Tips from CAA-Quebec - Low-flush toiletsDo you still have some concerns about the ineffectiveness or unreliability of low-flush toilets? The following information should reassure you. There has been plenty of water under the bridge since the first eco-toilets appeared in the early 1980s.

Good intentions
At the time, devising a new type of toilet seemed like a good idea. With each flush, traditional models used 12 or even 18 litres of water – treated drinking water, no less!

But many people were disappointed by the performance of the first low-flush toilets (using six litres of water) or double-flush toilets (three litres for liquid waste, six litres for solids). The main criticisms were fouling or blockages in the trap or supply line and blockages in the drain pipes.

A revised design
These problems had to be dealt with. Most residential toilets work by gravity (with the water flowing from the tank to the bowl before being sucked into the drain pipe by a siphoning effect). Manufacturers then had the idea of greatly increasing the diameter of the opening between the tank and the bowl and widening the trap at the bottom of the bowl. The result is a more powerful flow, providing better cleaning of the bowl and more effective evacuation.

The industry has also introduced high-performance 4.5-litre and 4.8-litre models equipped with a simplified mechanism. André Dupuis of the Corporation des maîtres mécaniciens en tuyauterie du Québec sees this as an excellent compromise between six-litre models (which use more water) and mechanically complex double-flush models.

Proven efficiency
How can you be sure to get a toilet that works effectively? Since 2003, more than two-thirds of the toilet models on the market, including water-efficient toilets, have been evaluated by an independent body that measures the quantity of solid waste they can evacuate with a single flush. Their performance is published in the report of the Maximum Performance Testing of Popular Toilet Models (MaP) program.

You can also depend on labels under the U.S. Environmental Protection Agency’s WaterSense program, guaranteeing that the toilet will evacuate at least 350 grams of waste per flush. Given that an average of 150 grams of waste has to be flushed with each use, any toilet providing this capacity should be quite adequate for most people’s needs.

Watch out!
One minor hitch: installing a low-flush toilet could be a mistake in a basement with old drain pipes. The smaller volume of water, combined with a lack of height and low angles in sewers, may lead to blockage if sediments or rust have accumulated in the pipes or if the backup valve is worn out. This should be taken into account.

Other important elements in buying a toilet

  • Quality of the porcelain: The quality and thickness of the glazing applied to the toilet are what will give you ease of maintenance and a long-lasting look. The length of the guarantee on the finish and the manufacturer’s reputation are the best indicators of quality. 
  • Availability of spare parts: Go for a CSA-certified plumbing fixture from a reputable manufacturer. Avoid uncertified imported products, which can be found for sale in Quebec even though their installation is not authorized!
  • Insulation inside the tank: This is essential to prevent occasional wetness caused by condensation (when the water is very cold but the surrounding air is warm and humid).
  • Traps (the opening at the bottom of the bowl lined up at the floor flange with the drainage pipes): The distance between the wall and the middle of the trap is an important consideration both when conducting the renovation work and when buying the toilet. The standard distance is 12 inches, but some toilets are designed for distances of 10 or 14 inches. At least one American manufacturer offers a toilet with a plastic trap of 10, 12 or 14 inches.
  • Round or elongated bowls: Models with elongated bowls are preferable for comfort but are not always suited for tight spaces.
  • Height of the bowl: To help elderly people get up easily from the toilet, there may be a temptation to install a raised bowl. However, for most people, this raised position is quite different from the most natural bodily position for using the toilet. Installing a well-adjusted grab bar will often be more useful than a high bowl, though a high bowl may be appropriate for someone with reduced mobility or who is very tall.
Tips from CAA-Quebec - Water-efficient Toilet

To conclude
When replacing a standard toilet, remember that its use accounts for nearly one-third of a house’s water consumption. A single high-efficiency ecological toilet can save thousands upon thousands of litres of this blue gold each year without your having to alter your normal living habits!

We thank André Dupuis of the Corporation des maîtres mécaniciens en tuyauterie du Québec (CMMTQ) for his contribution to this advice capsule.
Additional source: Canada Mortgage and Housing Corporation (CMHC).