Chapter 7 - Wood Construction Flashcards
Wood has a unique position among building materials. Because it is a plant product most of its “manufacture” actually occurs in _________.
nature
p 197
Wood is ________ to produce and renewable; however, little control can be exercised over wood as a __________.
cheap / product
p 197
As a building material wood has some disadvantages. For one thing, wood is never ______________ true. In addition, weather conditions can change its ______ and _______ and wood does not shrink or swell ___________.
dimensionally / size and shape / uniformly
p 198
Wood is stronger in a direction ___________ to the grain than against the grain. For example, the allowable compressive strength parallel to the grain varies from ______ to _______ psi for commercially available grades and species of framing lumber.
parallel / 325 to 1700
p 198
Wood has a useful __________ strength. In fact, on the basis of strength to weight, wood has a tensile strength comparable to _________. Typical defects in wood, however, greatly reduce this comparison, so the allowable tensile strength of wood is about ______ psi.
tensile / steel / 700
p 198
The strength of wood is also affected by its __________ content.
moisture
p 198
When the tree is cut, the water begins to evaporate. As the water leaves the wood, either naturally or through drying, the wood begins to ________ in size and increase in __________.
shrink / strength
p 198
It is possible to dry lumber to any moisture content, but most structural lumber has a moisture content of _____ percent or less.
19
p 198
- Lengths of wood cut and prepared for use in construction.
Lumber
p 198
Lumber is graded for both structural __________ and ____________. Lumber that has a higher grade is more _________.
strength / appearance / costly
p 198
Solid lumber includes _________, ___________ lumber, and _________.
boards, dimensional / timbers
p 199
Solid lumber:
Boards have a nominal thickness of ____ inches or less.
2
p 199
Solid lumber
Dimension lumber has a nominal thickness of ____ to ____ inches or more.
2 to 4
p 199
Solid lumber:
Timbers have a nominal thickness of ____ inches or more.
5
p 199
Solid lumber:
Dimension lumber is available in lengths from ____ to ____ feet in ____ foot increments. In addition, members for use as rafters can be supplied in lengths up to _____ feet.
8 to 18 / 2 / 24
p 199
Lumber sizes are typically given in __________ dimensions. The actual dimension of a finished piece of wood will be _________ than the nominal dimension.
nominal / smaller
p 199
Solid lumber
Thus a nominal 2x4 inch board will have finished dimensions of ____ X _____ inches.
1 1/2 X 3 1/2
p 199
____________ wood members are produced by joining flat strips of wood with glue.
Laminated
p 199
Laminated wood members
The beams produced by this method are known as ________ beams.
glulam
p 199
- Short for glue-laminated structural lumber.
Glulam
p 199
Laminated wood members
The thickness of the individual laminations varies from ____ inch to ____ inches.
3/4 / 2
p 199
Laminated wood members
The advantage to producing laminated structural members is that ________ and _________ can be produced that are not available from solid pieces cut from logs.
sizes and shapes
p 199
Laminated wood members
________ beams can be formed into curves or given varying cross sections.
Glulam
p 199
Laminated members can be produced in depths ranging from ___ to ____ inches and lengths up to _____ feet.
3 to 75 / 100
p 200
Laminated wood members
Three types of joints can be used to join laminated members end to end. These are the ______ joint, the _______ joint, and the ________ joint.
butt / scarf / finger
p 200
Laminated wood members
The ______ joint is easy to produce but cannot be used where tensile forces are to be transmitted along the length of the beam.
butt
p 200
Laminated wood members
The _______ and ________ type joints can be used to transmit tensile forces.
scarf / finger
p 200
These products allow the use of the outer fibers of a log as well as the inner portions traditionally used. The products include laminated veneer lumber (LVL), parallel strand lumber (PSL) and laminated strand lumber (LSL) ?
Structural Composite Lumber
p 201
- Surface layer of attractive material laid over a base of common material.
Veneer
p 201
Structural composite lumber
___________ __________ lumber is produced by peeling sheets of veneer from the outer portions of a log. These sheets of veneer are laminated in parallel alignment.
