Building Construction Flashcards
Roof Decks
- Can be plywood, wood planks, corrugated steel, precast gypsum or concrete planks
- Wood panel: 1/2” on supports 24” on center
- Wood planks: Minimum 1” nominal thickness
- Corrugated steel: 29 gauge (thinnest) to 12 gauge (thickest); Depth ranges from 3/4-2”
- Gypsum: Nailable
Civil engineering
- Water supply
- Sanitary sewers
- Surveying
- Site prep and excavation
- Roadways
- Storm water drainage
Structural engineering
- Determination of loads
- Foundation design
- Structural behavior
- Structural members
- Structural erection
Mechanical engineering
- HVAC
- Pumping systems
- Elevators
- Plumbings systems
Electrical engineering
- Lighting
- Power
- Communications
Fire protection engineering
- Automatic sprinklers
- Standpipes
- Fire alarm
- Smoke control
- Code compliance
Type IIIA is required to have a ___ fire resistive rating for interior members
1 hour
- Note: Type III B has no fire resistive rating for interior members
Columns
- Support an axial load
- Stresses are primarily compressive
- Not designed to withstand stresses due to bending
- Tall, thin columns fail by buckling
- Short, squatty columns fail by crushing
Smoke developed rating
- Measure of the relative visual obscurity created by the smoke from tested material
Axial load
- Load applied to center of the cross-section of a structural member and perpendicular to that cross section
- Can be compressive or tensile
- Creates uniform stresses acros the cross-section of the material
Eccentric Load
- Load that is perpendicular to the cross section of the structural member but does pass through the center of the cross section
- Creates stresses that vary across the cross section
- May be both tensile and compressive
Torsional load
- Offset from the center of the cross section of the structural member and at an angle to or in the same plane as the cross section
- Produces twisting effect that creates sheer stresses in a material
Tension
- Tends to pull a material apart
Compression
- Tends to squeeze the material
Shear
- Tend to slide one plane of a material past an adjacent plane
NFPA 90A Standard for the Installation of Air-Conditioning and Ventilation Systems
- 1 hour - Buildings less than 4 stories
- 2 hour - Building 4 stories or greater
Transformers
- 3 hour enclosure if not protected by sprinklers
- 1 hour enclosure if protected by sprinklers
Footing
- Widened base at the bottom of a column or foundation wall
Thermoplastic Composite Lumber
- Wood-like product made from wood fiber and polyethylen or PVC
- Alternative to preservative-treated lumber
- Used for outside decks and railings
Precast concrete slabs
- Solid slabs - Up to 30ft
- T slabs - Up to 120 ft
Gable roof
2 inclined surfaces that meet at their high side to create a ridge
Hip roof
Slopes in 4 directions
Gambrel roof
Slopes in 2 directions, but there will be a break in the slope on each side
Space created can be used as an attic or living space
Mansard roof
Has the break in the slope of the roof on all 4 sides
Forms a projection beyond the building wall that creates a concealed space though which fire can communicate
Butterfly roof
Slopes in 2 directions
Basically 2 shed roofs that meet at their low eaves
Monitor roof
Provides light and ventilation
Commonly used on old factory buildings
Vertical sides, which are normally openable windows are know as clerestories
Sawtooth roofs
Once commonly used on industrial buildings for light and ventilation
Ideally, the glass vertical sections should face north cause the north light is more constant during the day and the glare of the sun can be avoided
High rise construction
Model building codes
2 or 3 hour fire resistance for structural frame
2 hour fire resistance for floor construction
Piecemeal demolition
- Hand tools and machines
- Likely to involve rescue
Controlled collapse
- Demolition ball
- Hydraulic pusher arms
- Wire rope pulling
- Explosives
Temporary fire protection
- Standpipes be extended before the construction reaches 40 ft above the lowest level of the fire department access
- Top hose outlets should be within 1 story of the uppermost level having a secure floor
Source of building failure under fire conditions
- Structural integrity
- Building systems
- Design deficiencies
Interior finish affects fire behavior in the following 4 ways
- Contribute to the fire extension by flame spread over the surface of walls and ceilings
- Affects rate of fire growth
- Add to the intensity of a fire because it contributes fuel
- Can produce smoke and toxic gases that contribut to the life hazard
NFPA 220 Standard on Types of Building Construction
3 Digit Code
- 1st digit = Exterior bearing walls
- 2nd digit = Structural frames or columns and girders that support loads of more than one floor
- 3rd digit = Floor construction
Concentrated load
- Load applied at one point or over a small area
- Produce highly localized forces and nonuniform loads in the supporting structural members
Live load
- Load that is not fixed or permanent
- Can include wind and seismic loads
- Usually applied to occupants, contents and the weight of snow or rain on the roof
Dead load
- Weight of any permanent part of a building
- Roofs, floor slabs or decks, interior walls, stair systems, exterior walls and columns
- Permanent equipment ie heating plants, elevator hoists, pumps, and water supply tanks in location that is actively known
Static load
- Loads that are steady, motionless, constant or applied gradually
Dynamic load
- Loads that involve motion
- Forces arriving from wind, moving vehicles, earthquakes, vibration, falling objects
Piles
- Used to support loads
- Driven into the ground
- Develop thier load-carrying ability either through friction with the surrounding soil or by being driven into contact with rock or a load bearing soil layer
Pier
- Constructed by drilling or digging a shaft, then filling with concrete
- Belled pier - peir designed with a footing
- Caisson - protective sleeve used to keep water out of the excavation for the pier
Concrete fire resistance factors
- Density
- Thickness
- Quality
- Load supported by the concrete
- Depth of concrete cover over reinforcing bars
Elevators
- 1 or 2 hour rating for enclosure
- 3 or fewer elevators = 1 hoistway
- 4 or more elevators = must be a min of 2 hoistways
- When more than 1 hoistway is provided, up to 4 elevators may be in 1 hoistway
- Single elevator hoistways that ony serve upper levels have access doors for rescue every 3 floors
Type I construction
fire ratings
- Bearing walls, columns, and beams = 2-4 hrs
- Floor construction = 2-3
- Roof deck = 1-2… Omitted when 20ft above floor
- Interior partitions enclosing stairwells and corridors = usually 1-2
Flat Roof coverings
- Vapor barrier - Diffusion
- Thermal Insulation - heat loss; poured or rigid
- Membrane -
- Built up - overlapping
- Single ply - 10-20 ft; 200 ft long
- Fluid - curved roof surfaces
- Drainage layer - free movement to drains
- Wear course - Mechanical abrasion
Interior finishes
- Plaster, gypsum, wallboard, wood paneling, cieling tiles, plastic, fiberboard
- May or may not be structural materials
