Plumbing and Mechanical

Sanitation

For sanitation purposes, the minimum plumbing requirements for a residence include providing a kitchen sink, toilet, lavatory and a bathtub or shower.

All plumbing fixtures need to be connected to an approved water supply and a sanitary sewer or an approved private sewage disposal system. Additionally, bathroom, kitchen and laundry outlets must be supplied with hot and cold water.

Hot water shall be supplied by an approved automatic water heater or other type of domestic water-heating system sufficient to supply hot water to fixtures and appliances in spaces intended for bathing, washing or cooking.

Storage tanks for hot water heaters must be constructed of or lined with noncorrosive metal. And need to be connected and located where they can be maintained, serviced, and replaced.

Ideally, hot water heaters should be installed in a room with a floor drain, and should be equipped with a shut-off valve, to minimize damage in the event of a leak.

Bathrooms Requirements:

All bathroom fixtures shall be spaced according to Figure R307.1. Important dimensions are:

• The center line of the toilet or bidet must be at least 15” from a wall or other obstruction, and needs 21” of forward clearance.
• Sinks are shown in 4 different configurations- in all cases the sink should be 4” off the wall and have 21” of forward clearance. Double sinks should be separated by a minimum space of 4”. A sink next to a toilet also needs 4” separation space, but a sink next to a tub needs only 2” of separation.

The minimum dimensions allowed for a shower is 30” x 30” (that’s 900 square inches), and there should be a minimum of 24” forward clearance at all shower entrances. Plumbing fixtures, faucets, and fittings must have smooth impervious surfaces, free of defects, and constructed of approved materials. Fixtures must be provided with a supply of potable water adequate to flush the fixture and maintain a clean and sanitary condition, without danger of back flow or cross connection.

Shower Specifications:
In addition to the minimum area of interior space required for showers by Figure R307.1, there must also be 70” of minimum height provided above the shower drain.

Shower openings must have a clear and unobstructed finished width of not less than 22”, and hinged shower doors, if used, must open outward.

Shower valves and shower/tub combination valves must be equipped with pressure-balance controls, thermostatic mixing, or a combination of the two. They must also include a high limit stop, set to limit the water temperature to 120 degrees maximum.

Walls and floors in shower and tub spaces must be of a nonabsorbent surface material that extends at least 6 feet above the floor. Such material cannot be water-resistant gypsum board. Although water-resistant gypsum board is permitted for use as a backer for tiles or wall panels in showers and tubs, it cannot be installed over the vapor retarder, as this would create a waterproof membrane on both sides of the gypsum board, trapping moisture and ultimately causing it to fail. Ideally, gypsum board should not be used in wet areas.

Mechanical Ventilation Systems

Mechanical ventilation systems circulate fresh air using ducts and fans. Ventilation systems significantly improve a home’s air quality by removing allergens, pollutants and moisture that can cause mold problems. They can provide proper fresh air flow with appropriate locations for intake and exhaust and can also provide filtration, dehumidification and conditioning of the outside air as it enters. Without ventilation moisture, odors, and other pollutants can build up inside a home.

Venting:

Ducts are used in heating, ventilation, and air conditioning systems, to deliver and remove air. Air ducts are one method of ensuring acceptable indoor air quality, as well as, thermal comfort.

Outside air intake openings cannot be located within 10 feet of vents, chimneys, plumbing vents, streets, alleys, parking lots, or loading docks, as these are considered sources of hazardous or noxious contaminants. Exhaust from bathrooms and kitchens are not considered noxious or hazardous.

If a source of contaminant is located within 10 feet of intake openings the opening needs to be located at least 2 feet below the contaminant source. This will help prevent contaminants from being introduced into the ventilation system or exhaust from entering into occupied areas or into other buildings.

Exhaust openings located outdoors must not be directed on to walkways or create a nuisance by its location. Additionally, exhaust and intake openings that terminate outdoors should be protected from the weather with corrosion-resistant screens, louvers, or grilles with openings ¼” to ½” in any dimension.

Bathroom Exhaust:

Exhaust air from bathrooms and toilet rooms should not be recirculated within a residence or to another dwelling unit, but should instead be exhausted directly to the outdoors. This prevents the flow of contaminants from one unit to another.

Bathroom fans should not be vented into an attic or crawl space because it can cause moisture build-up, discoloration, and rot in the rafters. The humidity can damage the structure and insulation.

Exhaust fans should be located in or near the shower or tub, and in an enclosed water closet. Keep exhaust points opposite the supply air source to ensure that the fresh air is drawn through the room.

Bathroom doors should not be sealed too tightly at the bottom in order to allow “makeup air” to enter the room when the door is closed.

Ventilation fans in bathrooms should have the capacity to exhaust a minimum of 50 cubic feet per minute intermittently or 20 cubic feet per minute continuously.

Laundry Exhaust:

Clothes dryers emit high levels of moisture, which could lead to mold growth and building deterioration if vented to the indoors. Therefore, clothes dryers must be exhausted in accordance with the manufacturer’s instructions, be independent of all other systems, and convey any moisture and combustion products to the outside.

The exhaust should be terminated to the outside in accordance with the manufacturer’s installation instructions. In the absence of installation instructions, the exhaust duct cannot terminate less than 3 feet in any direction from openings into house. Screens should not be installed at the duct termination, but should instead be equipped with a backdraft damper, which is a damper with blades actuated by gravity, permitting air to pass through them in one direction only

Kitchen Specifications:

According to the Florida Building Code, a range hood is not required in a kitchen, unless an open-top broiler is installed. Domestic open-top broiler units must include a 28 gage metal exhaust hood. It should be installed with ¼ inch between the hood and the underside of combustible materials or cabinets. The cooking surface of the broiler unit needs a clearance of at least 24” from combustible materials or cabinets. The exhaust hood needs to be at least as wide as the broiler unit and extend over the entire unit. Additionally, it must exhaust to the outside and have a backdraft damper or other means to control infiltration and exfiltration when not in use. The ventilation rate required for kitchen exhaust is 100 cubic feet per minute intermittently or 25 cubic feet per minute continuously. All household cooking appliances must be listed, labeled and installed in accordance with the manufacturer’s installation instructions.

Fuel-fired appliances:

Gas-fired appliances such as stoves, ranges, heaters and lamps require special consideration. A supply of air for fuel combustion and ventilation of the space in which the appliance is installed must be provided. Failure to supply adequate air can result in improper draft, soot production, increased carbon monoxide production, and risk of fire or explosion; failure to vent properly can cause build-up of carbon monoxide, high temperatures, and increased risk of fire.

Fuel-fired appliances may not be located in bedrooms, bathrooms, or storage closets. They can however, be located in spaces that can only be accessed from and open into such rooms, but only if all combustion air is obtained from the outdoors through permanent openings with a solid weather-stripped door and self-closing device. This is to avoid build-up of combustion gases, or the depletion of oxygen levels. Asphyxiation can result from inadequate combustion air.