14 Energy Conservation and Air Quality Flashcards
1
Q
What major change in energy costs occurred in the 1970s?
A
Energy costs went through the roof.
2
Q
What is the thermal envelope?
A
The insulated layer between inside and outside of a house.
3
Q
What problems can arise from tightening the thermal envelope?
A
- Excessive interior moisture
- Peeling paint
- Moldy walls
- Buildup of pollutants
4
Q
What is back-drafting in home ventilation?
A
Exhaust gases being pulled back down the chimney due to negative pressure.
5
Q
Name two websites focused on green building.
A
- www.GreenBuildingAdvisor.com
- www.BuildingGreen.com
6
Q
What are the three ways heat is transferred?
A
- Radiation
- Conduction
- Convection
7
Q
Fill in the blank: Heat loss through wood framing is known as _______.
A
thermal bridging
8
Q
What is the R-value in insulation?
A
A measure of a material’s resistance to heat transfer.
9
Q
What is the primary function of air barriers?
A
To make air barriers continuous and airtight.
10
Q
True or False: Most insulation completely stops airflow.
A
False.
11
Q
What is the first step in a nine-step energy retrofit?
A
Get an energy audit.
12
Q
What can an energy audit identify?
A
- Air leaks
- Energy rating
- Annual energy use and costs
13
Q
What should be done before insulating a house?
A
Seal air leaks.
14
Q
How can stale air buildup be remedied after sealing air leaks?
A
By adding a whole-house exhaust fan.
15
Q
What is a heat-recovery ventilator (HRV)?
A
A system that uses stale exhaust air to temper fresh incoming air.
16
Q
Why is insulating the attic or roof effective?
A
Hot air rises, making attic insulation crucial.
17
Q
What should be done before insulating basement walls?
A
Correct moisture problems first.
18
Q
What type of insulation is suggested for basement walls?
A
Rigid-foam panels.
19
Q
What is one cost-effective way to insulate walls?
A
Blowing in dense-pack cellulose.
20
Q
What is a more affordable alternative to replacing all windows?
A
Weatherstrip existing windows and install low-e storm windows.
21
Q
What is the cost range for installing a high-efficiency furnace?
A
$4,000 to $6,000.
22
Q
What is one way to supplement an existing HVAC system?
A
Install solar hot water or photovoltaic panels.
23
Q
What is a key factor in making air barriers effective?
A
Sealing the seams and gaps of materials.
24
Q
What should homeowners do to reduce energy bills incrementally?
A
Plan, be patient, and pay as they go.
25
How can air infiltration in old houses be predicted?
It typically occurs in predictable places like attic floors.
26
What is the primary cause of energy loss in homes?
Air infiltration
27
What are common areas where old houses leak air?
* Attic floors
* Windows
28
What has increased the need for scientific audits in building science?
Rising energy prices and regulations
29
Where can renovators find information on energy rebates and incentives?
Department of Energy’s website, www.energy.gov
30
What is the purpose of the Energy-Efficient Mortgage Program?
To encourage lenders to provide mortgage credit to borrowers who may not qualify otherwise
31
What is blower-door testing used for?
To quantify the volume of air being lost through leaks
32
How does a blower door operate?
It depressurizes the house to pull outside air in through holes in the thermal envelope
33
What does a manometer measure during blower-door testing?
Pressure differences between inside and outside
34
What is the significance of a pressure difference of 50 pascals (Pa)?
It is a standard reference basis for blower-door testing
35
What tools can be used alongside blower-door testing to pinpoint leaks?
* Smoke pencils
* Thermal imaging
36
What do smoke pencils do during an energy audit?
They make individual air leaks visible
37
What is thermal imaging used for in energy audits?
To identify heat loss, air leaks, insulation issues, and moisture problems
38
What percentage of lost energy can leaky ducts account for?
Up to 30%
39
What is the first step in duct testing?
Temporarily sealing heat registers and supply grilles
40
What can be a serious risk of leaky ducts near combustion appliances?
Negative pressure can pull dangerous flue gases into living spaces
41
What is included in a thorough audit regarding combustion appliances?
Testing for efficiency and safety, including gas leaks
42
What do digital combustion analyzers assess?
The efficiency of heating and cooling appliances
43
What do HERS ratings indicate?
A home's energy efficiency along a continuum from 0 (net zero) to higher values
44
What kind of recommendations do skilled auditors provide?