Laminated veneer
p 201
Structural composite lumber
__________ _________ lumber is made from the outermost veneers peeled from a log that are as uniform as those used in LVL.
Parallel strand
p 201
Parallel strand lumber
These veneers range from ____ to ____ feet in length and produce odd-shaped strands that are coated with an adhesive and ________ under pressure.
2 to 8 / cured
p 201
______ is the strongest of the three SCL products and can be used for heavily loaded columns and long spans.
PSL
p 201
Structural composite lumber
___________ ________ lumber is produced by taking long strands of wood up to 12 inches in length and bonding them with a resin in a steam pressing process.
Laminated strand
p 201
Structural composite lumber
______ is typically used for short-span beams and columns.
LSL
p 201
__________ panels are made up of several thin layers or veneers that are rotary sliced from rotating logs and glued together.
Plywood
p 201
Plywood
The thickness of individual layers varies from ____ inch to ____ inch. The nominal thickness of panels varies from ____ inch to _____ inches. Plywood is produced in standard sheets measuring ____ feet by ____ feet.
1/16 - 5/16 / 1/4 - 1 1/8 / 4 X 8
p 201
Nonveneered products include _________ _______ board, _____________, and ____________.
oriented strand board (OSB) / particleboard / waferboard
p 202
- Construction material made of many small wooden pieces (strands) bonded together to form sheets, similar to plywood.
Oriented Strand Board (OSB)
p 202
Nonveneered panels
This board uses long, strand like wood particles that are compressed and glued into three to five layers. The strands are oriented with each layer in the same direction, similar to the grain in the veneer layers in plywood ?
Oriented strand board
p 202
Nonveneered panels
This board is made from wood particles bonded with synthetic resins under heat and pressure. The individual wood particles can range in size from 1 inch to very fine ?
Particleboard
p 202
Particleboard can be manufactured in sizes up to ____ by ____ feet.
8 by 40
p 202
Because it can be manufactured in large sheets, particleboard is used for __________ in manufactured and mobile homes.
flooring
p 202
Nonveneered panels
This board is similar to particleboard but uses wafer-like pieces of wood that are larger than those used in particleboard ?
Waferboard
p 202
- Produced with parallel external face veneers bonded to a core of reconstituted fibers.
Composite Panels
p 202
_____________ panels consists of a face and back panel such as plywood or OSB bonded to a central core material.
Composite ( or sandwich panels )
p 202
Composite or sandwich panels
The core can be a variety of materials such as ________ ____________ or _________ ________.
paper honeycomb or plastic foam
p 202
Composite or sandwich panels
One type of composite panel is the __________ ________ ________. A __________ ___________ _________ consists of outer wood panels (usually OSB) with a plastic foam core between the panels.
structural insulated panel / structural insulated panel
p 202
Composite or sandwich panels
Structural insulated panels are used where energy ___________ is desired. The inner core can be up to ___ foot thick.
efficiency / 1
p 202
Span rating
Wood panel products are graded for their __________ use and their ___________ durability.
structural / exposure
p 202
Span rating
The span rating of 32/16 indicates that the panel may be used as roof sheathing on _________ 32 inches apart or as subflooring on _______ 16 inches apart.
rafters / joists
p 203
Span rating
Greater distances typically exist between the supporting members in _______ than in ________.
roofs / floors
p 203
____________ members are prefabricated from components such as dimension lumber, panels, adhesives, and metal fasteners and shipped to the construction site for election.
Manufactured
p 203
Manufacturing members away from the _____ ______ permits greater quality control and more efficient use of materials than assembling them at the construction site.
job site
p 203
Trusses
Light frame trusses are made up of ____ inch nominal members that are all in the same plane.
2
p 204
Trusses
Light frame trusses have become very popular for roof framing where the spans are ________ or ___________.
small or moderate
p 204
Light frame wood trusses pose a special problem for firefighters because the relatively slender wood members used to construct the truss will _____ _________ in a fire than the heavier members used in the past.
fail earlier
p 204
Trusses
Concern has also been expressed about the possible early failure of the ?
metal connector plates
p 204
Trusses
Heavy timber trusses are made up of members up to ____ or ____ inches.
