Ch.11 Flashcards
From a firefighting standpoint the roofs of buildings can be classified into three styles ?
Flat
Pitched
Curved
Low slope roofs have a slope of up to ____ , meaning for each ____ units of horizontal dimension the roof slopes upward ___ units ?
3/12
12 units
3 units
Medium to high slope roofs have slopes of ____ to ____?
4/12 to 12/12
Some structures including churches and mansions have roofs with a slope of ____ or greater , too steep to work from a roof ladder?
18/12
__________ , ________ and aesthetic considerations determine the design of pitches roofs?
Climate
Function
The simplest pitched roof is the ______ roof that slopes in only one direction?
Shed roof
Common roof style that consists of two inclined surfaces that meet at their high side to form a “ridge” ?
Gable roofs
Style of roof that slopes in four directions and has a degree of slope similar to the gable roof?
Hip roof
Slope in two directions but there will be a break in the slope on each side , space under can be used as an attic or living space?
Gambrel roof
Has a break in the slope of the roof on all four sides ?
Mansard roof
Roof style that slopes in two directions , basically two shed roofs that meet at their low eaves ?
Butterfly roof
Roof Style designed to provide light and ventilation, once commonly used on factory buildings a raised central section of the roof extends several feet above the surrounding roof surface ?
Monitor roof
A style also once commonly used on industrial buildings for light and ventilation , ideally the glass vertical sections should face north because the northern light is more constant during the day and the glare of the sun can be avoided?
Sawtooth roofs
Modern ventilation and lighting systems have largely eliminated the need for _________ and __________ roofs ?
Monitor and sawtooth roofs
________ roofs are most frequently supported by arches and bowstring trusses?
Curved roofs
A dome can be thought of as an arch rotated _____ degrees on its top point ?
360 degrees
The structural forces of a ____ roof are similar to those of an arch?
Dome roof
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 as its center?
Lamella Arch
_________ are most commonly made of wood , and vary in thickness from 2x8 inches to 3x16 inches and in lengths varying from 8 to 14 feet ?
Lamellas
The short lamellas are bolted together in a diagonal pattern with a special plate known as a _____________?
Lamella washer
A ______________ is created using spherical triangulation?
Geodesic dome
A ________ is frequently provided in buildings with pitched roofs to increase the available living space in an attic?
Dormer
Horizontal structural members used to support a ceiling or floor ?
Joists
Flat roofs may be supported by _________ and steel beams ?
Open web Steel joists
The simplest system of flat roof support uses ordinary wood joists supported at either end by __________ walls?
Load bearing
Fireproofing can be omitted from roof supports when the roof is located more than ___ feet above the floor in an assembly occupancy?
20 feet
A variation of the flat roof is a type known as the _________ roof?
Inverted roof
Inverted roofs use __________ that differ from conventional roofs primarily in the location of their main roof beams?
Inverted trusses
Truss supported 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?
Inverted truss
Inclined beam that supports a roof , runs parallel to the slope of the roof , and to which the roof decking is attached?
Rafter
Horizontal roof framing member in the top third of framing system , braces the roof framing against the uplift of wind?
Collar tie
horizontal member in a pitched roof to which the upper ends of rafters attach ?
Ridge board
Horizontal roof framing member at the bottom of the roof framing system , helps keep walls from spreading due to the weight of the roof?
Rafter tie
Roofing system constructed on site , often uses dimensional lumber and nails /screws but can also use pre engineered components?
Conventionally framed roofs
From the outside , the inverted roof may look like like any other _______ roof?
Flat roof
If the architect desires to leave the underside of the roof exposed without joists , a structural _________ must be used to support the rafters?
Ridge beam
Wood _______ vary in size from 2x4inches to 2 x 14inches , they can be spaced from 12 to 24inches apart depending on the span of the roof?
Rafters
Truss structure with the chords and diagonal members arranged in parallel planes ?
Common truss
In lightweight wood trusses the individual members would be wooden 2x4 or 2x6 inches and individual trusses would be spaced ___ to ___ feet apart from center to center ?
2 to 4 feet
_________ trusses use split ring connections at all joints , except the heel plates located at the ends of the truss ?
Bowstring trusses
_____ and _____ trusses are the most common types used for pitches roofs?
Fink and Pratt
Roof covering made of flexible material that may be applied to the roof deck as a continuous sheet, commonly used on shallow pitch roofs?
Roll roofing
Horizontal member between trusses that support the roof?