Specific suggestions for improving efficiency, safety, health, and comfort
45
How can homeowners find a reputable energy auditor?
Ask trusted building professionals or check databases of certified auditors
46
What is a potential conflict of interest when hiring an auditing-contractor company?
The company doing the work may not be an unbiased auditor
47
True or False: Energy audits are not necessary for older homes.
False
48
Fill in the blank: The _______ is a widely used home energy rating system.
HERS-II
49
What is the advantage of hiring a combined auditing-contracting company for energy retrofits?
It simplifies the process for homeowners by overseeing the retrofit and managing government incentives
## Footnote
One contact point for issues increases accountability.
50
What is the role of air sealing in insulation effectiveness?
Most insulation achieves its full R-value only when used with an air barrier, preventing conditioned air escape
## Footnote
Air leaks can significantly hinder insulation performance.
51
What percentage of energy losses can air infiltration account for in homes?
20% to 30%
## Footnote
This is particularly true for homes with fiberglass batts or cellulose insulation.
52
What is the best term to describe materials that stop air infiltration?
Sealants
## Footnote
Caulk is a common type of sealant used for building gaps.
53
What type of caulk is best for gaps less than 1/2 inch wide?
Caulk
## Footnote
For wider gaps, a foam backer rod should be used first.
54
What are the main categories of caulks?
* Water-based caulks
* Silicone-based caulks
* Synthetic-rubber caulks
* Modified silicone polymer caulks
## Footnote
Each category has specific applications and benefits.
55
True or False: Silicone-based caulks can be painted.
False
## Footnote
Pure silicone cannot be painted, but siliconized acrylics can.
56
What are fire-blocking caulks and foams used for?
To fill penetrations that may allow heat and flames to spread in the event of a fire
## Footnote
They expand when exposed to superheated air.
57
What is the primary use of polyurethane foam sealants?
To fill gaps and seal air leaks
## Footnote
They are typically applied using aerosol cans.
58
What should be done before applying foam sealants?
Ensure surfaces are stable and reasonably free of debris
## Footnote
Foam sealants don’t require as strict surface prep as caulks.
59
What is the best sealant for gaps that will experience movement?
Weatherstripping
## Footnote
It is ideal for sealing around attic hatches and bulkhead doors.
60
What is the purpose of foam outlet and switch plate gaskets?
To quickly seal beneath cover plates of electrical receptacles and switches
## Footnote
They help prevent air leaks.
61
What are the two brands of sprayable caulks mentioned?
* EnergyComplete™
* EcoSeal™
## Footnote
These are designed for sealing seams before insulation is installed.
62
What effect does the 'stack effect' have on attics?
It causes warm air to rise, making attics a key area for air sealing
## Footnote
This is critical for energy efficiency.
63
What should be done to the attic hatch to improve insulation?
Insulate it or build an insulated cover
## Footnote
Use rigid-foam panels and weatherstripping for sealing.
64
What is a safe way to handle chimney gaps according to building codes?
Pack the gap with noncombustible material and cover it with sheet metal
## Footnote
This prevents air leaks while maintaining safety.
65
What is the recommended action for old bath fan boxes?
Seal fan-box flanges to the ceiling with caulk or foam
## Footnote
Ensure fan exhausts outside to prevent moisture issues.
66
What type of recessed ceiling lights are big energy leakers?
Old, non-IC-rated cans
## Footnote
They cannot be covered with insulation.
67
What is the best way to seal non-IC-rated ceiling cans?
Replace them with IC-rated ones
## Footnote
This is safer and more cost-effective.
68
What should be done if knob-and-tube wiring is still active?
Do not spray it with foam sealant or cover it with insulation
## Footnote
Call a licensed electrician for replacement.
69
What is the purpose of placing rigid foam along the attic perimeter?
To prevent heat loss and air leaks
## Footnote
It helps insulate the top plates.
70
What is the recommended action for sealing gaps in electrical boxes?
Make a quick pass with spray foam
## Footnote
Avoid filling the box itself to comply with electrical codes.
71
What is the importance of surveying for air leaks in the attic?
To identify and seal penetrations effectively
## Footnote
Discolored insulation can indicate air leakage.
72
What should be done for gaps between the roof and wall in attics?
Spray foam should be used to seal areas where ceiling drywall meets exterior walls
## Footnote
This is especially important for energy efficiency.
