15 Wood-Frame Building Collapse

Question 1

There are three ways a wood-frame building can collapse during a fire:

Answer 1

1. one wall may fall straight outward at a 90-degree angle
2. the entire building may lean over and collapse on its side
3. One or all four wood enclosing walls may crack apart and fall in an inward/outward collapse

Question 2

A three-story braced frame structure frequently falls in an ___________________.

Answer 2

inward/outward collapse

Question 3

Of the three types of collapse, which is the most dangerous?

Answer 3

Inward/Outward
Because it is sudden, gives no visible warning signs prior to failure, and unlike most, it may involve two, three, or four walls simultaneously.

Question 4

Of the three major types of wood-frame construction, ________________________ buildings present the greatest FFing danger

Answer 4

braced-frame wood-constructed

Question 5

The four most widely used methods of wood-frame construction over the past 200 years are:

Answer 5

1. Braced-frame
2. Balloon frame
3. Platform frame
4. Lightweight wood frame construction

Question 6

Which of the methods is the most widely used method of wood-frame construction?

Answer 6

Platform frame

Question 7

While lightweight wood construction will still have a global failure, it suffers:

Answer 7

Early floor and roof collapse

Question 8

How deep do the metal gusset plates penetrate into the wood?

Answer 8

3/8 to 1/2 inch

Question 9

The Underwriters Testing Laboratory documents lightweight wood truss and sheet metal fasteners failed in less than ________________ of fire exposure.

Answer 9

10 minutes

Question 10

Three factors contribute to the inward/outward collapse of a braced-framed wooden building:

Answer 10

1. Fire destruction of bearing walls
2. Failure at the mortise-and-tenon connection
3. Exterior wall overload

Question 11

Private homes, built on large plots of land, are designed to have the larger area of the building face t he street, so the front and rear walls are ________________________. Condominiums and row town houses have this same design.

Answer 11

Load-bearing walls (two sides are non-load-bearing.

Question 12

In peaked roof buildings, the bearing walls support roof rafters and are __________ to the ridgepole.

Answer 12

parallel

Question 13

In flat-roofed wood buildings, the bearing walls are usually the walls with the ___________________.

Answer 13

greatest dimensions. The non-load-bearing walls have the shortest dimensions

Question 14

The wood mortise-and-tenon connection is susceptible to collapse by ______________.

Answer 14

Rotting