Purlin
The deck of a roof is the portion of roof construction to which the roof covering or ___________ material is applied?
Roll roofing
___________ decking may have a thickness of 1/2 inch on supports , 24 inches on center ?
Wood panel
Wood planks will have a minimum ___ inch nominal thickness?
1 inch
Corrugated steel used in roof decking ranges from ___ gauge the thinnest to ___ gauge the thickest ?
29 gauge
12 gauge
Gypsum has the advantage of being __________?
Nailable
When cast in place concrete is used as a roof deck , the roof must be attachable to the deck, this attachment may be accommodated with wood nailing strips imbedded in the concrete at intervals of ___ feet?
3 feet
The __________ is designed to reduce the diffusion of interior moisture into the insulation layer , it is used in climates where significant temperature fluctuations are common?
Vapor barrier
The _______ insulation reduces heat loss through the roof?
Thermal
The three general categories of roofing membranes used are ?
Built up membranes
Single ply membranes
Fluid applied membranes
Built up roofing membranes roofing felt usually is supplied in rolls ____ feet wide, the number of layers of roofing felt varies but four layers is common design ?
3 feet
Built up roofs usually last for ____ years if the manufacturers specifications are followed ?
20 yrs
____________ membrane roof consist of a single membrane laid in sheets on the roof deck?
Single ply
Single ply membrane material comes in sheets ___ to ___ feet wide and up to ___ feet long, membranes are thin , typically 0.03 to 0.10 inches thick?
10 to 20 feet
200 feet
____________ membranes are useful for buildings with curved roof structures such as domes that would be difficult to cover with other materials?
Fluid applied
Asphalt shingles are available in several sizes but the most common size is ___ x ___ inches ?
12 x 36 inches
Built up roofs that use gravel as the best course are commonly known as _______________ roofs ?
Tar and gravel roofs
The __________ permits the free movement of rain water to the roof drains?
Drainage layer
The _______ protects the roof from the mechanical abrasion?
Wear course
__________ are thin , tapered slabs of wood that are sawn from pieces of a tree trunk?
Wood shingles
______ are manually or machine split from the wood and are thicker than shingles?
Shakes
What are the 3 types of wood , shingles and shakes are made from due to their resistance to decay?
Redwood
Red cedar
White cedar
________ are installed with an overlap so only 1/3 of the surface is actually exposed to the weather?
Wood shingles
______ ,______ and _______ tiles are non combustible and produce fire resistant roof coverings that have excellent resistance to flying brands?
Clay
Slate
Cement
Roofing Slate can be produced in sheets as thin as ___ inches although it may be as thick as ____ inches ?
1/16th inches
1 1/2 inches
Slate is a durable material and can have a life expectancy of ____ years ?
150 yrs
Slate is also heavy material , weighing __ to __ pounds per sq foot?
8 to 36lbs
Aluminum and steel sheets are ________ to increase the strength of the material?
Corrugated
__________ corrosion occurs when some types of dissimilar metals are in contact?
Galvanic
During NFPA 256 (fire tests of roof coverings ) testing , the individual test procedures may be repeated from ___ to ___ times on different samples depending on specific material being tested?
2 to 15 times
What are the 3 classifications for roof coverings?
Class A- severe fire exposure
Class B - moderate fire exposure
Class C - light fire exposure
Often the new _______ will have a steeper pitch than the original roof?
Rain roof
Term used to describe the incorporation of such environmental principles as energy efficiency and environmentally friendly building materials into design and construction?
Green design
Green design roofs may include reflective systems known as _________ and intentionally enhanced biodiversity known as ____________?
Cool roofs
Brown roofs
Energy sources that meet the needs of current consumers without compromising future resources ?
Clean energy
A single unit of solar energy collector is referred to as a _____?
A series of solar cells arranged are referred to a ________?
A system of solar panels is called an ______?
Cell
Panel
Array
A green roof , depending on the depth of the soil , the dead load can vary from ___ pounds per sq ft to ___ pounds per sq ft?
20 lbs
150lbs
Another primary hazard of vegetative roofs is the added ______ if the vegetation is not properly hydrated or if fertilizers are improperly stored ?
Fire load
__________ are small structures erected on the main roof of a building?
Penthouses
The primary purpose of a __________ is to provide natural lighting to the interior of a building?
Skylights
Building codes restrict the materials used in skylights to ________,________ or _____________?
Plastic
Wired glass
Tempered glass