73
What should be done to caulk panel edges when installing foam panels along the attic perimeter?
Use caulk or expanding foam for a tight seal.
74
What may block air coming up from eave vents when insulation is pushed tight to exterior walls?
Insulation blocking.
75
What product can be installed to contain insulation and prevent blocking eave vents?
Baffle/air chute such as AccuVent®.
76
What should be sealed and insulated in a finished attic with kneewalls?
The back side of the walls facing the exterior.
77
What is more effective in reducing energy loss compared to fiberglass batts?
Rigid foam.
78
What is the first essential step to achieve airtight windows and doors?
Correct flashing.
79
What is a cost-effective alternative to replacing windows?
Installing storm windows.
80
What can be used to quickly seal receptacles and switches on exterior walls?
Compressible foam gaskets.
81
What type of caulk is recommended for sealing room junctures during painting?
Water-based latex or acrylic caulk.
82
What is a common material used for caulking a building's exterior seams?
Synthetic rubber or modified silicone caulking.
83
What should be used to seal gaps around window and door jambs?
Minimally expanding foam.
84
What should be done to shared walls with an attached garage?
Use fire-rated caulks or fire-rated foams.
85
What should be done if blower-door testing indicates a leaky fireplace damper?
Attend to sealing the fireplace damper.
86
What insulation type can simultaneously air-seal and insulate joist bays in a basement?
Open-cell spray foam insulation.
87
What is the most cost-effective way to seal rim joists in a basement?
Cut and fit pieces of rigid-foam insulation.
88
What material should be used to seal cracks and gaps in concrete basement walls?
Masonry caulk or compatible expanding foam.
89
What should be done with inoperable basement windows?
Seal shut with expanding foam.
90
What should be used to seal holes around pipes and wiring in the basement?
Expanding foam.
91
What is the proper method to secure duct joints?
Screw and tape duct joints and fittings.
92
What is the correct tape to use for sealing duct joints?
Aluminum duct tape.
93
What should be applied to hand-snipped and swivel joints in ductwork?
Fiber-reinforced mastic.
94
What are vapor retarders commonly referred to as?
Vapor barriers.
95
How is permeability measured in vapor retarders?
In perms.
96
What materials are classified as Class I vapor retarders?
Polyethylene sheeting, rubber membranes, sheet metal, aluminum foil.
97
What class of vapor retarders includes oil-based paint and kraft-paper facing?
Class II (semi-impermeable) vapor retarders.
98
What is the issue with using polyethylene vapor barriers in warm climates?
They can trap moisture in walls.
99
What is the Airtight Drywall Approach used for?
To stop air leaks and the movement of moisture into walls.
100
What ventilation area is required per 300 sq. ft. of attic space?
1 sq. ft. of vents.
101
What is Joe Lstiburek's recommended ventilation split for eaves and ridge vents?
A 60/40 split, with more ventilation at the eaves.
102
What is a significant energy loss area in vented attics?
Where roof slopes meet sidewalls.
103
What should be installed over wall sheathing to reduce energy loss?
Rigid insulation.
104
What is the purpose of air-sealing and piling insulation over top plates?
To reduce energy loss in walls without blocking soffit vents.
105
What can be installed over wall sheathing to reduce energy loss?
Rigid insulation.
106
Why is installing rigid insulation over wall sheathing considered a prohibitively expensive fix?
Unless siding needs to be stripped for another reason.
107
What is essential to keep air flowing from the soffit to the ridge?
Preventing attic insulation from covering the vent to the exterior.
108
What materials are typically used to ensure airflow in attics?
Rigid foam and combination baffles/air chutes.
109
What is the venting path for roofs?
Air flows up from the eaves and out at the ridge.
110
What is the IRC's requirement for airspace under roof sheathing?
1 inch of airspace.
111
What does Joe Lstiburek recommend for airspace under roof sheathing?
2 inches of airspace, minimum.
112
What is the fastest way to create a vent channel under the roof deck?
Installing a prefabricated vent baffle.
113
What is the most affordable way to insulate under the roof if the roof is in good shape?
Conventional insulation methods.
114
Which type of insulation provides the greatest R-value per inch?
Closed-cell spray polyurethane foam.
115
What are the options if rafters are not deep enough for insulation?
Spray-foam insulation, batts between rafters, or furring out rafters.
116
What is a built-up roof composed of?
2x4 purlins, foam panels, and vertical 2x4 spacers.
