What is a toilet?

What this means for your home project

1. Measure from the toilet’s floor bolts to the wall behind it and record the rough-in for the replacement discussion. Source: Portland Water Bureau, read 2026-11-06.
2. Compare the proposed toilet base with the existing footprint; ask for a written scope stating whether exposed flooring needs patching or tile replacement. Source: Portland Water Bureau, read 2026-11-06.
3. Once a year, put a couple of food-coloring drops or a dye tablet in the toilet tank and wait ten minutes to test for a silent leak. Source: U.S. Environmental Protection Agency, read 2026-11-06.
4. Flush the toilet after the dye test so the dye does not stain the tank. Source: U.S. Environmental Protection Agency, read 2026-11-06.

What are the different types of toilets?

Home tank toilets include gravity, pressure-assist and electromechanical hydraulic designs. EPA describes gravity toilets as "found in most homes" and distinguishes single-flush models from dual-flush models: dual-flush controls offer a full flush for solids and a reduced flush for liquids (read 2026-11-06). (source)

“Varieties of tank-type toilets include: the standard gravity type (found in most homes); pressure-assist (or flushometer-tank toilets); and electromechanical hydraulic toilets.” (source) “Tank-type toilets are available as single-flush models or dual-flush models, which include a full flush for solids and a reduced flush for liquids.” (source)

What is a toilet rough-in?

Toilet rough-in measures the distance from the floor-anchoring bolts to the wall behind the fixture. Portland Water Bureau gives an average of "12 inches in most homes"; compare that measurement when selecting a replacement, rather than treating bowl height as the fit measurement (read 2026-11-06). (source)

“Rough-in is the distance from the flange bolts (the bolts that anchor your toilet to the floor) to the wall behind your toilet.” (source) “The average rough-in is 12 inches in most homes.” (source)

How tall is a toilet?

Toilet bowl height excludes the seat. Portland Water Bureau describes the typical American bowl height as "about 15 inches" and contrasts older toilets with taller comfort models around 18 inches. Compare the floor-to-rim measurement when considering a different height (read 2026-11-06). (source)

“Bowl height is the distance from the floor to the top rim of the bowl, not including the toilet seat.” (source) “The typical height for American toilets is about 15 inches.” (source) “However, many people choose to replace their older toilets with ADA or "comfort" models with a height of about 18 inches.” (source)

How do I check for a toilet leak?

Toilet tank leaks can be silent. EPA recommends a yearly food-coloring or dye-tablet test, "waiting 10 minutes" before looking for color in the bowl. Color entering the bowl indicates a leak that may involve a worn rubber flapper; flush afterward to prevent staining (read 2026-11-06). (source)

“Check for silent leaks at least once a year by putting a couple drops of food coloring or a dye tablet into the tank at the back of the toilet and waiting 10 minutes.” (source) “If the color shows up in the bowl, you have a leak that can probably be fixed by replacing the rubber flapper in the tank, which may be worn out.” (source) “Don’t forget to flush afterwards to avoid staining the inside of the tank.” (source)

What can cause a toilet leak?

Toilet leaks often involve the tank mechanisms. NYC DEP identifies "the flapper or fill valve" as the two most common causes. A warped or damaged flapper can prevent the watertight seal on the flush valve, so a leaking tank does not by itself identify the failed part (read 2026-11-06). (source)

“The two most common causes of a toilet leak are the flapper or fill valve.” (source) “Flappers can become warped or damaged over time, preventing a watertight seal on the flush valve.” (source)

How do I repair a toilet leak?

Toilet repair starts with the symptom: EPA recommends replacing worn flappers "at least once every five years" and investigating constant running, failure to flush or continuous flow into the overflow tube. EPA points homeowners to further troubleshooting resources or a plumber for those problems (read 2026-11-06). (source)

“Since toilet flappers wear out, replace them at least once every five years to ensure a good seal and avoid leaks.” (source) “If your toilet is constantly running, if it won’t flush, if you lift the tank lid and see water continuously flowing into the overflow tube within it, or if you detect any other toilet problem, investigate further with help from videos and other resources on WaterSense’s Fix a Leak Week web page or contact your local plumber to help.” (source)

How do I choose a toilet?

Toilet selection includes water use and flushing performance. EPA describes designs using "1.28 gallons per flush or less" and says WaterSense evaluates both performance and efficiency. EPA’s residential page identifies WaterSense Specification Version 1.2 as currently in effect; use that specification context when comparing labels (read 2026-11-06). (source)

“Design improvements have allowed toilets to use 1.28 gallons per flush or less while still providing equal or superior performance.” (source) “WaterSense labeled toilets are independently certified to meet EPA's criteria for both performance and efficiency.” (source) “On June 2, 2014, EPA released a revised version of the WaterSense Specification for Tank–Type Toilets (Version 1.2).” (source) “Version 1.2 of the specification is currently in effect.” (source)

What factors affect the cost of toilet replacement?

Toilet replacement can involve floor work as well as the fixture. Portland Water Bureau defines footprint as the area under the toilet and warns that choosing a smaller base may mean having to "patch the floor or replace some tiles". Ask whether that floor work belongs in the scope (read 2026-11-06). (source)

“Footprint is the area the bottom of your toilet covers on the floor.” (source) “If a smaller footprint is chosen, you might have to patch the floor or replace some tiles.” (source)

Sources

• How to find and fix a toilet leak — Portland Water Bureau; read 2026-11-06.
• Residential Toilets — U.S. Environmental Protection Agency; read 2026-11-06.
• Home Maintenance — U.S. Environmental Protection Agency; read 2026-11-06.
• Toilet Leak Detection — New York City Department of Environmental Protection; read 2026-11-06.
• WaterSense at Work: Toilets (Water Closets), May 2023 — U.S. Environmental Protection Agency; published 2023-05; read 2026-11-06.