When one sees or hears the words "wall-hung toilet," images of the fixtures used for public restrooms in airports, stadiums and shopping malls across North America come to mind.
While commercial installations have been the major market for wall-hung toilets in North America for many years; in Europe they have been installed in residential applications as well as public facilities for more than 35 years.
How does a residential wall-hung toilet differ from those that are common to the North American market? The most noticeable difference is the method of flushing the bowl.
While North American public toilets are flushed by flushometer valves requiring large diameter supply pipe, the residential toilets use a concealed tank and carrier system utilizing gravity flush and 1/2-inch nominal water supply.
Typical commercial wall-hung toilets also make use of a cast-iron, self-supporting carrier system while the residential models use a wall-supported, steel-frame system with an integral-flushing tank.
The concealed tank-and-carrier with wall-hung toilet bowl accounts for about 70 percent market share with floor-mounted toilets being the minority installation in the core European countries.
Why would someone install a wall-hung toilet in a residential application? The major reasons are ease of sanitation; rim height adjustability and space savings.
It is very easy to clean around and under a bowl that does not have a base firmly attached to the floor. The concealed tank and carrier system allows rim heights that range from 15 inches to 19 inches with the same unit. No need to have a standard bowl, a "chair height" bowl and an ADA- height bowl, since one unit does it all.
Since the tank is mounted in the wall, there is a considerable space savings that can be achieved compared to a floor-mounted bowl with a tank on the back. This can amount to as much as 9 inches of additional space in a bathroom. This is a bonus in small powder rooms or in large master bathrooms where spaciousness is a deciding factor in the design.
In the late 1950s and into the 1960s, several manufacturers made wall-hung toilets with tanks that used the same cast-iron carrier system used by commercial toilets. These installations were very common in high-rise condominiums. When the flush volume regulations started to dial down the amount of water used, they were abandoned as they could not be made to flush on 1.6-gallon (6L) and they also fell out of favor from a decorator point of view.
Current wall-hung toilets have several different flushing systems depending on manufacturer. The first method is gravity based wash-down. These bowls come from Europe and are modified to meet minimum water surface dimensions dictated by codes.
Recently, gravity siphonic has been developed and provides the consumer with a more familiar flushing style since the majority of toilets sold in the North American market are siphonic. It has the same rim wash, refill cycle and sounds that North Americans have come to associate with their toilet.
The manufacturers who gave up on wall-hung bowls with an exposed tank were given the opportunity to bring them back to the market with the advent of the pressure assist or flushometer tank toilet flushing system. This air-assisted method provides better flushing characteristics than most gravity toilets and will operate very well on the 1.6-gallon (6L) code requirement.
One manufacturer has taken the pressure-assist flushing method and moved it all back into the wall and combines it with the wall supported carrier system. This gives the unit the benefits of the wall-hung bowl, the flushing system benefits of pressure-assist and the space-saving characteristics of a concealed tank & carrier toilet.
One of the most common questions regarding wall-hung residential toilets is "How do I vent it?" If an installation is using a self-supporting cast-iron carrier, it is vented through the carrier. This method is very familiar to any commercial plumber.
The concealed tank and carrier systems, whether gravity or pressure-assisted type, vent in the same manner as a floor mounted toilet. Local and national codes will guide the installer through the venting process. A picture of a typical venting installation is shown on the next page.
Another question, can the wall-hung bowl support the user? The same code requirement for commercial wall-hung bowls is applied to the residential models. As long as the wall is well built, the product is capable of supporting the weight of the user.
When using a wall-supported concealed tank and carrier, the wall must be 2 x 6 construction and depending on the unit used, either 16 inches on center or an opening of 19 3/4 inches is required. If metal studs are used, it is recommended to supplement the support by using the cross members and boxing in the location of the tank & carrier using 2 x 6 framing lumber.
Probably the most common question when someone is reviewing the concealed tank-and-carrier with wall-hung toilet system is "What happens when I have to fix it?" After 35 years in the European market, this question is the easiest to answer. All of the flushing mechanical parts inside the tank are accessible and can be removed through the opening on the front of the unit that is covered by the flush-activator panel.
The only time tools are used is to shut the water off (a screwdriver) and to remove the water supply line feeding the fill valve (a wrench). After that, everything comes out of the tank without using tools.
The story of the wall-hung residential toilets in North America is just beginning. Residential architects and custom home designers are recognizing the value and design capabilities of the product for the luxury and near-luxury market. This is the same market that first adopted the one-piece toilet 15 years ago. As everyone knows, the market for the one-piece has now entered the mid-price housing range. The same can be expected of wall-hung residential toilets in the years to come.