117
When is an unvented roof often the only viable option?
When roof framing is complicated or there are no soffits.
118
Why might unvented roofs make sense in high-wind or high-fire areas?
Vents might admit drenching rains or embers.
119
What is the most straightforward route for insulation on complex roofs?
Spraying closed-cell polyurethane foam on the underside of the roof deck.
120
What might be required for unvented roofs in the snow belt?
Some type of venting to keep the roof cold and prevent ice dams.
121
What can happen if shingles are installed over unvented roofs?
Some roofing manufacturers may not honor warranties.
122
What is essential to add after air-sealing a house?
Controlled ventilation.
123
What are the two types of ventilation mentioned for exhausting stale air?
Mechanical ventilation (fans) and natural convection.
124
What is the benefit of soffit-to-ridge ventilation?
It effectively exhausts moisture and cools the area under a roof.
125
How does cool incoming air help in winter?
It can prevent snowmelt and ice dams along eaves.
126
What temperatures can unvented roofs reach in summer?
150ºF to 160ºF.
127
What is an AccuVent?
A baffle and air chute that restrains attic insulation
128
What is the purpose of baffles in an attic?
To keep insulation from clogging vent holes and ensure air flow
129
What is the recommended method for sealing baffle edges?
Seal baffle edges with expanding foam
130
Why is soffit-to-ridge ventilation important?
It can prolong shingle life and cool upper-floor rooms
131
What is the recommended length of baffles needed for a 30-ft. by 40-ft. attic?
Roughly 80 linear feet of baffles
132
What material is AccuVent made from?
Recycled plastic
133
What is the primary function of a whole-house exhaust fan?
To ventilate the whole house continuously
134
What is the typical air flow rating for a small exhaust fan?
50 cfm
135
What is the estimated annual operating cost of a 15-watt Energy Star fan running 8 hours a day?
Less than $10
136
What should be installed to avoid backdrafting when using an exhaust fan?
Two or three passive intake vents
137
What is the rule of thumb for sizing bath fans in bathrooms 100 sq. ft. and smaller?
1 cfm per square foot
138
What feature is important for bathroom fans to continue venting after leaving the room?
An electronic switch with an integral timer
139
What should be used to seal duct joints for a bathroom fan?
Foil duct tape
140
What is the recommended practice to reduce moisture condensation in bathroom-fan ducts?
Insulate the ducts and keep runs short
141
How should the roof vent for a bathroom fan be flashed?
Feed its upper flange under the shingle courses above and over the courses below
142
What is a heat-recovery ventilator (HRV) used for?
To recover heat from outgoing air to temper incoming fresh air
143
What is the typical recovery rate of heat in an HRV system?
75% to 80%
144
What are common sources of excessive interior moisture?
* Air infiltration
* Poorly installed roofing
* Improper surface drainage
* Unsealed crawlspaces
* Inadequately vented areas
* Leaking HVAC ducts
145
What is the primary source of interior moisture in homes?
Kitchens and bathrooms
146
What should be done to seal crawlspaces effectively?
Address improper surface drainage and ensure gutters are clear
147
Fill in the blank: The best way to thwart the growth of mold is to exhaust excess moisture—send it _______.
outdoors
148
True or False: Remote inline fans are quieter because they are located in the bathroom.
False
149
What type of fan can vent two bathrooms with one motor?
Remote fan
150
What is the primary cause of wetness in crawlspaces or basements?
Improper surface drainage, especially clogged gutters and downspouts.
151
How much vent space is typically prescribed for crawlspaces?
1 sq. ft. of screened vents for each 150 sq. ft. of dirt floor, or 1 sq. ft. of vents for every 1,500 sq. ft. of floors covered with a moisture barrier.
152
What are the consequences of open crawlspaces during winter and summer?
Cold floors and heat loss in winter; warm, moist air entering in summer, leading to condensation and mold.
153
What is the recommended thickness of polyethylene for a moisture barrier in crawlspaces?
6-mil polyethylene is minimal; 20-mil polyester cord–reinforced sheeting is preferred.
154
What material is suggested for sealing vent openings in crawlspaces?
2-in.-thick EPS foam panels.
155
What should you do if moisture persists in a sealed crawlspace?
Insulate the walls with EPS foam panels or spray foam insulation.
156
What personal protective equipment is recommended when cleaning up mold?
