11- Building Construction- Roofs Flashcards
Several fundamental safety points regarding roofs include:
-Roofs are usually not as strong as floors (designed to support lighter live loads)
-Many types of roof construction have inherent concealed spaces (between ceiling and roof deck)
-Over time, loads may be added to roofs for which they were not originally designed
From a fire fighting standpoint, the roofs of buildings can be classified into three styles:
Flat, Pitched, Curved
____ Roofs are the easiest roofs on which firefighters can work.
Flat
Low slope roofs have a slope of up to _/12, meaning for each 12 units of horizontal dimension the roof slopes upward _ units.
Medium to high slop roofs have slopes of _/12 to _/12.
Low - 3
Medium to High - 4/12 to 12/12
____ Roofs- Common roof style that consists of two inclined surfaces that meet at their high side to form a “ridge”
Gable
____ Roofs- Style that slopes in four directions and has a degree of slope similar to the gable roof
Hip
____ Roofs- Slope in two directions, but there will be a break in the slope on each side. The space under these roofs can be used as an attic or living space.
Gambrel
____ Roof- Has a break in the slope of the roof on all four sides. Forms a projection beyond the building wall that creates a concealed space through which fire can travel.
Mansard
____ Roof- Roof style that slopes in two directions; basically two shed roods that meet at their low eaves.
Butterfly
____ 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. The vertical sides of this section, which are normally openable windows, are known as “clerestories”.
Monitor
____ Roofs- A style 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
Curved roofs are most frequently supported by ____ and ____ _____.
Arches and Bowstring Trusses
A ______ is frequently provided in buildings with pitched roofs to increase the available living space in an attic.
Dormer
______ Framed Roofs use inclined members to support some types of pitched roofs that are built on site utilizing dimensional lumber.
Conventionally
Conventional roof framing components include:
-Rafters
-Ridge Boards
-Collar Ties
-Ceiling Joists and Rafter Ties