Handheld Shower Spray ADA Requirement for Non-Positive Shutoff
For bathtub and shower installations in Title III commercial building installations, such as a hotel, a non-positive shutoff valve feature is required when a detachable shower spray head is installed in a room designed for use by individuals with disabilities. And, according to the Americans with Disabilities Act (ADA), shower spray units are required in bathing rooms designed for use by individuals with disabilities. The photo on the right is representative of a shower spray unit where there is a fixed/main shower head shown on the right and a detachable shower spray unit head on the left.
2010 ADA Standard 607.6, [Bathtubs] Shower Spray Unit and Water, states, “A shower spray unit with a hose 59 inches (1500 mm) long minimum that can be used both as a fixed-position shower head and as a hand-held shower shall be provided. The shower spray unit shall have an ON/OFF control with a non-positive shut-off.” The same requirement exists for shower compartments in 2010 ADA Standard 608.6.
In other words, a bathtub or shower for a disabled individual has to have a shower spray head that has an ON/OFF switch and a non-positive shutoff, but what is a non-positive shutoff and why is it required? The answer lies in the requirement for a 59 inch hose for the shower spray unit.
A common installation has a hose for the main head and a hose for the detachable head connected at a diverter valve that is attached near the faucet. The photo on the left is representative. Note that this installation is about 16 inches above the floor of the bathtub. Note also that in this installation the faucet, main shower head, and shower spray head, all share the same main shutoff valve faucet handle. The diverter valve is used to make the water flow go from the faucet to the main shower head and the detachable spray head, and vice versa. An ON/OFF switch at the detachable shower head controls the water flow there.
The issue is that when the detachable spray shower head with the 59 inch hose is detached, it can be dropped or laid down into the tub or shower floor, where it could be under water that has been used for cleaning. This water is sometimes referred to as brown water. The plumbing code does not allow brown water to be pulled back into clean [potable] water, so there has to be safeguards to prevent this back flow. Potable water, also known as drinking water, is treated to levels that meet state and federal standards for consumption.
For these installations, a non-positive shutoff within the detachable spray shower head allows for a small flow of clean/potable water through the detachable spray shower head even when the ON/OFF switch for the detachable head is in the OFF position. In other words, OFF is never completely off so that there is a flow of water out of the spray head, which prevents the back flow of brown water into the detachable head.
SUMMARY: A non-positive shutoff valve feature is required when a detachable shower spray head is installed in a bathing room designed for use by individuals with disabilities. A non-positive shutoff within the detachable spray shower head allows for a small flow of clean/potable water through the detachable spray shower head even when the ON/OFF switch for the detachable head is in the OFF position. This flow of water prevents the backflow of brown water into the plumbing system.
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