7- Building Construction- Wood Construction Flashcards
Dimensional lumber is available in lengths from _ to _ feet, in _ foot increments.
8 to 24 feet ; 2 foot increments
The standard tensile strength of wood is considered about ___ psi.
700
After the tree is cut, moisture begins to leave the wood. The wood begins to ____ in size and _____ in strength.
Decrease ; Increase
The moisture content of lumber can be controlled at any level; most structural lumber has __% or less.
19
Moisture is expressed in terms of ____ _____.
Specific Gravity
A factor that affects wood strength is load direction: wood is stronger parallel to the ____ than against it.
Grain
_____ ____ components are produced from a combination of wood particles and a bonding agent.
Advantages- strength and cost efficiency
Disadvantages- quick and unpredictable failure in fire conditions when unprotected
Engineered Wood
_____ ____ products are made of flat strips of wood joined with glue. Beams constructed in this way are known as ___-______ beams.
Laminated Wood ; Glue-Laminated Beams
The ____ joint is easy to produce but cannot be used where tensile stresses will be transmitted along the length of the beam.
____ joints and ____ joints can be used to transmit tensile stresses.
Butt Joint
Scarf and Finger Joints
The thickness of finished beams ranges from __ inch to _ inches.
Finished beams may have depths ranging from _ to __ inches and lengths up to ___ feet.
Thickness ranges from 3/4” - 2”
Depths ranging from 3 - 75”
Lengths up to 100 feet
_____ Beams are used frequently in heavy timber construction where greater length components are required.
Glulam
One group of products, known as “structural composite lumber” (SCL), use the outer fibers of a log as well as the inner portions traditionally used. What are the three products?
-Laminated Veneer Lumber (LVL); used in I-joists and beam sections that are 1 3/4 to 3 1/2” thick
-Parallel Strand Lumber (PSL); strongest of the SCL products, can be used for heavily loaded columns and long spans, standard sizes ranging from 2-8’ in length
-Laminated Strand Lumber (LSL); used for short-span beams and columns, made with long strands of wood up to 12” in length
______ composite lumber is a wood-like product made from wood fiber and polyethylene or polyvinyl chloride (PVC), developed as an alternative to preservative-treated lumber. Not intended to be used in the structural framing of a building.
Thermoplastic
______ composite lumber is primarily used in the construction of outdoor decks and railings.
Advantages- resistance to weathering
Disadvantages- look like wood but melt like plastic under fire conditions
Thermoplastic
_____ panels are made up of several thin layers (veneers) rotary-sliced from rotating logs and glued together.
Plywood
Plywood is produced in standard sheets measuring ___ x ___ .
4 feet X 8 feet
_____ _____ _____ (___) uses long, strand-like wood particles compressed and glued into 3-5 layers. It is widely used for sheathing and subflooring in wood-frame buildings.
Oriented Strand Board (OSB)
_____ is not generally used for structural applications, although it may be used in lateral-force-resisting diaphragms. Manufactured in large sheets and used for flooring in manufactured and mobile homes. Made from wood particles bonded with synthetic resins under heat and pressure.
Particleboard
Particleboard can be manufactured in sizes up to __ x __ feet.
8 by 40 feet
One type of composite panel, the ____ ____ ____ (___), consists of outer wood panels (usually OSB) with a plastic foam core between the panels. The plastic foam is usually expanded polystyrene, but newer developments use foams such as expanded polyurethane to increase fire resistance.
Structural Insulated Panel (SIP)
In regards to firestopping in attic spaces, the usual requirement is for the attic space to be subdivided into areas of _____ square feet.
3,000
_____ is a layer of material installed outside of the studs to provide structural stability, insulation, and an underlayer for the siding. The most common materials used are plywood, OSB, particleboard, or exterior gypsum.
Sheathing
A layer of building wrap between the sheathing and the siding acts as a ____ ____.
Vapor Barrier
____ _____ __ _____ _____ (EIFS) are used to increase the insulative properties of a building. Because foam insulation is combustible and flame spreads rapidly over its surface, building codes impose stringent regulations on its use.
Exterior Insulation and Finishing Systems (EIFS)
Insulation can take the form of loose-fill material including:
-Granulated rock wool
-Mineral wool and glass wool
-Cellulose fiber and shredded wood
______ provides the exterior cladding of a wood-frame building. It can provide weather protection and can contribute to the appearance of a building.
Siding
A wood frame building may be provided with an exterior brick or stone _____ to provide the architectural styling of those materials with the lower cost of wood construction.
Veneer
Veneers must be tied to the wood frame wall at intervals of __ inches.
16
A typical means of adding or increasing fire resistance is through the use of 5/8” ____ ____ attached to the studs and ceiling joists.
Gypsum Board
During overhaul, firefighters can usually breach ____ _____ easily. Opening the wall aids firefighters in locating fire travel in light wood-frame construction.
Gypsum Board
Pyrolysis is the thermal decomposition of wood and begins at a temperature somewhere below approximately ___ F.
392* F
The ___ __ _____ of a fuel is the total amount of thermal energy that can be released if the fuel is completely burned. It is measured in British Thermal Units (BTUs) per pound.
Heat of Combustion
___-__-____ ___: Relationship between the available surface area of the fuel and the mass of the fuel; used to predict the rate of fire consumption of combustible material. Its impact on wood has great significance in fire fighting.
Surface-To-Mass Ratio
The two main methods of fire-retardant treatment are ____ _____ and _____ ______.
-Surface coating (used primarily to reduce the flame spread rating of wood)
-Pressure impregnation (affects the whole component and is permanent when used under proper conditions)
The wood framing systems most frequently encountered can be broadly classified into two basic types:
Light-Wood Framing and Heavy Timber Framing
Light wood framing uses nominal lumber that is _ inch at its smallest dimension.
2
In ____ ____ construction, the exterior wall studs are continuous from the foundation to the roof. Joists that support the second floor rest on ledger boards recessed into the vertical studs.
Balloon Frame
In balloon frame construction, the interior finish will act to slow the spread of fire into the stud spaces; however, a fire may penetrate the interior finish through penetrations for:
Electrical fixtures, Plumbing, or Heating
Platform framing is more prone to _____ than balloon framing because platform framing makes use of more horizontal members in its frame than a balloon frame.
Shrinkage
The shrinkage in platform framing can product greater _____ movement at different points. This movement can cause undesirable effects such as cracking of plaster and misalignment of door and window openings.
Vertical
Type IV construction (heavy timber) is characterized by heavy wooden structural interior supports with a masonry exterior. It is more similar to Type __ than Type __ construction.
More similar to Type III (exterior protected) than Type V (wood frame).
Identifiable features of heavy timber framing include:
-Internal support COLUMNS are not less than x inches and the BEAMS (except roof beams) are not less than x inches.
COLUMNS not less than 8x8”
BEAMS not less than 6x10”
The two primary differences between Type III (exterior protected) masonry construction and Type IV (heavy timber) construction are:
-Type IV has thicker dimension of wood structural members
-Type IV doesn’t allow combustible concealed spaces
Wood I-beams are commonly used in modern ____ and ____ construction.
Roof ; Floor
Light wood frame trusses use a series of _ inch nominal members that align in the same plane.
2
Heavy timber trusses use members up to _ or _ inches. In current practice, they are used mainly for their appearance.
8 or 10 inches
Wood is uniquely vulnerable to deterioration from several causes including:
Insects, decay, and shrinkage
