Enhanced Fujita scale damage indicators and degrees of damage, chapter 32

A truss-like, lightweight, rigid structure constructed from interlocking struts in a geometric pattern. It is often used to span large areas with few interior supports.

'Built Up Roof' covering is a continuous, semi-flexible membrane consisting of plies of saturated felts, coated felts, fabric or mats assembled with alternate layers of bitumen and surfaced with mineral aggregate, bituminous material or granule surface sheets.

A pronounced high wall with a band of windows along the top. It usually rises above an adjoining roof.

'Concrete Masonry Unit' walls are forms of portland cement and aggregates made to various shapes, typically 20 cm high by 40 cm wide. CMUs can be either normal or heavy weight for load-bearing conditions. Light weight units are intended for non load-bearing conditions such as veneers.

Degree of Damage

'Exterior Insulation and Finish Systems' are multi-layered exterior wall systems built for commercial and residential buildings. EIFS consists of insulation board secured to the exterior wall surface by adhesive or mechanical attachment. There is a water-resistant base coat applied on top of the insulation and reinforced with fiberglass mesh. There is a finish coat applied to the exterior.

'Expected' value for 3-second gust wind speed at 10 m in flat, uniform, open terrain

A wood frame floor system consisting of joists, sheathing overlaid on joists, rim joists. Studs below provide a load path to the rim joists. Building codes may only require floor diaphragms to be fastened along continuously supported panel edges, often called an unblocked diaphragm. A fully blocked diaphragm means that each panel segment edge not on a joist is supported by a block.

A roof having two sloping sides that come together at a ridge, creating end walls with a triangular extension, called a gable, at the top

 

A secondary horizontal structural member attached to sidewall or endwall columns to which a wall covering may be attached.

A roof that slopes back from all four sides to a single point, or line, at the top

Heating, Ventilation and Air-Conditioning

'Insulating Concrete Forms' are used with poured concrete to produce permanent walls. Forms are made of foam insulation and a steel frame. Concrete occupies the interior of the form. ICF panels are connected with plastic ties.

'Lower Bound' value for 3-second gust wind speed at 10 m in flat, uniform, open terrain

A type of hip roof where each sloping section is divided in two to create maximum space under the roof; the first section near the walls rises steeply while the second section continues at a milder pitch toward the center.

A structural system designed to bear loads with a minimum of mass. It consists of structural wood top and bottom chords or steel tube webs with interconnecting pins.

'Oriented Strand Board', similar to plywood but uniform and cheaper, is a manufactured 2.4 m by 1.2 m wood panel made up of 2-5 cm long wood chips and glue.

A low wall or railing along the edge of a platform, terrace or roof.

Roof decking is sprayed with an elastic, closed-cell foam and then covered with an additional coating. The final cover is 5-10 cm thick.

A gypsum concrete roof deck consisting of gypsum concrete that is mixed with either wood fibers or mineral aggregate.

Channel-shaped steel structures used to span roof trusses of metal buildings and serve to support the roof deck. Common Purlins come in 'Z' and 'C' shapes.

Consists of a single waterproof membrane laid on a roof deck and attached by mechanical or adhesive fastenings. The membrane edge is tucked inside a metal perimeter flashing.

Composed of preformed or field formed pans, usually 45-60 cm wide. These pans run parallel to the roof and are joined to adjacent pans with double-locked standing seams. The seams have cleats 30 cm apart which locks the panels on the deck. Metal (e.g., copper) roofing may exhibit this type of construction.

A prefabricated concrete wall panel, often containing openings for windows and doors, that is hoisted into place by a crane or other mechanism. The roof diaphragm acts as a connector between the panels. However, the panels typically are not connected to each other to allow for expansion and contraction.

'Upper Bound' value for 3-second gust wind speed at 10 m in flat, uniform, open terrain