Week 10: Chapter 6- Plumbing Systems

Chapter 6

Plumbing Systems 

In Chapter 5 we learned to Design efficient bathrooms and kitchens by stacking and grouping plumbing on common walls. Prepare plans with adequate clearances for plumbing,  Understand the basic components of water supply and waste disposal in a building, and Understand sustainability concerns as related to plumbing systems. 

Overview of How Plumbing Works

Plumbing systems consist of two primary parts: supply and waste. Supply water enters a building under pressure. This pressure allows the water to reach the upper levels of a building for use. At the entry to the building there is a main water shut-off valve with additional locational shut-offs at each fixture for minor repairs and maintenance. 

The Drain-Waste-Vent (DWV) part of the system relies on gravity and water's ability to seek its own level. Wastewater is divided into either black water (potentially containing human waste) or gray water (from sinks, laundry, and bathing). 

Gray water can be further divided into light and dark gray. Light-gray wastewater originates from bathroom sinks, bathtubs, and showers, while dark-gray wastewater comes from kitchen sinks and dishwashers and may contain grease or food particles.

Supply Options

The three primary water supply options include municipal water, provided by means of a water main; private well water; and rainwater harvested water. Most wells tap into the saturated ground beneath the water table. When a well extends through a non-permeable layer of earth into the aquifer, it is known as an artesian well. Rainwater catchment refers to the active collection of rainwater. Rainwater can be collected in two ways: through the use of a cistern or rain barrels. Rainwater needs additional processing to become a potable water source.

• Potable water is water that is suitable for drinking.
• Black water is wastewater that contains sewage.
• Gray water is wastewater from sinks, bathtubs, and washing machines.

Plumbing Systems

Plumbing refers to the introduction and elimination of water and human by-products to and from a building. Indoor plumbing is a relatively new phenomenon in the history of buildings. Whereas some residences featured indoor privies, outhouses were common well into the nineteenth century and, in some parts of the country, into the twentieth century. In some rural locations outhouses are still in use today in the United States. 

Plumbing systems are divided into water supply and wastewater. Water supply systems operate under pressure, while waste systems operate by gravity, thus requiring a slope in waste pipes.

Several issues impact water sustainability including a growing population, aging infrastructure (old supply and waste pipes which may be cast iron), poor water quality, reserved water rights, and groundwater overdraft. Further, sewer overflow being combined with storm water surges during a storm can lead to raw sewage contamination of water supplies.

Fixtures and Water Conservation

In an effort to reduce the amount of potable water being discharged into the waste stream, several items have been introduced into the market for use in buildings. Residential water use in the United States is broken down as shown in the Table. 

High-efficiency Toilets

As the single biggest source of interior water use, the toilet has been targeted for reduced use of water in general and potable water specifically. EPA’s WaterSense program means that certified toilets are 20 percent more efficient than other products. High-Efficiency Toilets (HETs) are defined as those using less than 1.28 gallons per flush (gpf). Recent building codes have outlined the use of more efficient plumbing fixtures of all types.

Low-flow Toilets

Recent legislation has required that new water closets use less water than those of the past. All major manufacturers now provide low-flow toilets.

Dual-flushing Toilets

Some toilets are equipped with a dual flushing mechanism that allows the toilet to be flushed according to its usage. When less water is required, one flush is used, versus two flushes when more water is required.

Waterless Urinals

Waterless urinals do not require water to operate and thus provide extensive water savings; however, they have been criticized for releasing odors into the restroom.

Low-water Urinals

These urinals are designed to reduce water usage by 85 percent.

Automatic Faucets

Automatic faucets are commonly used in commercial projects. A motion sensor turns the water on when hands are sensed beneath it. Following a specific period of time, the faucet shuts off the water flow.

Gray Water Re-use

Water from the sink, shower, and bathtub can be re-used to flush the water closet (toilet). The use of gray water is regulated from state to state. As of this writing, 26 states in the US have statutes in place regulating the use of gray water in buildings. When used, these sources must be clearly marked with signage, indicating that the water is not for drinking, as well as by the use of purple piping to distinguish it as a non-potable source.

Light-powered Faucets

Several manufacturers have developed faucets that use light to power the automatic sensors with no electricity required.

Low-flow Shower Heads

Low-flow shower heads reduce the amount of water used during a shower.

