Chap 15 Wood Frame Building Collapse

Question 0

What is the most dangerous type of wood frame collapse for ff

Answer 0

Inward/outward collapse

Because it is sudden has no visible warning signs and may involve collapse of 2, 3 or 4 walls simultaneously

Question 1

3 ways a wood frame building can collapse at a fire ?

Answer 1

1. One wall may fall outward at 90 degree angle
2. The entire building may lean- over and collapse to one side
3. One or all 4 wood enclosing walls may crack apart and fall in an inward-outward collapse

Question 2

What are corner safe areas

Answer 2

The 4 flanking zones around a burning wood frame building

Question 3

Braced frame construction

Answer 3

Presents the greatest fire danger
Indicated by mortise and tenon
Also called post and girt

Question 4

Ballon frame construction

Answer 4

Advantages are speed in construction and absences of heavy timbers
Disadvantage is the vertical void between the wall studs which extends from foundation sill to the attic cap and allows hidden fire and in wall space to spread vertically for 2 to 3 floors
Check attic early

Question 5

Platform construction

Answer 5

From fire protection standpoint considered superior

No concealed voids that run more than one floor Builds structure one level at a time

Question 6

Light weight wood construction

Answer 6

Inferior from fire point of view
Danger is early floor and roof collapse of truss floors and roof
Strategy when fire involves truss structure such as concealed space of flat floor or roof
1. Remove occupants
2. Fight fire defensively

Question 7

Causes of inward outward collapse

Answer 7

Fire destruction of bearing walls
Failure of mortise and tenon connection
Exterior wall overload

Question 8

According to Dunn bearing walls in peaked roof pd construction will be

Answer 8

The walls parallel to the ridge pole

And support the ridge rafter

Question 9

According to Dunn the bearing walls in flat roof construction will be the

Answer 9

Walls with greatest dimensions

Question 10

Mortise and tenon joints

Answer 10

Used in braced frame construction (post and girt)

Weakest point of this type construction

Question 11

Exterior wall overload

Answer 11

Caused by fire escapes anchored to 2x4 studs anchored to wood sheathing of outside wall
Causes wood to bow and studs to curve
Changes load on studs from axial to eccentric
Fire escape must be considered structural danger

Question 12

Stucco and wire mesh on the outside of wood frame structures can add as much as

Answer 12

8 pounds of per square foot