Deck 20: Cold-Formed Steel Construction

Question 1

CFS framing for interior gypsum board partitions is designed for a minimum gravity load of

A)5 psf.
B)25 psf.
C)35 psf.
D)15 psf.
E)none of the above.

Answer 1

E

Question 2

In the identification mark on a CFS member "362S125- 30 (33)G40", the number 30 implies that

A)the thickness of steel sheet used for the member is 0.030 in.
B)it is a 30- in.- long member.
C)it is a 30- ft- long member.
D)the thickness of steel used for the member is gauge 30.
E)none of the above.

Answer 2

A

Question 3

Punchouts in CFS studs are generally spaced

A)48 in. on center.
B)24 in. on center.
C)36 in. on center.
D)12 in. on center.
E)none of the above.

Answer 3

B

Question 4

The use of CFS members in interior partitions is generally in buildings of

A)Type I construction.
B)Type II construction.
C)Type III construction.
D)Types II and III construction.
E)Types I and II construction.

Question 5

CFS framing for interior gypsum board partitions is designed for a minimum lateral load of

A)25 psf.
B)35 psf.
C)5 psf.
D)15 psf.
E)none of the above.

Question 6

In the identification mark on a CFS member "362S125- 30 (33)G40", the letter S implies that

A)it can only be used for a single- story building.
B)it is made from steel with a strength of 362 ksi.
C)it is a straight, unbent member.
D)it is an S- shaped member.
E)none of the above.

Question 7

A 20- gauge sheet steel is thicker than 22- gauge sheet steel.

Question 8

The yield strength of CFS members used for interior partitions is generally

A)20 ksi.
B)30 ksi.
C)40 ksi.
D)50 ksi.
E)none of the above.

Question 9

The yield strength of CFS members used in load- bearing applications is generally

A)20 ksi.
B)30 ksi.
C)40 ksi.
D)50 ksi.
E)none of the above.

Question 10

The gravity load supported by CFS members, used in the framing of the backup wall for exterior cladding, is small.

Question 11

The terms G40 and Cp40 refer to the same property of CFS members.

Question 12

The amount of corrosion protection required in CFS members is generally

A)Cp30.
B)Cp50.
C)Cp60.
D)Cp40.
E)varies with the application.

Question 13

The use of CFS, as an alternative to lumber, in load- bearing residential applications, has found favor in some warm, humid areas of United States because CFS is

A)more durable against termite and fungal attack.
B)lower in labor and installation cost.
C)heavier, and hence stronger.
D)noncombustible.
E)all of the above.

Question 14

The EQ studs

A)are more fire resistive.
B)provide greater sound insulation.
C)use less steel.
D)all of the above.
E)A and B.

Question 15

Both a Z- shape CFS section and a hat section are referred to as furring CFS sections.

Question 16

Cold- formed steel (CFS)is used in load- bearing walls, non- load- bearing walls, floors, and roofs.

Question 17

CFS members are generally used as framing members in exterior wall cladding in buildings of

A)Types III, IV, and V construction.
B)Types I, II, III, IV, and V construction.
C)Types I, II, and III construction.
D)Types II, III, and IV construction.
E)none of the above.

Question 18

The strength of sheet steel used for making EQ studs is

A)33 ksi.
B)50 ksi.
C)40 ksi.
D)greater than 50 ksi.
E)less than 33 ksi.

Question 19

CFS studs are C- shaped.

Question 20

The use of bridging channels requires

A)punched tracks.
B)unpunched studs.
C)punched studs.
D)unpunched tracks.
E)none of the above.

Question 21

What is the tensile strength of steel sheet used in making cold- formed steel (CFS)sections?

Question 22

Explain the difference between structural steel and cold- formed steel.

Question 23

Two types of buildings with load- bearing CFS walls have been identified in this text: (a)CFS buildings as Type V(B)construction and (b)CFS buildings as Type II(A)construction. The distinction between the two is primarily based on the

A)corrosion protection of CFS members.
B)type of materials used in floor and roof assemblies.
C)size of CFS studs.
D)extent of prefabrication used in construction.
E)none of the above.

Question 24

In designing CFS interior gypsum board partitions, we can assume either a composite structural behavior or a noncomposite structural behavior. Of the two, noncomposite behavior is more conservative because it ignores the structural contribution of the

A)gypsum board.
B)studs.
C)top track.
D)bottom track.
E)all of the above.

