Chapter 16 (Product Knowledge) Flashcards
Lot Types
A property is characterized by many elements such as the structure’s architectural design, its roof style, and so forth. The shape of the lot is also an important feature of a property.
- Corner lots are bounded with streets on two sides. Commercial corner lots are generally worth more than interior lots. Residential corner lots are often desirable because of their “curb appeal”.
- Interior lots are bounded on each side by another lot.
- T-intersection lots are interior lots that suffer from their location at the end of a T intersection. They are usually less desirable because of the inconvenience of car headlights shining into the home and a possible danger from speeding “runaway” cars.
- Cul-de-sac lots occur when a street is open at one end only and it has a circular turnaround at the other end. Lots located on the cul-de-sac are desirable because they usually are more spacious, providing ample room for backyard features such as swimming pools.
Residential cul-de-sac lots also tend to have less vehicular traffic.
- Flag lots are characterized by a long access road or driveway back to the main part of the lot. The access road suggests the staff of a flag. Typically flag lots occur as a result of residential development in what once was a large homestead. The long access road usually increases the cost of bringing utilities to the lot.
- Key lots are generally long skinny lots similar to the shaft of a key that are often bounded by as many as five or six lots (see lot 6 below).
Note that the term key lot is also used to indicate a lot that has added value because of its strategic location.
Footer and Foundation
The footers and foundation provide support for the structure. The footer extends around the perimeter of the building to provide support for the structure and helps prevent the structure from settling. There are three basic styles of residential foundations.
Pier
A pier is a column of masonry. Four or more piers are used to support a structure. Piers lift the structure above ground level to allow a crawl space below the structure.
This type of foundation has the advantage of allowing easy access to plumbing and electrical connections as well as providing space to run ductwork.
Piers can raise the structure even higher if needed in coastal and other flood-prone areas.
Slab-on-Grade
Slab-on-grade construction involves pouring a concrete slab directly on the ground.
The slab is reinforced with steel rods and the ground is covered with a plastic, waterproof vapor barrier.
Slab-on-grade foundations are the most economical type of foundation.
Basement
Not many areas of Florida allow for basement construction because of the high water table.
Framing
There are three methods of wood-frame construction: platform, balloon, and post-and-beam. Platform framing is the most common construction method today.
However, balloon framing is common in older homes.
Post-and-beam construction is popular in contemporary architecture.
Platform
Each floor is built separately, with the first floor providing a work platform for the structure above.
This method of construction is safer for the framers because a flat surface is provided on which to work.
The subfloor extends to the outside edges of the structure and provides a platform on which exterior walls are erected.
Typically, the wall framing is assembled on the concrete slab and then hoisted into place and anchored.
If the house has more than one story, additional layers of floor platforms and walls are stacked on top of the first floor walls. The structure is completed with ceiling and roof framing.
Balloon
Balloon construction is used today for some two-story construction, especially if the structure has a masonry exterior.
With balloon frame construction the studs extend continuously to the ceiling of the second floor, providing a smooth unbroken wall surface at each floor level.
For example, in two-story construction, the load-bearing wall studs extend in one piece from the foundation to the top plate two stories above.
The continuous construction reduces uneven settling that can cause cracking of brick, stucco, and stone veneer finishes.
Balloon framing is a more expensive type of construction compared with platform construction because of the cost of quality 18- to 20-foot studs and higher labor costs.
Post-and-Beam
Sturdy posts support beams that are spaced up to 8 feet apart and covered with 2-inch planks that serve to form the floor, ceiling, and roof deck.
Because the posts provide some of the ceiling support, rooms can be constructed with larger spans between the supporting side walls.
This type of framing is popular in contemporary architecture where exposed beam ceilings are desired.
Masonry
In Florida, masonry construction is common. Masonry construction includes brick and concrete block construction.
Solid masonry walls are durable.
Masonry does not eliminate termite problems because most roofs are constructed with wood trusses.
