Brannigans Building Construction CH.8 Wood Frame Construction (PT.2) Flashcards
Legacy construction sawn beam has been replaced by
I beam (composite wood joist)
Composite wood joist
I beam
New I beams use what instead of plywood webs
OSB for web; 2x4 for upper lower flanges
Present-day high beams are glued together using what and are manufactures in lengths up to 60 ft
using phenol and Resorcinol formaldehydes
The gradually sagging of Sawn beams due to the loss of exterior wood often gives warning us
Impending collapse
Any Fire gets a grip on both sides of the I beams at the same time guarantees
Early failure
often cut off ends of I beams are used as
Fire stopping
Recent test of wooden I beams have shown failure in just over how many minutes in a simulated basement fire at Underwriters Laboratories (UL)
6 minutes
T or F: even if their isn’t direct flame impingement on the beams, convection heat is sufficient to destroy the joist webs and compromise their points of support
true
Can be considered the most dangerous of all structure members to Firefighters today; they feel incredibly fast often soon after the arrival of firefighters on scene
wooden I joist and lightweight wood trusses
The US Forest Products laboratory developed
Truss framed Construction
Type of construction in which truss roof and perhaps truss floors are substituted for sawn beams; held together by nails
Truss framed Construction
In a truss frame construction the studs are an integral part of both what
Roof and floor trusses; tied into unitized frame
In truss frame Construction unsupported spans and Trussed structures are subject to Total collapse and the loss of a stud due to fire could precipitate
Collapse of the integral roof or floor Truss
Plane structural components; to firefighters disposable buildings
Truss frame structures
In truss frame Construction what must provide adequate support to hold every trust in its design position and to resist lateral forces
Permanent bracing
One of the major problems of combustible construction is
Fire spread through hidden voids
These limit spread of Fire by preventing movement of flame hot gases and smoke to other areas of the buildings
Firestopping and draftstopping
Typically limit vertical movement through relatively small concealed passages such as under stairs and inside walls
Fire stops
Consist of at least 2 in. nominal lumber, 2 thickness of 1in. nominal lumber with broken up lap joints, or 23/32 in. plywood or other approved materials
Fire stopping material
Limit horizontal movement through large concealed passages such as open web floor trusses for attics
Draft stops
May consist of at least one and a half in. gypsum board, 3/8in. Plywood, sheet metal, or other approved materials, usually applied parallel to the main framing members
Draftstopping materials
To have a chance at stopping a fire in an attic what must be properly installed and maintained
Draft stopping
Proper what allows you to get ahead of the fire by opening up ceilings adjacent to the involved area and surrounding the fire
draftstopping
Two types of fire stopping
Inherent and legal fire stopping
Type of fire stopping that comes as a result of the normal building construction
Inherent fire stopping
In the case of wood platform frame Construction, the sole plate at the base of each floors exterior wall and the top plates at the top of each floors wall provides
Inherent fire stopping
Type of fire stopping that is installed only to meet the requirements of a code; May provide barrier to the spread of fire in the interior void of the building; often ineffective
Legal fire stopping
Lack of what in one stud Channel is sufficient to transmit fire all the way from the seller to the Attic
Lack of fire stopping
The space formed by the sides of two studs and the exterior and interior walls
Stud Channel
In older houses, both the exterior sheathing and the lathing on the interior walls are made of wood so all four sides of the chimney like stud channels are
Combustible
If the temperature rises and the volume Remains the Same, the pressure Rises; leaving and inconsequential opening and the fire stopping well in effect create a
Nozzle
Wood fire stopping is often made from the cutoff ends of
joists
Recent fire stopping or draftstopping practices consists of a sheet of gypsum board buttered into place or a piece of thin plywood or flack board poorly fitted these techniques are
Ineffective
This is often removed or penetrated once installed for the installation of such items as heat ducts, electrical cables, sprinkler systems, and central vacuum cleaner systems
Fire stopping
Installed for the purpose to stop a gas under pressure and limit the spread of Fire
Draft stopping or fire stopping
In multiple-unit dwellings recommended location for firestopping it’s along
Tenant separation so that the entire floor ceiling area above and/or below unit on fire is a collapse area
T or F: even if draftstopping installed around the perimeter of effective space is successful this will not prevent the collapse of the affected area
true; atleast 500 ft^2 in single family residential and 1000ft^2 in other buildings
Attempts to protect wood by encasing it in cement like products were found to be dangerous because
Wood, not being exposed to the air, tends to decay
T or F: wood cannot be made fireproof or non-combustible; it can be made fire retardant by impregnation with mineral salts which slows its rate of burning
True
Accomplished by placing wood in a vacuum chamber drawing out moisture from its cells and forcing mineral salts into the wood