Respirator mask with N95 filters, rubber gloves, eye protection, and disposable coveralls.
157
True or False: Mold can grow without moisture.
False.
158
What should you do with contaminated materials during mold remediation?
Seal damaged materials in plastic before transporting them from the site.
159
What is the first step in mold remediation?
Identify and correct the source(s) of excess moisture.
160
What type of insulation accounts for three-quarters of residential insulation sales?
Fiberglass batts.
161
What are the five groups of insulating products?
* Batts
* Loose fill
* Dense pack
* Rigid-foam panels
* Spray foam
162
What is R-value a measure of?
Insulation's ability to resist heat traveling through it.
163
What is a common problem with installing batt insulation in older houses?
Irregular framing can lead to gaps or thin spots in insulation.
164
What is the recommended action for moldy drywall?
Cut back the drywall at least 1 ft. beyond the damaged area and replace it.
165
What is the recommended thickness for cotton batts?
Formaldehyde-free and itchless, made from recycled cotton.
166
How should surface mold be cleaned?
Wash with soap and water and let it dry well.
167
Fill in the blank: Fiberglass batts should be installed precisely to fill cavities between framing members without _______.
gaps or thin spots.
168
What should be done to limit exposure to mold spores during cleanup?
Wear protective gear and seal off affected areas.
169
What is the ideal moisture content for framing before installing new drywall?
15% to 20% or less.
170
What should be done with moldy lumber and engineered wood products?
Probe them to see how sound they are; if spongy, replace them.
171
What type of insulation is often used to retrofit unfinished attics?
Loose-fill insulation.
172
What is the purpose of using a commercial-grade vacuum with HEPA filters during mold remediation?
To limit the spread of mold spores.
173
What is the insulation requirement for Zone 1?
Hawaii, Guam, Puerto Rico, Virgin Islands
## Footnote
Zone 1 includes these specific regions.
174
Which boroughs in Alaska are in Zone 8?
Bethel, Northwest Arctic, Dellingham, Southeast Fairbanks, Fairbanks N. Star, Wade Hampton, Nome, Yukon-Koyukuk, North Slope
## Footnote
These boroughs are exceptions in the context of insulation zones.
175
What is the R-value range for loose-fill fiberglass insulation?
2.2–2.7 per inch
## Footnote
This R-value indicates its insulating effectiveness.
176
To achieve an R-49 rating with loose-fill fiberglass, how thick should the insulation be?
Approximately 19 inches
## Footnote
This thickness is necessary for optimal insulation.
177
True or False: Loose-fill cellulose absorbs water and dries quickly.
False
## Footnote
Cellulose retains water and dries slowly, which can be a disadvantage.
178
What is the R-value of open-cell polyurethane foam?
3.6 per inch
## Footnote
This R-value is comparable to fiberglass batts or loose-fill cellulose.
179
What does dense-pack insulation involve?
Blowing insulation into confined spaces at higher pressures
## Footnote
It requires trained specialists for proper installation.
180
What is the main advantage of using rigid-foam insulation panels?
They reduce air and moisture infiltration and eliminate heat loss
## Footnote
This makes them effective for energy retrofits.
181
What is the R-value of polyisocyanurate (polyiso) insulation?
Initial R-value of 7.4 per inch, residual R-value of 6.5 per inch
## Footnote
Polyiso is noted for its high effectiveness.
182
Fill in the blank: The deeper the framing members, the thicker the _______ foam must be.
open-cell
## Footnote
This is due to its lower R-value requiring more material.
183
What type of insulation is commonly used for air-sealing attics?
Spray polyurethane foam
## Footnote
SPF is effective due to its expansion and adherence properties.
184
What is the R-value of expanded polystyrene (EPS) insulation?
R-4 per inch
## Footnote
EPS is known for being the least expensive among rigid foams.
185
What should be done to prepare an attic before adding insulation?
Air-sealing the attic and covering large holes
## Footnote
This ensures effectiveness and prevents issues with insulation.
186
What is the primary disadvantage of using cellulose insulation?
It absorbs water and dries slowly
## Footnote
This can lead to problems if there are leaks.
187
What is the perm rating of closed-cell foam?
Less than 1
## Footnote
This makes it suitable for exterior applications as a vapor retarder.
188
What is the recommended density for dense-pack cellulose insulation?
3 lb./cu. ft.
## Footnote
This density helps stop air infiltration.
189
True or False: Loose-fill fiberglass is denser than cellulose.
