Chapter 11 Flashcards
Lamella Arch
Arched roof structure composed of a series of intersecting, skewed arches, made up of relatively short, straight members; two members are bolted, riveted, or welded to a third piece at its center.
Joists
Horizontal structural members used to support a ceiling or floor. Drywall materials are nailed or screwed to the ceiling joists, and the subfloor is nailed or screwed to the floor joists.
Inverted Truss
Truss support system that is constructed with a deep triangular portion projecting down instead of up, and the portions of a standard truss are under compression instead of tension.
Conventionally Framed Roofs
Roofing system constructed on site; often uses dimensional lumber and nails/screws but can also use preengineered components.
Rafter
Inclined beam that supports a roof, runs parallel to the slope of the roof, and to which the roof decking is attached.
Ridge Board
Highest horizontal member in a pitched roof to which the upper ends of the rafters attach. Also known as Ridgepole
Collar Tie
Horizontal roof framing member in the top third of the framing system; braces the roof framing against the uplift of wind.
Rafter Tie
Horizontal roof framing member at the bottom of th roof framing system; helps keep walls from spreading due to the weight of the roof.
Common Truss
Truss structure with the chords and diagonal members arranged in parallel planes. Also known as Monoplane Truss.
Roll Roofing
Roof covering made of flexible material that may be applied to the roof as a deck continuous sheet. Commonly used on shallow pitch roofs.
Purlin
Horizontal member between trusses that support the roof.
Nailability
Property of a material that allows it to accept a fastener, such as a nail. Nailable materials include wood, gypsum, and some thin metals.
Green Design
Term used to describe the incorporation of such environmental principles as energy efficiency and environmentally friendly building materials into design and construction.
Photovoltaic (PV) System
An arrangement of components that convey electrical power to an energy system by converting solar energy into direct current (DC) electricity
Clean Energy
Energy sources that meet the needs of current consumers without compromising future resources. Also known as Sustainable Energy.
Green Roof
Roof of a building that is partially or completely covered with vegetation and a growing medium, planted over waterproof roofing elements. Term can also indicate the presence of green design technology including photvoltaic systems and reflective surfaces.
Gable roof
Common roof style that consists of two incline surfaces meet at their high side to form a ridge
Hip roof
Style that slopes in four directions and has a degree of slope similar to the gable roof
Gambrel roofs
Slope in two directions, but there will be a break in the slope on each side. The space under gambrel roof can be used as an attic or living space
Mansard roof
Has a break in the slope of the roof on all four sides. A mansard roof constructed with a flat deck is sometimes known as a modern mansard or deck roof. The mansard style roof forms a projection beyond the building wall that creates a concealed space through which a fire can travel.
Butterfly roof
Roof style that slopes in two directions basically two shed roofs that meet at their low eaves
Monitor roof
Style designed to provide light and ventilation. Monitor roofs were once commonly used on factory buildings. A raised central section of the roof extends several feet above the surrounding roof surface. The vertical sides of this monitor section, which are normally open of all windows are known as clerestories
Sawtooth roof
A style also once commonly used on industrial buildings for lights and ventilation. Ideally the glass vertical section should face north because the northern light is more consistent during the day and the glare of the sun can be avoided.
The most common roof types constructed with conventional framing include
She’d Gable Hip Gambrel Mansard
The vapor barrier is designed to
Reduce the diffusion of interior moisture into the insulation layer
The thermal insulation reduces
Heat loss through the roof. The insulation should have resistance to mechanical damage such as gouging, moisture decay, and fire
The membrane used under a roof consist of
Waterproof material that keeps out rain and snow from the interior of the building
Built up membranes
Built up membranes use several overlapping layers of roofing felt saturated with bituminous material that may be either tar or asphalt . The roofing felt usually is supplied in rolls 3 feet wide. The number of layers of roofing felt used varies, but four layers is a common design
Single ply membrane
The membrane material comes in sheets 10 or 20 feet wide and up to 200 feet long. The membrane are thin typically 0.03 to 0.10 inches thick. The most common is a synthetic rubber material, ethylene propylene diene monomer (EPDM) Single ply materials can be stretched and consequently will accommodate shifting in a building
Fluid applied membrane
Fluid applied membrane are useful for buildings with curved roof surfaces such as domes that would be difficult to cover with other materials
Wear course
The wear course protects the roof from mechanical abrasion.
NFPA 256
Standard methods of fire tests of roof coverings. Also designated ASTM E-108
Six separate test procedures
Intermittent flame exposure test Burning brand test Flying brand test Rain test Weathering test Spread of flame test
Class A roof covering
Are effective against a severe fire exposure
Class B roof covering are
Effective against a moderate fire exposure
Class C roof coverings are
Effective against a light fire exposure
Wood panel decking may have a thickness of
1/2 inch on supports 24 inches on center
Wood planks will have a minimum
1 inch nominal thickness