8 to 10
p 205
Trusses
In current practice heavy timber trusses are used mainly for their ______________.
appearance
p 205
Trusses
In modern heavy timber trusses ________ gusset plates with through-_______ are frequently used at the connection points.
steel / bolts
p 205
A ______-______ truss makes use of a short circular piece of steel within and between two adjacent wood members to transfer the load between the members.
split-ring
p 205
________-_______ connectors are used in wood connections to reduce the stress at the bolts.
Split-ring
p 206
Materials with relatively _______ ignition temperatures are easier to ignite than materials with ______ ignition temperatures.
low / high
p 207
- Thermal or chemical decomposition of fuel (matter) because of heat that generally results in the lowered ignition temperature of the material. The pre ignition combustion phase of burning during which heat energy is absorbed by the fuel, which in turn gives off flammable tars, pitches and gases.
Pyrolysis
p 208
____________ is the thermal decomposition of wood and begins at a temperature somewhere below approximately ______*F.
Pyrolysis / 392
p 208
- Temperature of the surrounding environment.
Ambient temperature
p 208
The _______ of ____________ of a fuel is the total amount of thermal energy that could be released if the fuel were completely burned.
heat of combustion
p 208
The heat of combustion is measured in _________ __________ ______ per pound or ___________ per gram.
British Thermal Units (Btu) / kilojoules
p 208
Example of heat of combustion:
Using a 12 pound natural Christmas tree for an example at 8000 Btu per pound would equal _________ Btus of heat energy released if the tree is fully consumed.
96,000
p 208
A greater __________ _______ for a given mass of wood permits a more rapid combining of fuel vapors and air for combustion and, therefore, an overall greater rate of burning.
surface area
p 209
- The ratio of the surface area of the fuel to the mass of the fuel.
Surface-to-mass ratio
p 209
- Any substance, except plain water, that is applied to another material or substance and that is designed to reduce the flammability of fuels or slow their rate of combustion by chemical or physical action.
Fire retardant
p 210
The two main methods of fire retardant treatment are ___________ ______________ and ___________ ____________.
pressure impregnation and surface coating
p 210
Pressure impregnation has the advantage of producing a treatment that is ____________ when used under the proper conditions.
permanent
p 210
Most fire retardant chemicals operate by accelerating the formation of ___________ in the wood when the wood is exposed to heat.
charring
p 210
Fire retardant treatment
The __________ reduces the formation of volatile gases in the wood and retards the actual flaming combustion. The chemical reaction of the fire retardant is intended to occur at temperatures __________ than those that are developed in fires.
charring / lower
p 210
The fire retardant treatment of wood will reduce its __________.
strength
p 210
________________ ___________ lumber is a wood like product produced from wood fiber and polyethylene or polyvinyl chloride (PVC).
Thermoplastic composite
p 211
Thermoplastic composite lumber is not intended to be used in the ___________ ____________ of a building such as beams, trusses, or studs. It main application is in the construction of outside ________ and ____________.
structural framing / decks and railings
p 211
Thermoplastic composite lumber is a combustible product with a flame spread rating of _____.
80
p 212
Thermoplastic composite lumber looks much like ordinary lumber but will behave like __________ under fire conditions.
plastic
p 212
The wood framing systems most frequently encountered can be broadly classified into two basic types: __________ framing and _______-_______ framing.
timber / light-wood
p 212
Because of labor costs and limitations in the basic strength of wood, most wood frame buildings do not exceed ________ stories.
three
p 212
In heavy timber framing the columns are not less than ___ X ___ inches and the beams (except roof beams) are not less than ____ X ____ inches.
8 X 8 / 6 X 10
p 212
Because they are more _________ and have a ________ surface-area-to-mass ratio heavy timbers display greater structural endurance under fire conditions than members used in light frame construction.
massive / lower
p 213
- Notch, hole, or space cut into a piece of timber to receive the projecting part (tenon) of another piece of timber.
