Years ago, I learned a lesson that you can’t have a flush valve tailpiece trap primer on an ADA water closet because it raises the height of the flush valve and causes a conflict with the ADA grab bar. This was back in the day when manual flush valves were the norm.

Today, of course, sensor operated flush valves are the norm for commercial installations – either battery operated or hard wired. Meanwhile, the criteria for ADA water closets has changed – or at least the enforcement of it has.

The height requirement for ADA grab bars is 33 to 36 inches measured from the floor to the top of the grab bar, not the centerline. The grab bar is 2 inches in diameter and has a requirement of 1-1/2-inch clearance all around. This is where the fun begins.

For some reason I have been specifying (and my company has been installing) ADA sensor operated water closet flush valves and no problems have arisen - unless there was a physical conflict with the grab bar. As of late, projects have ADA specialists who check clearances for all the ADA elements before project closeout – another niche industry adding complexity, cost, and frustration to the construction process. On one recent project all of the ADA flush valves had a fractional interference with the grab bar clearance ranging between 1/8 and ¾ inch. All of the ADA flush valves had to be replaced with a shorter model to resolve the issue. It was a complete waste of money.

If you add up the dimensions, the typical wall mounted ADA water closet is installed with the rim at 16-1/2 inches, and floor mounted ADA water closets are also 16-1/2 inches tall to ensure that the seat is at least 17 inches above the floor – the ADA minimum.

Of the sensor operated flush valves I have researched, Sloan’s product is 16-1/2 inches tall, American Standard’s is 16-1/8 inches tall, and Zurn’s is 16-3/8 inches tall. The Toto product lists no dimension to the top of the valve, but it has an installation note about mounting the grab bar at the maximum 36 inches or using a split grab bar for ADA installations. I would bet my paycheck that the valve interferes with the 1-1/2-inch clearance requirement at the grab bar.

Even with the shortest valve of those mentioned, adding the 16-1/8 inches plus the 16-1/2 inches fixture height gives you 32-5/8 inches. Looking at the grab bar, 36 inches less the 2-inch diameter and 1-1/2-inch clearance gives you 32-1/2 inches. So in a perfect world, even the shortest sensor flush valve I could find has a 1/8-inch clearance conflict with the ADA.

There is a solution to this issue. If you specify a retrofit style flush valve such as the Sloan Optima Plus or the Zurn AquaSense the valve will be no taller than a manual flush valve. But, it is frustrating having to specify a retrofit style flush valve for a new installation.

I am not naming particular manufacturers to slander any one of them – I am merely pointing out that this is an industry wide issue. In today’s age with barrier busters gone wild, all of the new sensor operated (non retrofit style) flush valves need to be less than 16 inches tall to meet ADA requirements. Realistically, they need to be about 15-1/2 inches tall to allow for field tolerances, and none of them are so designed.

The ADA does have an allowance for interruption of the grab bar – creating a two-piece grab bar – for installation of the flush valve controls. If you ask the manufacturer that is the solution: to interrupt the grab bar. But of course the architect and general contractor will not want to do this for both aesthetic and financial reasons. Plus, it’s just plain silly, to interrupt a grab bar where no physical conflict exists. That would only make sense for a bedpan washer flush valve installation that is tall and creates a physical conflict.

I have appealed to local ADA specialists, asking the question of the difference between the interruption of the clearance and the interruption of the grab bar itself. What’s the difference? If the ADA allows for interruption of the grab bar, why is the interruption of the clearance any different? But of course my logic falls upon deaf ears. Rules is rules. And there is no elegant solution.

To make matters worse, if your project has LEED point requirements that weigh heavily on water conservation, the use of 1.1 GPF water closets is of great benefit. The only manufacturer of 1.1 GPF toilets and flush valves that I am aware of is American Standard. However, that flush valve does not meet the clearance requirements dictated by the grab bar – it is 1/8 inch too tall - so you cannot use it for ADA installations. This is the very same flush valve we had to remove on a recent project due to clearance conflicts. None of the retrofit style flush valves that meet the ADA clearance requirements have a 1.1 GPF option, so the dilemma gets further complicated.

I am hoping that the industry will soon respond by producing flush valves that are 15-1/2 inches tall to resolve this issue. I realize that product redesign is costly, but so too is the price of removing and replacing new product to satisfy the petty nuances of the ADA.

Timothy Allinson is vice president of Engineering at Murray Co., Mechanical Contractors, in Long Beach, Calif. He holds a BSME from Tufts University and an MBA from New York University. He is a professional engineer licensed in both mechanical and fire protection engineering in various states, and is a LEED accredited professional. Allinson is a past-president of ASPE, both the New York and Orange County chapters. He can be reached at lagunatictim@gmail.com.