Question 25

CFS members are made from sheet steel that is provided with corrosion protection before it is formed into shape.

Question 26

In- line framing in a CFS structure means that

A)the floor joists from two opposite directions of an underlying supporting wall must be in line, not staggered.
B)the studs must be continuous across an intermediate floor.
C)the floor joists must align with the studs in the underlying supporting wall.
D)the floor- to- floor height in a two- or three- story structure must be the same.

Question 27

CFS members are made by roll forming of

A)flat sheets.
B)coils of sheet steel.
C)either of the above two types of sheets depending on the type of roll- forming machine.

Question 28

The corner of a load- bearing CFS wall requires a minimum of

A)three studs.
B)four studs.
C)two studs.
D)five studs.

Question 29

When bridging channels are required in an interior gypsum board partition, they must be spaced a maximum of

A)60 in. on center.
B)48 in. on center.
C)12 in. on center.
D)24 in. on center.
E)36 in. on center.

Question 30

The top track in a load- bearing CFS wall must be doubled in the same way as the top plate in a WLF wall.

Question 31

If the gypsum board in a CFS interior partition extends the full height of the partition (i.e., from top track to bottom track)on both sides, the partition is considered as

A)fully braced.
B)braced 12 in. on center if the stud spacing is 12 in.
C)braced 16 in. on center if the stud spacing is 16 in.
D)braced 24 in. on center if the stud spacing is 24 in.
E)unbraced.

Question 32

The use of two nested top tracks in the framing of an interior gypsum board partition

A)provides greater bending strength in the wall.
B)provides greater fire resistance in the wall.
C)absorbs the deflection of the overhead structure.
D)provides greater shear strength in the wall.
E)seals the partition against the passage of smoke.

Question 33

The CFS framing for an exterior non- load- bearing wall used as backup for exterior cladding can either be a bypass framing or an infill framing. The bypass framing can be used for

A)up to a one- story building.
B)up to a two- story building.
C)up to a three- story building.
D)up to a four- story building.
E)up to any number of stories.

Question 34

Two metrics are used in specifying the thickness of steel sheet used for cold- formed steel (CFS)sections. What are those metrics and what is the relationship between them? Do we use both metrics in practice or one of the two? Which metric is more important?

Question 35

If the gypsum board in a CFS interior partition extends the full height of the partition (i.e., from top track to bottom track)on both sides,

A)the assumption of a noncomposite structural behavior is valid.
B)the assumption of a composite structural behavior is valid.
C)any one of the two (composite or noncomposite behavior)is valid depending on the center- to- center spacing of studs.
D)any one of the two (composite or noncomposite behavior)is valid depending on the thickness of the gypsum board.

Question 36

The anchorage of the bottom track of a load- bearing CFS wall to the concrete footing

A)requires a 6- in.- long cold- formed furring section to strengthen the connection.
B)requires 6- in.- long additional track material to strengthen the connection.
C)requires 6- in.- long stud material to strengthen the connection.
D)requires no additional strengthening.

Question 37

WLF walls, CFS walls are assembled on site on the floor of the building and subsequently tilted up and moved into position.

Question 38

The CFS framing for an exterior non- load- bearing wall used as backup for exterior cladding can either be a bypass framing or an infill framing. In bypass framing, the studs are connected to an intermediate floor or roof through

A)a slide clip.
B)two clip angles.
C)an overhanging clip.
D)a clip angle.
E)none of the above.

Question 39

CFS framing for interior gypsum board partitions is designed

A)to a maximum permissible deflection of L/180.
B)to a maximum permissible deflection of L/120.
C)to a maximum permissible deflection of L/240.
D)to a maximum permissible deflection of L/300.
E)as needed.

Question 40

The benefit of using load- bearing CFS framing instead of load- bearing wood frame in seismic zones is the

A)greater strength of CFS members.
B)ductility of steel.
C)lighter weight of CFS framing.
D)B and C.
E)A, B, and C.

Question 41

The two most important cross- sectional shapes in cold- formed steel construction are C- shape section and U- shape section. In which members of the walls, floors, and roofs are C- shape and U- shape sections used?

Question 42

What is the minimum corrosion protection and yield strength of steel sheet required for nonstructural cold- formed steel sections?

Question 43

What are EQ studs?

