Uta Construction Management, Module 7.1

Front 1

Anything below _______% pitch is considered low-slope roof.

Back 1

25%

Front 2

1. Name 2 benefits of low-slope roofs.


2. What are 2 disadvantages of low-slope roofs?

Back 2

1. Dual function, like parking, terrace or function space, house eqpt; less expensive

2. Slow drainage; prone to damage from structural movement and water vapor pressure.

Front 3

Name 5 basic components of low-slope roofs.

Back 3

1. Deck
2. Thermal insulation
3. Vapour retarder
4. Roof membrane
5. Drainage

Front 4

What is the minimum allowable slope for a roof?

How is that pitch created?

Back 4

2%

Either pitch the structure itself, or
use tapered insulation

Front 5

Name the two common types of roof deck.

Back 5

1. Corrugated steel decking, with or without concrete top
2. Concrete slab

Front 6

What causes water to puddle on a roof?


_________ _________ _________ is when water puddles and cause deflection of the roof, that allows more water to puddle and more deflection, until it collapses.

Back 6

Slope too shallow
Blocked drainage
Structural deflection
Progressive structural collapse

Front 7

What type of insulation is installed below the deck?

Pro and con of this arrangement?

Back 7

Batt (requires vented air space for condensation)

Economical, but leaves membrane and deck exposed to big variations in temperature

Front 8

3 types of arrangement of roof components - most common first.

Back 8

1. Rock ballast - membrane - rigid insulation - bitumen - rigid insulation - deck (membrane -insulation - deck)
2. Protected membrane roof (insulation - membrane - deck)
3. (Batt) insulation below deck

Front 9

__________ ________ are installed in roofs to allow water vapor to escape from the insulation layer.
It's critical to allow venting.

Back 9

Topside vents

Front 10

What two things can happen if water vapor becomes trapped below the membrane?

Back 10

1. Decay insulation
2. Cause blisters that can burst and create leaks

Front 11

What are the two advantages of membrane below insulation?

Back 11

1. Membrane is protected from extreme temperatures
2. Trapped water vapor is not an issue.

Front 12

1. What are 2 functions of ballast?

2. Name 3 common types of ballast materials.

Back 12

1. Protect from sunlight and hold everything down.

2. Crushed stone
Thin layer of concrete, pre-applied
Concrete pavers

Front 13

Name 3 types of membranes.

Back 13

1. BUR (built up roof)
2. Single-ply
3. Spray on, fluid applied

Front 14

Describe BUR membrane.

Back 14

Made of asphalt felt tiles,
in 2-4 layers
overlapping
stuck together with bitumen

Front 15

What are the 2 advantages of single ply membranes?

Back 15

Less labor to install than BUR
More elastic & less prone to tear.

Front 16

Two types of single ply membrane are:

Back 16

Thermoplastic - softened by heat; heat or solvent at seams

Thermosetting - joined by adhesive (not softened by heat)

Front 17

How is single-ply membrane attached to roof?
3 ways

Back 17

Adhesives
Ballast
Mechanical fasteners, at seam or non-penetrating

Front 18

What is the primary use for fluid applied membrane?

Disadvantage?

Back 18

Complex shapes like domes.

If a leak occurs, water becomes trapped and can't get out, causing problems.

Front 19

Name three ways to produce slope on a roof.

Back 19

1. Build the structure with slope (triangular truss)
2. Concrete screed with slope laid on level roof deck
3. Tapered insulation on level roof deck

Front 20

What is glass made of?

Back 20

1/2 sand
1/4 old broken glass
Soda
Lime
Soda ash Other small components

Front 21

Name 4 types of glass and how each breaks & relative strengths.

Back 21

Annealed - sharp shards
Heat-strengthened - sharp shards. 2x annealed.
Laminated - shards held together in sheet. <annealed.
Tempered - small round or square pieces. 4x annealed.

Front 22

How is tempered glass made?

What is the main advantage over annealed glass?

Back 22

Outside is cooled quickly - in compression
Inside cooled more slowly - in tension.

Tempered glass is 4 x stronger than annealed.

Front 23

Glazing used for cladding can be ____________ or __________ glass.

Back 23

Spandrel or vision.

Front 24

Tinted glass can reduce ____________ but not __________.

Clear glass transmits ______% of light.
Very dark tinted glass transmits ______% of light.

Back 24

Light, heat

85%
14%

Front 25

What is the measure of energy conserving potential of glass?

Describe high and low K glass.

Back 25

Luminous efficacy, Ke

High K => blocks heat but not light.
Low K => blocks both, mirrored glass

Front 26

1. How much reduction in heat transfer occurs with
Double glazing and Triple glazing
2. What separates the layers in double glazing?
3. Instead of air, what? How much improvement?

Back 26

1. 50% of heat passes, 33% of heat passes
2. Spline (and sealant)
3. Argon or Krypton, 12-18% improvement

Front 27

What does low-E stand for?
How does low-E glass work?

Back 27

Low emissivity
Thin transparent metallic coating. Blocks UV + IR light. IR is heat source. Passes visible light.

Front 28

When roof insulation is placed between the membrane and the deck, "______________ vents" are needed to prevent insulation decay and membrane blisters.

Back 28

topside

Front 29

From top to bottom, the correct order of elements in a protected membrane roof are ballast, membrane, insulation and deck.
TRUE or FALSE

Back 29

FALSE

Front 30

Which one of the following methods for creating roof slope is NOT suitable for large, expansive roofs?
a. Roof structure contains slope (truss)
b. Sloped concrete screed
c. Tapered insulation
d. All e. None

Back 30

a. Roof structure contains slope (truss)