Module 2 Section 2 Insulation/Ventilation Study Cards

Question 1

The primary function of insulation is to__

Answer 1

control heat loss

Question 2

A vapor retarder is designed to__

Answer 2

restrict vapor diffusion

Question 3

What are the implications of an inadequate air/vapor barrier

Answer 3

moisture may get into the building structure, causing damage

Question 4

Name 2 purposes of house ventilation

Answer 4

1. flushes moisture from unconditioned spaces in winter & heat from these spaces in summer
2. provides fresh air for building occupants

Question 5

Relative humidity

Answer 5

the amount of moisture in the air relative to the amount it could hold if saturated, expressed as a percent

Question 6

drying potential

Answer 6

ability of a material or assembly to dry out after it has gotten wet

Question 7

Why are roofs vented in the winter in cold climates?

Answer 7

We were not able to completely to stop air leakage into cool roof spaces, so we need to get rid of that warm, moist air.

Question 8

Purpose of a heat recovery ventilator:

Answer 8

To transfer some of the heat from the air exhausted from the house into the fresh air coming into the house

Question 9

Term ventilation might mean 2 very different things with respect to homes. 2 different types of ventilation:

Answer 9

1. venting of roof & wall spaces to flush warm moist air out of the building components
2. exhausting stale air & supplying fresh air to the living spaces

Question 10

Indicate where the air/vapor barrier should be located in the wall assembly in a hot, humid climate.

Answer 10

outer part of wall, or not at all

Question 11

4 common forms that insulation materials may be found in:

Answer 11

1. loose fill
2. batts or blankets
3. rigid boards
4. foamed-in-place

Question 12

10 common insulation materials:

Answer 12

1. fiberglass 6. extruded polystyrene
2. cellulose fiber 7. closed cell phenolic plastic
3. mineral wool 8. polyisocyanurate
4. vermiculite/perlite 9. polyurethane
5. expanded polystyrene 10. isocyanate/polyisocyanate

Question 13

What forms do insulation materials come in?

Answer 13

loose, fill, batt, board
loose fill
board
foamed in place

Question 14

Function of an air barrier:

Answer 14

to stop air movement through building walls/roofs

Question 15

Indicate 2 reasons we are interested in controlling air movement through building walls and roofs.

Answer 15

1. minimize heat flow to exterior/interior
2. minimize moisture flow to building components

Question 16

Describe the function of a vapor barrier

Answer 16

protect building from moisture damage. designed to protect from moisture due to vapor diffusion, not air movement

Question 17

2 other names for vapor barriers:

Answer 17

vapor retarder, vapor diffusion retarder

Question 18

Is it more important for the air barrier or vapor barrier to be continuous?

Answer 18

air barrier

Question 19

Should the vapor barrier be on the warm side or cold side of the wall assembly?

Answer 19

warm side

Question 20

Should the vapor barrier be on the warm side or cold side of the wall assembly in a hot, humid climate?

Answer 20

warm side

Question 21

3 functions of roof vents:

Answer 21

1. allow warm, moist air out of attic
2. reduce attic temps in summer
3. helps prevent ice dams in winter by keeping attic cold

Question 22

4 types of roof vents:

Answer 22

1. soffit
2. ridge
3. roof
4. gable

Question 23

Percentage of total venting should be at soffits?

Answer 23

50%

Question 24

Percentage of total venting should be high on roof?

Answer 24

50%

Question 25

When can soffit venting be omitted safely?

Answer 25

If there are gable vents at opposing ends

Question 26

What do soffit vents baffles do?

Answer 26

prevent insulation from covering the vents

Question 27

How are mansard or gambrel roofs ideally vented?

Answer 27

1. required a ridge & bottom of upper section 2. none is required for steep section

Question 28

Is it possible to over-ventilate an attic? If so, why is this an issue?

Answer 28

1. Yes, if ceiling is not well sealed 2. can cause negative pressure in attic that promotes warm, moist air to enter at a faster rate

Question 29

What should you wear when inspecting attics? (3 things)

Answer 29

1. mask 2. goggles 3. long sleeves with tight cuffs

Question 30

List 3 things that may make attics dangerous:

Answer 30

1. fall through ceiling 2. electric shock 3. irritate lungs

Question 31

4 common access hatch problems & the implications of each:

Answer 31

1. not insulated: results in heat loss 2. not weather stripped: results in heat loss & air leakage 3. missing: results in heat loss & air leakage 4. inaccessible: limits inspection

Question 32

What are the implications of insulation that is only 2 inches thick, wet, compressed, interrupted by gaps or voids, or missing?

Answer 32

1. 2" thick: heat loss 2. wet: won't work well/damage to finishes 3. gaps/folds: localized heat loss, ice damming 4. compressed: reduced R-value 5. missing: heat loss, ice damming

Question 33

Under what circumstances should insulation cover recessed lights? What is one inspection strategy to help identify recessed lights while in the attic?