Mortise
p 214
- Projecting member in a piece of wood or other material for insertion into a mortise to make a joint.
Tenon
p 214
The __________ beams are used frequently in heavy timber construction where greater lengths are required.
glulam
p 214
Glulam beams behave in the same manner under fire conditions as _______ _________.
solid timbers
p 214
Information available from the US Department of Agriculture indicates that heat of a fire has essentially no effect on the _____________ that are used in contemporary glulam beams.
adhesives
p 214
_______ and _______ framing is a form of wood frame construction in which the columns (termed the posts) and the beams are of dimensions less than those used in heavy timber framing but greater than those used in light frame construction.
Post and beam
p 215
Post and beam framing
The posts are usually ___ X ____ inches or ____ X ____ inches. The posts are usually spaced ____ to ____ feet.
4 X 4 / 6 X 6 / 4 to 12
p 215
The most popular form of wood framing is known as _______ _______ frame construction.
light wood
p 216
Light wood framing makes use of ___ inch nominal lumber such as ___x___ or ___x___.
2 / 2x4s / 2x8s
p 216
Light wood framing
The walls are formed from vertical members known as “studs” that are ___x___ or ____x____ spaced ____, ____, or ____ inches on center.
2x4s / 2x6s / 12, 16, or 24
p 216
The two basic types of light wood framing are __________ framing and _________ framing.
balloon / platform
p 216
In ___________ -frame construction, the exterior wall studs are continuous from the foundation to the roof.
balloon
p 216
Shrinkage in lumber occurs to a greater degree in the _______-___________ dimensions than in its length.
cross-sectional
p 217
In ___________ framing (also sometimes known as Western framing), the exterior wall vertical studs are not continuous to the second floor.
platform
p 218
- Type of framing in which each floor is built as a separate platform and the studs are not continuous beyond each floor. Also called Western Frame Construction.
Platform frame construction
p 218
From a construction standpoint, __________-frame buildings are easier to erect than __________-frame buildings.
platform / balloon
p 218
- Solid materials such as wood blocks, used to prevent or limit the vertical and horizontal spread of fire and the products of combustion in hollow walls or floors, above false ceilings, in penetrations for plumbing or electrical installations, in penetrations of a fire rated assembly or in cocklofts and crawl spaces.
Fire stop
p 219
- Dividers hung from the ceiling in large open areas that are designed to minimize the mushrooming effect of heat and smoke.
Draft stops (also called curtain boards and draft curtains)
p 220
- (1) Covering applied to the framing of a building to which siding is applied. (2) First layer of roof covering laid directly over the rafters or other roof supports. It may be plywood, chipboard sheets, or planks that are butted together or spaced about 1 inch apart.
Sheathing (also called decking or roof decking)
p 220
A layer of ___________ _________ is provided between the sheathing and the siding to act as a vapor barrier. The ________ acts to reduce the infiltration of moisture and air.
building paper / paper
p 220
Insulation
Typically, a code will require that foam insulation be faced with a ___________ __________ such as gypsum wallboard to prevent or retard surface ignition of the foam.
thermal barrier
p 221
Noncombustible materials can be used for insulation. These include ________ wool and ______ wool in the form of batts or blankets or ________ glass.
glass / rock / fiber
p 221
A wood framed building like other buildings can be provided with an exterior facing of brick. Such construction is termed ________ _________.
brick veneer
p 223
The brick veneer adds little to structural support and must be tied to the wood frame wall at intervals of _____ inches.
16
p 223
Where a degree of fire resistance is required, the interior finish materials most commonly used are ________ ________ or _________.
gypsum board or plaster
p 223
__________-___________ gypsum board is indistinguishable from ordinary gypsum board, but will prove more difficult to penetrate with hand tools.
Impact-resistant
p 224
__________-__________ construction is intended to decrease the vulnerability of structures to exposure from wildland fires.
Ignition-resistant
p 226
Wood frame buildings, especially light wood frame buildings, have numerous concealed spaces within the _______, _______, and ________ spaces. These concealed spaces provide an avenue for the ________ of ______.
walls, attics and floor spaces / spread of fire
p 227
