Toilet Rough in Requirements

Rough-In Requirement

• The term “rough-in” refers to a measurement used to determine where the toilet needs to be placed in relationship to the wall behind the toilet, the floor and the flange opening on the floor so the toilet connects correctly with the plumbing work. The rough-in measurement describes the distance from a finished wall or floor to the center of the drain where waste is flushed from the toilet.

Standard Rough-In

• The standard rough-in requirement for most toilet brands and models is 12 inches. This means that the toilet is designed to connect and work with a drainpipe on the floor that is 12 inches from the wall. When the proper toilet is installed, the center point of the toilet drain spout will match correctly with the plumbing work.

Other Sizes

• While the 12-inch rough-in is most common, there are also toilets made with and for 10-inch and 14-inch sizes. This means that instead of requiring a distance of 12 inches from the wall, the toilet will work with a plumbing pipe work opening that is spaced out 10 or 14 inches from the wall.

Replacing an Older Toilet

• If you are replacing an older toilet with a new one, measure the existing rough-in placement. This will eliminate errors in purchasing the wrong size toilet. Open the seat and notice where the center of the drain is located. Measure out from the wall to the center location. This measurement will tell you whether you need to focus on toilets with a 10, 12 or 14-inch rough-in. In most municipalities, you need a permit to replace the toilet yourself because toilets connect to municipal water work and sewage systems, and your self-installation may still require a final inspection by local building code officials. Check first before you purchase a toilet or attempt any work on your own.

New Constructions

• When you install a new toilet in a new home or building, don’t skip ahead and purchase a toilet just because it’s on sale or you like the design without knowing what the rough-in requirements are to work with your plumbing system. If you are picking out the toilet yourself, find out the rough-in specifications by asking your general contractor and the lead plumbing contractor. This ensures you know whether you need a toilet that fits 10, 12 or 14-inch rough-in specifications.

Alterations and Retrofitting

• If you’re replacing an old toilet and you’re dead set on a model that does not match your existing rough-in requirements, be prepared for additional costs. Your plumbing will require modification to meet that 2-inch or 4-inch difference, going from a 12-inch to a 10-inch rough-in or from a 14-inch to a 10-inch rough-in. Focus on models that work with your plumbing, and not the other way around. As a general rule, if it doesn’t fit, don’t force it.