Question 44

The Steel Stud Manufacturers' Association (SSMA)uses four- part information to designate a cold- formed steel section. Which are those four parts?

Question 45

Explain the difference between G60 and CP60.

Question 46

What is difference between a load- bearing member and a non- load- bearing member?

Question 47

What is a bridging channel and what is its role in cold- formed steel (CFS)construction?

Question 48

Explain the four parts of the designation of a cold- formed steel section: 1000S250- 68.

Question 49

Each cold- formed steel section is stamped with an identification mark, which gives its designation and three additional information items. Which are those additional items?

Question 50

List the building components in which cold- formed steel is used.

Question 51

The term "STUF" is an acronym that includes various cross sections used in cold- formed steel construction. Explain what STUF stands for.

Question 52

Explain all the four parts of the designation of a cold- formed steel section: 400T150- 33.

Question 53

Explain why cold- formed steel must be galvanized.

Question 54

Which of the following cold- formed steel (CFS)sections is punched with holes-studs, tracks, bridging channels, and furring sections? What is the spacing of punched holes and the reason for it?

Question 55

Cold- formed steel (CFS)studs and tracks (S+T sections)are classified as structural and nonstructural S+T sections What is the reason for separating them in two classes?

Question 56

In which situations must structural steel members be protected using G90 coating?

Question 57

What does the acronym SSMA stand for?

Question 58

Name the three furring sections used in cold- formed steel (CFS)construction.

Question 59

Name the two most important cross- sectional shapes used in cold- formed steel construction.

Question 60

Explain what G60 means.

Question 61

What is the minimum lateral load for which an interior partition wall is designed?

Question 62

Why must the yield strength of EQ studs be higher than 33 ksi-the strength commonly used for regular studs?

Question 63

Which of the following two cold- formed steel (CFS)stud walls has a higher R- value? Both walls consist of
3- 1/2- in.- deep studs and 3- 1/2- in.- thick fiberglass insulation. In wall 1, the studs are spaced 24 in. on center and in wall 2, they are spaced 12 in. on center.

Question 64

Explain what each term in the following identification mark of a CFS member means: 362S162- 43 (50)CP60.

Question 65

a. What is the minimum lateral load for which an interior drywall partition is designed?
b. What is the maximum permissible deflection (in inches)of an interior drywall partition which is 12 ft high?
c. What is meant by a fully braced drywall partition? Explain using sketches.

Question 66

Using sketches and notes, explain what bridging channels are, where they are required, and their maximum center- to- center spacing.

Question 67

Explain what EQ studs and tracks are, and describe how they differ from the standard studs and tracks.

Question 68

In which situations is load- bearing cold- formed steel (CFS)construction preferred for single- family residences?

Question 69

In which situations are bridging channels required in a non- load- bearing cold- formed steel wall, such as a partition wall?

Question 70

Sketch a typical head- of- wall detail for a non- fire- rated interior drywall partition under a reinforced concrete floor slab.

Question 71

What is the difference between a CFS member that is hot- dip galvanized and a member that is galv- annealed?

Question 72

Non- load- bearing CFS walls in a reinforced concrete or steel frame structures are of two types: interior walls and exterior walls. Interior walls are faced with gypsum board on both sides. Are the exterior walls faced with the same material?

Question 73

Why is the composite action of a cold- formed steel (CFS)backed interior gypsum board partition wall generally not achievable?

Question 74

What is deflection track in a cold- formed steel (CFS)stud wall?

Question 75

What is the maximum permissible deflection for a interior gypsum board partition if the height of the partition is 10 ft?

Question 76

Using sketches and notes, explain the difference between composite and noncomposite structural behavior with respect to CFS framing for drywall partitions.

Question 77

Is the R- value of a wood stud wall with 3- 1/2- in- deep studs and 3- 1/2- in. fiberglass insulation the same as a cold- formed steel (CFS)wall with 3- 1/2- in.- deep studs with the same insulation? Explain your answer.

Question 78

Sketch in cross section: (a)CFS stud section, (b)CFS track section, (c)CFS hat section, and (d)CFS Z section.

Question 79

Sketch a typical head- of- wall detail for a non- fire- rated interior drywall partition under a steel floor deck. The partition is parallel to deck flutes.

Question 80

What is the difference between composite and noncomposite design of cold- formed steel backed interior gypsum board partitions? Which design is more conservative?