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Legacy construction sawn beam has been replaced by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