Masonry walls reduce termite concerns.
The walls must be insulated.
Roof Structures
Most roof structures today use pre-engineered, factory-built trusses.
Trusses are lifted into place with a crane and then secured to the walls with metal fasteners.
Trusses are constructed with triangular-shaped internal structural members that transfer the stress load of the roof away from the center of the span outward to the load-bearing walls.
Roof pitch (slope) refers to the amount of height (rise) a roof has compared to the horizontal measurement (span or run) of the roof.
All roofs have some pitch. Even so-called flat roofs have a small indiscernible pitch to provide for water runoff.
A roof that rises four inches in height over a one-foot horizontal distance has a pitch of 4/12.
Homes are characterized by the style and pitch of the roof.
Roof styles include gable, hip, saltbox, shed, flat, gambrel, and mansard (see below).
Roof Types
- Gable roofs are cost effective because they use a single truss design.
Gable roofs peak at the center ridge and extend downward on two opposite sides.
Gable roofs do not provide protection from the sun on the two gable ends.
Sometimes dormers are incorporated into gable and hip roofs (see above).
A dormer is a projection that extends out of the roof to provide additional light and ventilation.
- Hip roofs peak at the center ridge but extend downward on four opposite sides.
Hip roofs provide overhang protection on all four sides of the structure and are architecturally pleasing.
Trusses for a hip roof are more expensive to manufacture because of the special engineering required.
- Saltbox roofs are characterized by what appears to be a gable roof that then slopes steeply on one side. It gets its name from the old Morton saltbox of the early 1900s.
- Shed roofs consist of a single steep plane. They are often used in contemporary architecture.
- Flat roofs are commonly called built-up roofs because of the way they are constructed in layers of tar and gravel. Flat roofs are used in contemporary residential structures as well as commercial structures.
- Gambrel roofs are characterized by the American barn style of roof. They provide ample headroom in two-story construction.
- Mansard roofs are named after a French architect who is credited with first using the style in Paris, France. Paris had a zoning code that prevented multistory structures because structures were being built higher than the fire equipment could reach. The zoning code defined the number of stories of a structure by the number of feet from ground level to where the roofing material began. Mansard cleverly brought the shingles down the walls of the top floor, thereby increasing the number of buildable stories without violating the zoning code. The mansard roof became very common in France and is used in French-style architecture in the U.S. Mansard roofs are very common in the French Quarter district of New Orleans, for example.
Electrical System
Lines carrying current to the house enter through wires strung overhead and attached to a post called a weather head or through an underground conduit.
In new construction, even in those subdivisions that are serviced by overhead power lines, the electric service lines from the transformer to the house run underground.
In older homes, electric service lines may go from a transformer attached to a power pole to the weather head. The energy is directed through a meter and then to the service panel inside the house.
Because electricity travels in a circuit (or a closed loop), there must be at least two wires entering the house—one hot wire (power is always present) and one neutral wire (the return path). Most homes built after 1950 have three wires running to the weather head—two lines each carrying 120 volts of current and a third grounded neutral wire. One hot wire and the neutral wire provide 120 volts for circuits suitable for lights and wall outlets. Both hot wires and the neutral wire provide 240 volts for large appliances such as air conditioners, electric ranges, and electric clothes dryers.
The utility company connects the incoming wires to a weatherproof box that holds the meter. The meter measures how much electricity the home uses.
Circuit breakers are used to protect an electric circuit from damage caused by too much current.
A breaker will trip (shut off) if the circuit is forced to carry more current than the wire can handle.
Inside the breaker is a tripping mechanism that will not allow the breaker to be reset until the wire has cooled.
The circuit breaker, once tripped, must be reset by hand.
In areas of the house where there is a greater danger of electrical shock (in kitchens and bathrooms), ground-fault-interrupters (GFIs) are required.