Answer 33

only if lights are proper type, or installed in drywall boxes; look for double shell, or IC stamp

Question 34

Will you ever see walls in attics? Where? Should they be insulated?

Answer 34

Walls indicate skylights or light wells; yes, should be insulated

Question 35

What 2 things should you be looking for on ducts in attics?

Answer 35

1. insulation 2. air/vapor barrier

Question 36

How should insulation be handled around masonry chimneys?

Answer 36

Masonry chimneys should only have noncombustible insulation surrounding them.

Question 37

How should insulation be handled around metal vents?

Answer 37

Vent is contained in a boxed-in area to keep insulation away

Question 38

What are the implications of air/vapor barriers that are missing or incomplete?

Answer 38

1. air leakage 2. rot damage 3. insulation gets wet from condensation

Question 39

3 common problems with roof vents & implications:

Answer 39

Problem: birds nests-implication: inadequate venting Problem: mechanical damage-implication: mold/rot

Question 40

What is suggested by snow on attic insulation below roof vents?

Answer 40

If soffit venting is missing, rain & snow may actually be drawn into the roof vents

Question 41

3 possible concerns with turbine vents:

Answer 41

No ventilation on calm days; too much ventilation; too much ventilation on windy days; noisy or seized

Question 42

Should power vents be operating in the winter? Why or why not?

Answer 42

No, they can depressurize the attic, increasing heat loss

Question 43

What is suggested by mold or rot on rafters & sheathing?

Answer 43

an exhaust fan dumping warm, moist air directly into the attic

Question 44

Describe is one sentence, 4 general approaches to insulating flat & cathedral roofs

Answer 44

Treat as an attic-w/a little insulation & an air space Completely fill roof space-in theory it stops air flow Insulate above sheathing-roof membrane applied over insulation Insulate below roof structure-lowers ceiling heights, but provides good ventilation

Question 45

5 common problems found with flat rood insulation systems.

Answer 45

1. too little insulation 2. wet, compressed or voids 3. missing or incomplete air/vapor barrier 4. missing or inadequate venting 5. venting obstructed

Question 46

Implications of problems with flat roof insulation systems:

Answer 46

1. heat loss, no damage to structure 2. reduced R-values, mold/mildew/rot 3. mold/mildew/rot 4. warm, moist air condensing & cause mold/mildew/rot 5. mold/mildew/rot

Question 47

One possible way to get a look at insulation in a flat roof.

Answer 47

1. remove ceiling light fixture or exhaust fan covers; 2. pop fascia vents off & look through holes

Question 48

What things might suggest wet insulation:

Answer 48

staining; sponginess or dampness on ceilings

Question 49

Describe 2 strategies used to deal w/venting of flat roofs:

Answer 49

1. vent roof space 2. seal roof cavity

Question 50

On a flat roof, where will you most often see vents?

Answer 50

opposing fascias

Question 51

Appropriate ratio of vent area to roof area:

Answer 51

One square foot of venting for every 150 sqft of roof area

Question 52

Basement wall insulation is necessary. T/F

Answer 52

False

Question 53

In 2 sentences each, 2 strategies for insulating basement walls.

Answer 53

Outside-keeps walls warm, no interior space lost, no interior living space lost, etc, but but only certain types of insulation are suitable Inside-inexpensive, can be done at anytime, any type of insulation is suitable, can be difficult to detect leaks.

Question 54

Describe in one sentence each, 2 general approaches to insulating crawl spaces.

Answer 54

1. insulate walls, creating a conditioned crawlspace 2. insulate floor above, creating an unconditioned crawl space

Question 55

All crawl spaces should be vented. T/F Explain

Answer 55

True if unheated-vent to outdoors to remove warm, moist air in cold climates.

Question 56

List 3 safety issues involved in inspecting crawlspaces.

Answer 56

1. wet floors 2. animals 3. dark & dirty

Question 57

List 9 common problems w/insulation & ventilation in basement & crawlspace areas.

Answer 57

1. insulation-too little/incomplete 2. exterior insulation not suitable for below grade use 3. exterior insulation not protected at top 4. insulation missing at rim joists 5. insulation sagging, loose or voids 6. exposed combustible insulation 7. air/vapor barrier missing, incomplete or wrong location 8.no moisture barrier on basement walls 9. no moisture barrier on earth floor

Question 58

List the implications of crawlspace problems:

Answer 58

1. higher heating/cooling costs 2. lower R-value due to moisture 3. mechanical damage from lawn mowers, lawn equipment 4. increased heating cost 5. risk of fire 6. wet insulation, reducing R-value

Question 59

2 possible strategies for keeping floors over unheated spaces warm:

Answer 59

1. heated cavity between floor & insulation below 2. spray-in-place foams that fill entire cavity

Question 60

List 7 areas where floors over unheated spaces may feel cool:

Answer 60

1. above garage 2. above porch 3. cantilevered areas 4. over breezeway 5. over unheated crawl space 6. over open areas 7. below windows projecting out from building