Chapter 11 Flashcards
3 Fundamental safety points
Roofs are usually not as strong as floor because they are typically designed to support lighter live loads
Many types of roof construction have inherent concealed spaced between the ceiling and the roof deck making it difficult to determine the extent to which a fire has developed over head
Over time loads may be added to roofs for which they were not originally designed
Low Slope roofs have a slope up to
3/12
Medium to high slop roofs have a slope up to
4/12 to 12/12
slopes of 18/12 or greater too steep to work from roof ladder is when a fire fighter should think about using
aerial apparatus
Clerestories are
The vertical sides of this monitor section which are normally openable windows
arched roof structure composed of a series of intersection skewed arches made up of relatively short straight members two members are bolted riveted or welded to a third peace at its center
Lamella Arch
what is created using spherical triangulations that is triangles are arranged in three dimensions to for a nearly spherical surface
Geodesic domes
Geodesic dome can be constructed with materials indluding
Wood
Steel
Concrete
plywood
bamboo
aluminum
what roof is it when the main joists are located at the level of the ceiling and the framework is constructed above the main joist to support the roof deck
Inverted roof
4 conventional framing components of roofs are
Rafters
Ridge boards
Collar ties
Ceiling joist and rafter ties
the 5 most common roof types constructed with conventional framing include
Shed
Gable
Hip
Gambrel
Mansard
conventional roof framing is constructed using substantial materials fasteners common to this type of roof structure include 3
Nails and screws at connection points
heavy bolts or brackets in heavy timber construction
architectural hardware for exposed beams
Supports are often substantial with ridge beam
Typically one size larger than the rafter
Wood Rafters vary in size from
2x4 to 2x14 and can be spaced 12 to 24 inches apart
Wooden trusses sizes are
2x4 or 2x6 spaced 2 to 4 feet apart center to center
the top chord tries to straighten out and the bottom chord maintains the shape of the shape of the top chord through tension is wat kind of truss
Bowstring truss
Two most common types of trusses used for pitched roof is
Fink and Pratt Trusses
The Difference between Fink and Pratt truss is
Pratt has a king post in the center while the Fink does not
Wood panel decking may have a thickness of
1/2 inch supported 24 inches on center
Wood planks will have a minimum thickness
1 inch thickness
Corrugated steel used in decking rages from _____ thinnest to _______ the thickest
29gauge
12 gauge
Corrugated steel used in decking depth ranges
From 3/4 to 2 inches
Vapor Barrier
Is designed to reduce the diffusion of interior moisture into the insulation layer
3 General categories of roof membranes
Built up membranes
Single ply membranes
Fluid applied membranes