Impregnation of wood
Some codes except the use of impregnated wood in
non-combustibles places
Impregnated wood with mineral salts do not penetrate deeply and the removal of surface wood may
Destroy fire retardant treatment
Pressure treatment can significantly reduce Woods
Flame spread
Often is called fire retardant treated (FRT) wood
Treated lumber
Plywood treated with certain chemicals decays from Heat and is subject to
Failure if walked on
In an attempt to provide a barrier to the spread of fire over an unparapeted firewall, some jurisdictions require
Sheet of gypsum board to be attached to the underside of the roof on each side of the firewall
Fire hazard or flame spread of wood can also be reduced by the application of
Intumescent Coatings that swell up when heated
One of the major problems with surface coating is a tendency for it to be
Spread thinner than its recommended thickness; needs to be reapplied as certain intervals to retain its proper function
Woods that resist insects and moisture (pressure-treated) have been used for basement walls; are combustible and might cause a collapse fumes from such pressure treated wood are toxic
Plywood & Lumber treated
Sliced wood into thin layers, layers placed at right angles to one another and entire mask glued together create what; equally strong in all directions
Plywood
A basic problem of plywood exposed to fire is that it eliminates which increases what
Surface area and rate of heat release
T or F: plywood can be impregnated to render it fire retardant
True
Type of construction in which plywood provides some of the structural strength of the building particularly and providing resistance to Shear stresses
stressed skin or diaphragm Construction
Various metal connections are used to transfer loads so that spliced Timber acts like a
Single Timber
Plank like sections of nominal 2-inch (or thinner) boards are glued together Under Pressure to produce large arches, Beams, girders, and columns; sometimes bolts are used to supplement the glue
Glulam, laminated Timbers
Burn like solid heavy Timbers and to not delaminate like plywood
Laminated Timbers
T or F: laminated wood beams do not delaminate
True
T or F: Plywood that is used in wooden I beams can delaminate
True
Combined in one member both column and girder; provide a straight walled structure with a flat roof and a clear floor area
Two hinge arches of laminated wood
Laminated Timbers and other finally finished wood are shipped in a protective paper wrapper; paper is hemp reinforced and coated with bituminous moisture repellent which can do what
Ignite readily, High flame spread, can contribute to severe lost in building under construction
Often fabricated without waste by gluing three boards together with Center board protruding on one side and indented on the other
Tongue and groove roof planks
During a fire these plants May separate like plywood causing the boards to fall from overhead
Tongue and groove planks
Wood chips are glued together to make flat sheets; sometimes used for floors of mobile homes; can be water soluble
chipboards (aka particleboard)
Composite of a steel plate sandwich between two solid sawn wood joist or in some cases plywood
flitch plate girders
Covering that is applied to the studs or framing of a structure
Sheathing
Moisture and Vermin proofed; used in residential construction because it can be installed quickly and has relatively High insulation value
Low-density black fiberboard
Low density fiberboard material carries a combustible warning; the common method of ignition of this material is
Plumber’s torch
Plywood can be used as sheathing or used add quarters to provide
Shear strength
Type of sheathing found in some locations where combustible sheathing is not permitted
Gypsum
Combined brick veneer surfacing and gypsum interior surface is used to provide
Rated fire-resistive exterior walls
Now widely used for sheathing; may or may not be flame inhibited and if exposed to fire it may degrade and give off noxious fumes
Foamed plastic
On a building it is the outer weather surface installed over the sheathing
Siding
On the outside of the building what can readily extend fired vertically and is easily ignited buy an exterior fire such as trash or burning foliage
Combustible siding
Often called clapboard, laid on horizontally and of wood
Novelty siding (wood siding)
Consist of boards laid on vertically butt to butt wood strips nailed over joints
Board and batten siding
type of siding Delivered in 4 ft wide sheets, side matched, give appearance of 4 in wide strips about 1/2 in apart
Plywood siding (aka T1-11 plywood)
A siding they do not present the extreme conflagration Hazard of wood shingled roofs
Shingles and Shakes
(long, thicker shingles are called shakes)
siding that is non combustible but the presence of wood trim and often old wood siding renders building with this type of siding just as vulnerable to a grass or trash fire as a wooden building
Asbestos cement shingle
Siding that can explode when heated and flying particles can cause eye injuries and possible inhalation hazards
Asbestos cement shingles
Known as gasoline siding; usually made to look like brick or stone and burns readily and produces dense black smoke
Asphalt felt siding
T or F: asphalt siding has some fire resistance value
false; it does not
Made to look like wood siding; thermoplastic that will deform (droop) burn, and drip under attack from a fire; often used to cover up old wood siding
Vinyl siding