Tankless Water Heater

A tankless water heater heats water on demand and does not store water. Using a heat source, water is heated as it is needed near the location of use.

Composting Toilet

In rural locations where a municipal water supply and sewer facility are not available, composting toilets can be used. The composting toilet does not use water to operate. Waste is treated and over time decomposes into usable compost.

The Energy Policy Act of 1992 first introduced the need for reduced water usage in plumbing fixtures. Since then, the 2012 (updated every three years, most recently in 2018) International Green Construction Code (IGCC) outlined further water use reduction.

Impacts on Interior Design

The location of plumbing lines within a building have an impact on the space planning and interior design of a space. Although just about anything can be done, good design requires an interior designer to understand the limitations of what is practical and economical.

How to Place Plumbing Fixtures

Generally speaking, the fewer plumbing walls, the better the solution. A shared chase wall lessens the need for multiple 6-inch or thicker walls. Additionally, this saves on the amount of supply pipe and waste pipe, and multiple fixtures can then share the vent pipe to the roof. For all of these reasons, shared plumbing walls contribute to good design.

Clearances Required and Recommended

The building code provides minimum clearances for water closets and urinals. It is important to keep in mind that minimum clearances may not equate to comfort. As Americans get larger, a wider spacing from adjacent walls is preferable to provide a more comfortable experience. The building code also requires the number of fixtures within a space, depending on the use and occupancy

Stacking of Plumbing

In addition to placing all plumbing close together within a floor level, it is also preferable to stack plumbing from floor to floor. This way supply pipes, waste pipes, and vents can all be shared from floor to floor.

Chase Walls

When a wall is thickened to accommodate plumbing, it is called a chase wall. Chase walls often run from floor to floor in large buildings and can be shared by stacked fixtures.

Slope of Waste Pipes

When placing bathroom fixtures, it is important to keep in mind the required slope of waste pipes, which must fit within the floor thickness.

Traps

All bathroom fixtures must include a trap. The trap prevents sewer gases from backing up into the occupied interior space. Water must be held in the trap for this to work.

Air Gaps

The air gap in a supply line prevents contamination of the potable water supply by sanitary drainage systems.

Ventilation

An important consideration in bathroom design is ventilation. This can be achieved in one of two ways--through the use of a window to allow for natural ventilation, or mechanically using a ceiling- or wall-mounted ventilation fan. Introducing air movement into the space helps to remove odors as well as reduce the likelihood of mold.

Accessible Bathrooms

In public projects, a certain percentage of the bathroom fixtures must be Americans with Disabilities Act (ADA) compliant. This law impacts the height of water closets and lavatories, the inclusion of grab bars, the size of some bathroom stalls, and the type of faucets and accessories used within a bathroom (and kitchen). American National Standards Institute (ANSI) A117.1 (2009) added the requirement for a vertical grab bar in public accessible toilet locations and is referenced in the 2012 IBC.

Individual Bathrooms

In recent years, the push for individual bathrooms which are gender neutral has become common. The 2018 International Plumbing Code has updated signage requirements for single-user restrooms. According to the 2018 IPC, “Single user toilet facilities and bathing rooms. And family or assisted-use toilet and bathing rooms shall be identified for use by either sex.” (Section 403.1.2) The State of California as well as several major US cities (New York, Chicago, Washington D.C., Denver, Austin, Seattle, etc.) have enacted ordinances in support of all gender signage.

Other Plumbing Concerns

In addition to plumbing fixtures, designers must also be aware of sprinkler heads within the interior space. While specialists design the sprinkler systems for buildings, designers must integrate the placement of sprinkler heads with lighting and other ceiling-mounted items. Access to sprinkler plumbing must also be provided. A later chapter on regulations discusses sprinkler-head types.

Blogging Assignment

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The two things I noticed the most in these designs are the skinks, showers, and the placement of the grab bars. The sinks all have no cabinet underneath them. But they still found ways to cover up the plumbing or make the plumbing look nice. the showers are all even with the floor. There is no bump going into the shower. They also all have seats in the shower. Some were free-standing and some were even folded up onto the wall. This was helpful to see all of the different options when designing an ADA bathroom. The placement of the Grab bars was also very helpful to see. I never know exactly where to put them so to see examples is really helpful!