False
## Footnote
Cellulose is denser and less air-permeable than fiberglass.
190
What is the compressive strength of polyisocyanurate compared to other rigid foams?
Lowest compressive strength
## Footnote
It is still effective due to its high R-value.
191
What is a significant feature of spray polyurethane foam when applied correctly?
It is inert, nonoff-gassing, and odorless
## Footnote
This makes it safe for both interior and exterior applications.
192
What type of insulation is often favored for finishing basement walls?
Expanded polystyrene (EPS)
## Footnote
Its semi-permeable nature allows for moisture migration.
193
What are the key characteristics of Air Krete®?
Air Krete® is formaldehyde-free, mold-resistant, pest-resistant, has good sound-deadening qualities, and attains an R-value of 3.8 per inch
## Footnote
Air Krete® is applied through a fine screen and has good fire-resistance due to its principal ingredient: magnesium oxide.
194
What safety gear is recommended when installing fiberglass batts?
Wear a respirator, eye protection, long-sleeved shirt, long pants, and work gloves
## Footnote
This gear is necessary to prevent fiberglass from irritating skin and lungs.
195
How can you determine how much insulation to buy?
Measure the square footage of walls, ceilings, and floors, then divide by the number of square feet in an insulation package
## Footnote
Check the insulation’s R-value and width on the packaging.
196
What is the common size for fiberglass batts in standard construction?
15-inch wide batts are the most common size
## Footnote
This size fits most joists, studs, and rafters spaced 16 inches on center.
197
When should unfaced batts be installed?
Unfaced batts are preferred when no vapor retarder is required or one will be installed later
## Footnote
They are quicker to install as there’s no facing to cut through.
198
What should you do before insulating attic floors?
Locate electrical boxes and IC-rated recessed lights
## Footnote
Use coat hangers and bright scrap plastic to mark their locations.
199
What is the recommended way to cut fiberglass insulation?
Use a utility knife and make several passes
## Footnote
Professional insulators may use a long-bladed insulation knife for efficiency.
200
What is the benefit of using precut batts?
Precut batts save time on measuring and ensure a better fit
## Footnote
This is especially useful for standard 8-ft. walls.
201
What should be done to prevent cold spots behind pipes and wiring?
Split batts in two and fit each half around the obstruction
## Footnote
This ensures effective insulation without gaps.
202
What is the purpose of air chutes when insulating attics?
Air chutes create a 1-inch space between the sheathing and insulation for air flow
## Footnote
This helps maintain ventilation under the roof.
203
True or False: Unvented roofs can be a good option for houses with complicated roof framing.
True
## Footnote
Unvented roofs eliminate the need for eave-to-ridge ventilation.
204
What should be done when installing loose-fill insulation?
Cover chases and large openings to prevent insulation from blowing everywhere
## Footnote
Additionally, keep the material away from non-IC-rated recessed lighting cans and chimneys.
205
What is a recommended practice when insulating around electrical outlet boxes?
Split insulation batts and slide portions behind the boxes
## Footnote
This helps to stop air leaks effectively.
206
What are the risks of working in an unfinished attic?
Risk of stepping through the ceiling if joists are not properly navigated
## Footnote
Setting up work lights and wearing safety gear is crucial.
207
What is the recommended method for blowing loose-fill insulation into an attic?
Start by blowing insulation into the farthest reaches and work toward the access door
## Footnote
Angling the hose slightly upward helps disperse the insulation evenly.
208
How should batts be placed to ensure they fill joist bays completely?
Cut batts to length and ensure they are plumped up to full thickness
## Footnote
Butt the ends together rather than overlapping.
209
Fill in the blank: When insulating a floor over an unconditioned crawlspace, you need to fight against _______.
gravity and moisture
210
What is a common challenge when insulating floors above basements and crawlspaces?
Gravity and moisture create challenges for insulation stability
## Footnote
Special techniques may be required to hold insulation in place.
211
What is the recommended method to install fiberglass batts in joist bays?
Use precut wood slats or ‘lightning rods’ to hold batts in place while installing.
212
When is rigid-foam panels or spray polyurethane foam preferred over fiberglass batts?
When the subfloor area is damp or during warm months with heavy condensation.
213
What is dense-packing insulation?
A method of blowing insulation into confined spaces at higher pressures.
214
What equipment is necessary for dense-packing insulation?
