Building Exteriors

Question 1

Kansas City Hyatt Disaster: How long was the Hyatt open before the disaster? and give some interesting points about this time

Answer 1

Began in 1978 and opened in 1980 [2 years super-fast turn around]
Opened for 12 months

Question 2

Kansas City Hyatt Disaster: GIve some opportunities to prevent the walkway failure.

Answer 2

• Check with the original design and maintain consistency
• If designs do change ensure the load of the new design works
• When accidents happen (glass panel) actually check the materials.

Question 3

Kansas City Hyatt Disaster: What was the cause of the structural failure of the walkway?

Answer 3

It failed at the connection point since the actual anticipated load it could handle was much lower in reality.

The Welled box beam being “toe to toe” is structurally weaker than an “I” steel beam.

Also, the hanging bars were split into two since the steel manufacturer could not produce it to that length.

Question 4

Who was ultimately held responsible for the disaster and why?

Answer 4

Jack Gillum and his company GCE because his team pushed the responsibility back and forth thus not checking the connections for the walkway

Question 5

Loads can be either Dead/Static or Live/dynamic Loads. What is the difference?

Answer 5

Dead loads are permanent while live loads are changing.

Dead loads: Constant/but changes (elevator)
Live Loads: Bridge with walking people

Question 6

What are the two types of resonant forces?

Answer 6

Rhythmic: Straight forces: either up or down
Tangential: Non-linear forces: both up and down

Question 7

How do downward loads create stress?

Answer 7

They cause TENSILE stress causing the force to come out the sides and push out from the center of the load.

Question 8

How do upward loads create stress?

Answer 8

Upward loads cause COMPRESSIVE STRESS thus making the force come in.

Question 9

How does tangential load create stress?

Answer 9

Tangential load causes SHEAR STRESS coming from both upward and downward directions.

Question 10

What are some things to look for in maintenance?

Answer 10

-Cracks in the wall
-Water penetration
-Are both tight and welds in tact?
-Areas of change during last inspection

Question 11

What to look for during window & door maintenance?

Answer 11

-Loose-fitting frames
-Cracked glass/glazing
-Deteriorated sealants
-Corrosion (metal frames)
-For operable windows, pins to restrict opening
-For doors, proper door-to-frmae alignment

Question 12

What are the three goals for a building’s structural frame?

Answer 12

1. Remain standing by resisting/supporting varying loads
2. Provide a way to move the load from the point of impact to the most steady part object (the ground beneath the building aka the foundation)
3. Provide redundancies so if a structural element was damaged or removed, a fatal collapse would not be imminent

Question 13

Is steel very resistant or nonresistant to compressive tensile and/or shear stresses?

Answer 13

Stell is very resistant to both tensile and shear stresses

Question 14

Who prepares the As-built and shop drawings?

Answer 14

Contractors:

As-builts: document what was actually built
Shop drawings

Question 15

Who prepares the original working drawings?

Answer 15

Architect or Engineer

Purpose: Sent to the contractor for pricing and used by them when building in the field

Question 16

Why do we use wired mess to reinforce concrete?

Answer 16

The wired mesh adds tensile strength to the concrete since regular concrete is not resistant to it.

Question 17

What is the plastic layer used to deter moisture transfer in concrete called?

Answer 17

Vapor barrier:

Looks like a tarp/shower curtain

Question 18

What are the issues that parking garages face in terms of deterioration?

Answer 18

Concrete parking recks require periodic PM work and repairs

Northern climates that use salt on roads in the winter also have to be aware it accelerates the wear on the epoxy seal and rusts the wire mesh in the concrete

Question 19

What are the four purposes of building façades?

Answer 19

1. Weather proofing
2. Thermal performance
3. Mitigating air infiltration
4. Sound attenuation

Question 20

Describe U-value and R-value

Answer 20

U-value is the rate of heat transfer: the lower this value the better
(keeps the inside and outside temps steady)

R-value the thermal resistance: the higher this value the better
(Keep in mind there is no set range all of it is comparative)

Question 21

How often should you inspect a façade?

Answer 21

At least twice per year

Question 22

What does having a double-glazed/ double panel of glass do for a building?

Answer 22

The temperature transfer is reduced since there is an air gap between the two layers thus reflecting it back and lowering the total heat transferred.

Question 23

What are the two main reasons you would have a Built-up Membrane Roofing? (BUR)

Answer 23

It is very durable, has high insulation factor but it does cost more

Question 24

Why would you choose single-ply membrane roofing?

Answer 24

[Less popular than BUR]
-Flexible
-Easy to install/repair
-Long life
-Cost-effective

Question 25

What is flashing in terms of roofing

Answer 25

Flashing is the transition between the membrane and other objects on the roof

Question 26

What is a parapet wall and why does a cap do for it?

Answer 26

A parapet wall is the extension of the wall on a building

The cap prevents damage and pushes water away from it

Question 27

What is the difference between an equipment curb and an equipment stand?

Answer 27

The equipment stand is much smaller but both are used to not put heavy equipment directly on the roofing membrane

Question 28

How does an infrared roof scan help?

Answer 28

It pinpoints moisture penetration under the roof in order to repair it

Question 29

What is the heat island effect?

Answer 29

The heat island effect is when the downtown area had a higher avrg temperature because of the absorption of heat.