Type of metal siding that can present severe electrical hazards both from stray electrical currents and from lightning; used on industrial buildings of wood or steel framing
Corrugated metal siding
Thin concrete surface that can be used on any structures such as brick block hollow tile or wood; can improve exposure protection over that of comparable wood surface buildings
Stucco
In the case of wood stucco is laid on metal lath, lath makes it difficult to
Make openings in the wall
Type of siding that is popular for wood frame residences, Garden Apartments, and smaller commercial buildings
Brick veneer siding
T or F: brick veneer siding it’s not structural so it carries no load except itself
True
Brick veneer walls are laid up from
Foundation and one wythe
1 thickness of brick in a wall
wythe
in a veneered wall, galvanized steel anchors are nailed to
Studs
in a veneered wall, the anchors are bent at right angle and embedded in the mortar between two brick courses (or layers); if there is a fire in the wall the nails made detach from the studs do to
Pyrolytic decomposition
T or F: natural or artificial stone and cast concrete are also used as veneer
True
Stones used as veneers are mortared to
wire lath base
Split pieces of wood that are used for roofing or siding; some of the greatest fire disasters have been due to the spread of Fire by these
Wood shingles or shakes
Wood shingled roofs are permitted wherever what type of buildings are permitted
Frame buildings
Standard methods of fire test of roof coverings
NFPA 256
Roofing materials are classified as a b or c; the least fire-resistant is rated
c
Treated shingles exposed to weather effects will lose
Effectiveness
Imitation beams often found in conjunction with plywood veneers that are readily ignitable and burn fiercly; hazards include massive fire load overhead and potential for collapse
Polyurethane imitation wood beams and fittings such as brackets
In newer construction which is stronger floors or roofs
Floors
Quickly succumbs to fire; can also lose its structural strength and fail when it becomes saturated with water
OSB or oriented flakeboard
An older construction homes what is one indicator of balloon frame structure
Tall narrow windows
In balloon frame building fire you should investigate all parts of the building immediately and be aware of potential for intensifier build up in
Void spaces
In balloon frame structure if a fire starts in the basement you need to quickly check
Attic
In balloon frame structure if fire starts on floor 1, 2, or above you need to check what
Basement; burning embers and debris scan fall from upper stories down to the foundation which can start a fire below
In a balloon frame building the problem with an interior attack is that fire moves up through
Multiple stud channels
Navy fog applicators and piercing nozzles can convert spray into steam and travel through same channel as fire in a
Balloon frame building
the safest and most effective way to attack a fire in a balloon frame structure is by
Removing exterior siding
in a balloon frame structure, the 1x6 in. wood sheathing or lath and plaster carry a lot of the weight of interior walls that is why it is best to use what for interior attacks
Piercing nozzle or fog applicator
in a wall fire the attic is considered an extension of the wall you should resist the urge to do what and why
Cut ventilation hole in roof; will complete the chimney and draw fire into attic and structural members of roof
in a wall fire, if the roof stays intact the atmosphere though charged with heat and smoke is oxygen-deficient and will not sustain a fire this allows crews to
Extinguish a fire from the exterior
These can exist above built-in cabinets in a kitchen, in the underside of stairways, in bathrooms or projecting eaves and in balloon frame construction these generally lack fire stops, can be a direct path to fire to enter the wall and joist spaces and can allow for fire to quickly spread vertically and horizontally
Soffits or void spaces
If water is flowing over a combustible surface it will not
Burn
T or F: water curtain does not protect an exposure, radiant heat can travel right through the spray you must cover the exposure with water
True
Fire burning in balloon frame walls destroys the
Structural Integrity of the building
In balloon frame building fire, watch for signs of fire spread such as
-Heavy volumes of smoke pushing out from voids in building
-intense heat buildup and structural failure (may not be apparent from close range)
Where a plank beam ceiling is already or about to become involved in fire prepare for heavy stream attack with
solid stream tips to reach surface of wood with maximum water flow
Compression load of a truss is carried on the what; typically a Lightwood members such as 2x4 or 2x6 in
Top chord
In a truss, the entire tensile load is carried on the; one brake can precipitate failure
Bottom chord
One of the purposes of installing sprinklers is to prevent
Flashover
T or F: sprinklers are fused by heat not necessarily By Flame contact
True
If first in unit is under staff and fire is gaining momentum you can consider an attack with
Blitz attack
The British thermal units (BTU) generated by a growing Fire have to be overwhelmed by
Gallons per minute (water)
As far as life Hazard is concerned if a fire is large enough to require a blitz attack the rescue profile is probably
zero
In areas where many buildings have wood shingle roofs prepare for attack with what to knock down the original fire
Blitz; call for additional unit immediately