* Insulation blower
* Hoses
* Respirator mask
* Safety glasses
* Work gloves
215
True or False: Dense packing insulation is a job suitable for DIYers.
False.
216
What precaution should be taken when working with knob-and-tube wiring?
It must not be covered with insulation.
217
What safety measure should be taken regarding insulation blowers?
Keep hands away from the hopper while paddles are turning.
218
What is vermiculite and why is it a concern?
A mineral fiber sometimes containing asbestos, requiring professional removal.
219
What type of hose is typically used for blown-in insulation?
A 3-in. corrugated plastic hose.
220
What should be done if a hose clogs during insulation installation?
Remove the reducing nozzle and turn on the blower to clear the clog.
221
What is the preferred method for plugging holes after insulation installation?
Use beveled plugs or corks with exterior-grade glue.
222
What is the modern approach to moisture migration in exterior walls?
Use semipermeable materials that allow moisture to dry to the inside.
223
What is the first step in creating a dry basement with EPS panels?
Attend to sources of exterior water before remodeling.
224
How thick should EPS panels be when installed on basement floors?
1-in.-thick EPS panels.
225
What is the purpose of using paperless drywall over insulated walls?
To prevent mold and wood rot while meeting fire-retardant code requirements.
226
What is the R-value of closed-cell spray polyurethane foam (SPF) per inch?
6.5 per inch.
227
What is a significant advantage of spray-foam roofing?
It can be applied directly over the old roofing without stripping it.
228
What does a Class II water retarder mean in the context of closed-cell SPF?
It creates a semi-impermeable membrane that prevents leaks.
229
Fill in the blank: The easiest way to install fiberglass batts without needing three hands is to precut a number of thin wood slats—_______.
1⁄4-in. longer than the distance between the joists.
230
What method is suggested for sealing gaps around EPS panels?
Use low-expanding foam around the perimeter.
231
What is a significant environmental benefit of not stripping the old roof?
It prevents debris from being sent to the landfill
## Footnote
This practice contributes to green building initiatives.
232
What is the function of four inches of closed-cell polyurethane?
It serves as a class II water retarder, making leaks nearly impossible
## Footnote
This semi-impermeable membrane helps seal pipes and conduits.
233
Why was the flat roof of a 1957 Eichler-designed house a good candidate for a polyurethane spray-foam roof?
It provided no cavity under the sheathing for hiding pipes
## Footnote
This design feature makes foam application more effective.
234
How does the cost of an SPF roof compare to a new torch-down roof or PVC membrane?
An SPF roof is less expensive than installing and insulating those alternatives
## Footnote
This comparison does not include the cost of stripping the old roof.
235
What energy-efficiency incentives were available for installing an SPF roof?
Energy-efficiency rebates
## Footnote
However, the couple was too busy to take advantage of these rebates.
236
Is spray polyurethane foam considered a green choice?
Yes and no, but mostly yes
## Footnote
The insulation industry has improved since the early days of sprayed foam.
237
What are the chemical components of SPF primarily based on?
Petroleum
## Footnote
Once cured, it is chemically inert and does not offgas.
238
What is a major advantage of not sending old roofing to the landfill?
It contributes to environmental sustainability
## Footnote
The excellent R-value of the material also adds value.
239
How can an SPF roof be made more durable?
By spraying it with a special acrylic top coating
## Footnote
This protects the foam from UV degradation.
240
What is the reflective property of the foam's light color?
It reflects sunlight, contributing to a cooler roof
## Footnote
This can enhance energy efficiency.
241
What preparation is necessary before spraying foam?
Electrical conduits must be raised for accessibility
## Footnote
This is crucial to prevent them from being covered by foam.
242
Why is it important to mask areas not intended for foaming?
Spray foam adheres aggressively
## Footnote
Proper masking prevents unwanted foaming on surfaces.
243
What is the strength characteristic of closed-cell foam once cured?
It is strong enough to walk on
## Footnote
This adds to its practicality for roof applications.
244
What must be ensured about the old roof before applying polyurethane foam?
The old roof must be clean and well attached
## Footnote
This ensures proper adhesion of the new foam layer.
245
Fill in the blank: The polyurethane foam expands to seal everything sticking out of the roof, including _______.
pipes and conduits
246
True or False: The polyurethane foam can be sprayed directly over any type of existing roof.
False
## Footnote
The old roof must be clean and well attached for effective application.
