent this, he suggests including a toilet section in the homeowner's maintenance manual — and be sure to spec the right parts.

Toilet technology is more complex than one might imagine, ranging from gravity-fed models that dominate the market to pressure-assist, dual flush and flushometers. Love prefers gravity-fed models, the easiest to repair.

AQUS System

Coming down the pipeline

Typically, greywater systems reuse water from sinks, showers, dishwashers and washing machines — but not toilets. However, toilet tanks are an ideal receptacle for greywater. Sinkpositive replaces the lid of an ordinary toilet with a small sink that drains into the toilet. The AQUS System, shown at right, places a holding tank under an existing sink and then pumps discharge to the toilet tank. The Brac System is a whole house approach, recycling water from showers, tubs, and washing machines to toilets.

As water supply problems worsen, composting toilets — which are very different in smell and mode of operation from the outhouse — may become as common in the U.S. as they are in Scandanavia, where the limitation is topsoil for leach fields.


If you have ideas or comments, e-mail the author at Click Here

Comments on: "How to Spec Toilets"

September 2015

This Month in Professional Remodeler


See which projects were the real standouts among this year's wealth of entries, and be inspired

Overlay Init