Electricity is distributed in a three-wire system; the hot, neutral, and ground wires. The hot wire carries the current to the switches, the neutral wire carries the current away (completes the loop), and the ground wire routes the excess electricity to the ground.
The size of the wire used in a circuit is based on how much current it will carry.
According to the American Wire Gauge (AWG) rating system, the smaller the number, the larger the wire.
The larger the load, the larger the wire needed.
For example, wire supplying power to wall switches may require #12-gauge wire, whereas wire used to supply a clothes dryer may use #8-gauge or #6-gauge wire.
Non-metallic sheathed cable used in residential wiring is identified by the number of wires in the cable.
For example, a cable stamped with the words 12/2 with ground indicates that the cable contains two #12-gauge wires and a ground wire.
The individual wires in the cable are color coded.
The hot wire is normally black.
If the cable has two hot wires, one is black and the other is typically red.
The neutral wire is either white or gray.
The ground wire can be green but is usually a noninsulated bare copper wire.
The black wire delivers power to the electrical switch and the white is the return path to complete the circuit.
Plumbing System
Residential plumbing systems are composed of two basic systems.
- The high-pressure system delivers potable water (suitable for drinking) to the various parts of a home.
- Low-pressure system carries wastewater away from the home.
Potable water typically enters the house through the water meter on the street side of the house.
The potable water is delivered under pressure.
The supply pipe has a main shutoff valve near the meter.
Opening and closing the main shutoff valve controls the water supply to the entire home.
The supply pipe carries water to the house from the municipal supply and then branches out into pipes of smaller diameter to deliver water throughout the home.
A cold water main carries water to the water heater and to all cold-water-using fixtures.
Hose bibs (exterior water faucets) run from the cold water line to locations on the exterior of the house.
A hot water main starts at the water heater and runs parallel to the cold water main, providing hot water to all hot-water-using fixtures.
The water heater is normally located in the garage area and has a pressure valve at the top of the tank that releases if the pressure inside the tank becomes too great, preventing a potential explosion.
Waste water, under normal atmospheric pressure, is drained off by gravity to main sewer lines.
There are two important components of the low-pressure system.
- Traps, which are beneath sinks, tubs, and showers, are typically U-shaped pipes that stay full of water.
The water forms a seal in the waste line and prevents odors and combustible gases from entering the home.
- Vent stacks are pipes that protrude through the roof from the waste lines.
The vent stacks equalize the air pressure in the drain system and prevent suction generated by flowing water from siphoning the water out of the traps.
Mechanical Systems
Mechanical components include air cooling and heating systems.
The most common type of heat distribution system is a forced air/ducted system that distributes warm air through ducts to each room of the house.
There are two sets of ducts.
- The supply air ducts carry the hot air from the furnace to the distribution registers throughout the house.
- The return air intake collects the cooled air through return ducts to a filter located in the furnace, where it is reheated and recycled throughout the home.
Older homes may have a gravity system that distributes heat and returns air throughout the system.
Today, ducted systems are equipped with a blower to force the flow of air throughout the home.
Heating cycles are rated by a heating seasonal performance factor (HSPF). The higher the rating, the more energy-efficient the heater is.
Air-conditioning systems are rated either in BTUs (British thermal units) or in tons. Twelve thousand BTUs are equivalent to a one-ton capacity.
The efficiency of electric air-conditioning systems is measured by a seasonal energy efficiency ratio (SEER).
National minimum standards for central air conditioners require a SEER of 13.
The higher the rating, the more energy-efficient the equipment is. Increasing the SEER from 10 to 13 means that you are increasing the equipment’s efficiency by about 30%.
A heat pump is equipped with a reversing valve that allows it to collect heat from cold outside air or from well water.
This reversing mechanism allows a heat pump to heat the home in the winter and cool it in the summer.
Heat pumps are very efficient in Florida, where winter temperatures are mild.
In the event of a cold snap, electric heating coils are activated when the outside temperature drops to about 25 degrees.
