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Home Energy Guide your source for keeping your home comfortable, safe, durable, and efficient August 2018 DIVISION OF ENERGY RESOURCES
The Minnesota Department of Commerce
Division of Energy Resources is working to move
Minnesota toward a sustainable energy future,
managing energy assistance funds and ad-
vocating in the public interest on energy
utility rates and facility siting. We provide
information and assistance on energy conserva-
tion, energy efficiency, and renewable energy
options to residents, builders, utilities, non-
profit organizations, and policy-makers on
building improvements, financial assistance,
renewable technologies, policy initiatives, and
utility regulations. This consumer energy guide
was produced, in part, with funding from the
U.S. Department of Energy. Design, writing,
illustrations, and editing by Division of Energy
Resources staff.
August 2018
DIVISION OF ENERGY RESOURCES
85 7th Place East, Suite 280
Saint Paul, MN 55101-2198TABLE OF CONTENTS 1
Saving Energy...................................... 2 Powering your Home....................... 42
Air-Sealing........................................... 6 Home Ventilation.............................. 44
Home Tightening............................. 6
Attic Air Leaks.................................. 7 Water Heating.................................... 46
ELECTRONICS
Basement Air Leaks.......................... 9 Water Heater Options.................... 46 5%
Exterior Sealing............................... 10 Water Heater Repairs and LIGHTING
10%
Maintenance.................................... 48
Fireplaces......................................... 10
When to Replace............................. 48 APPLIANCES
Caulking........................................... 11
15%
Spray Foam for Large Gaps.......... 12
Thermostats........................................ 50
WATER HEATING
15%
Insulation............................................ 14
Appliances.......................................... 52
Insulation R-values........................ 14
Refrigerators and Freezers............ 52
Attic Insulation............................... 14
Dishwashers.................................... 53 HEATING
Story-and-a-Half............................. 15 AIR CONDITIONING
Laundry........................................... 54 55%
Basement.......................................... 16
Cooktops, Ranges and
Walls................................................. 18
Microwaves..................................... 56
Types of Insulation......................... 20
Lighting............................................... 58
Windows and Doors......................... 21 Home Energy Use
Types of Lighting........................... 58
Window Repairs............................. 21 A typical Minnesota household uses about
Fixtures............................................. 58
Window Replacement................... 22 180 million British Thermal Units (mmBTU)
Bulbs................................................. 59
of energy every year to heat, cool, light, and
Doors................................................ 24
Choosing Lighting.......................... 61 operate appliances and electronics.
Lighting Controls........................... 62 Because one-fifth of the energy consumed
Home Heating.................................... 26
in our state is used in residences, each of us
Furnaces........................................... 26 has the opportunity to affect overall energy
Electronics........................................... 64
Boilers............................................... 29 use and its effects on our environment.
Electric Heating Systems............... 31 This guide is designed to help you improve
Resources............................................ 65
the operation, safety, and comfort of your
Wood and Biomass Systems......... 32
Prework Inspection........................ 65 home and to provide guidance for making
Solar Heating................................... 34
Education and Research................ 65 smart energy efficiency choices.
Heat Pumps..................................... 35
Selecting a Contractor.................... 66
Bids and Contracts......................... 67
Home Cooling.................................... 36
Fans................................................... 37
Air Conditioning............................ 38
Dehumidifiers................................. 412 SAVING ENERGY MAKES GOOD SENSE
How, when, and in what form we use energy can have a dramatic effect on our
lives, our bank accounts, and our environment. Using energy wisely makes
sense and is a goal that we all share.
The average Minnesota family spends a through conservation and efficiency im-
significant amount of money on energy, provements. Even if the annual savings for
but we can dramatically reduce your home are modest, however, they go on,
these costs—up to 30%, according year after year. Many energy improvements
to the U.S. Department of Ener- will save enough money to pay for the initial
gy—by making some simple investment in just a few years—some even
energy-saving improve- sooner!
ments to our homes. In Also, the cumulative effects of thousands of
addition to saving money Minnesota families reducing their energy
on utility bills, we can pro- use will pay big benefits to all of us. We use
tect our homes from mois- a great deal of energy in our state, and the
ture damage year-round, majority of it is derived from fossil fuels—all
reduce problems caused by of which must be imported into our state.
Building Science
ice dams on the roof during the winter, sig- Anything that we can do to reduce the
nificantly cut summer cooling costs, extend emissions from burning coal and petroleum
The interactions of the various the life of houses, and sometimes increase products will help to slow the rate of climate
parts of buildings have become resale values. Furthermore, reductions in en- change and have a positive impact on air
better understood in the past ergy use also reduce environmental effects, and water quality. Additionally, investments
few decades. The efforts of including lowering contributions of carbon in energy-related home improvements help
manufacturers, designers, dioxide and other greenhouse gasses. to grow jobs in Minnesota—from contractors
architects, engineers, researchers,
Homes are no longer simple and installers to manufacturers and retailers.
and builders to create durable
homes that operate safely, When many of our homes were built, there What should be done first?
comfortably, and efficiently is was little concern about energy conserva- Many people assume that there is little they
known as building science. tion and efficiency, therefore little attention can do to significantly reduce their ener-
was given to things like insulation and air gy use and increase the efficiency of their
leakage. Energy was cheap and construction homes. In reality, there are many things that
materials and techniques were sufficient for typical residents can do themselves and
the time. many other things they can hire others to do.
Over the past several decades our homes Before you start on any large project, you
(and the things within them) have become should know what options you have and
increasingly complex. Rising energy costs, what the benefits may be. Today’s homes
along with environmental and other con- and their systems are much different than
cerns, have increased awareness and driven what was common 20, 30, or 50 years ago.
research into the operations of buildings. The interactions between the various com-
The effects of the interactions of structural ponents of a house are more complicated,
systems, weatherization components, me- and the effects of systems not performing
chanical equipment, and electrical devices properly or being out of balance can be
in today’s homes are the subject of an entire costly and sometimes dangerous. The Divi-
field of study: building science. sion of Energy Resources in the Minnesota
Saving energy benefits everyone Department of Commerce strongly recom-
mends having a home energy assessment
Depending on your home, you may see
(sometimes called a home energy audit)
substantial reductions in your energy use
before embarking on your energy improve-SAVING ENERGY MAKES GOOD SENSE 3
ments or remodeling. This assessment of Replacing equipment such as
how your house is functioning can help a furnace, boiler, water heat-
you decide what needs fixing, what needs er, ventilator, or air condi-
upgrading, and what needs replacement. tioner. Finding and address-
Many people have a follow-up inspection ing air leakage, insulation,
after work has been done to verify the esti- and other issues can help to
mated energy savings. correctly size new appliances
and ensure they will work as
Energy assessment: how your house works efficiently as possible.
A home energy assessor will evaluate the
Replacing windows, doors,
operation of your home by inspecting and
or siding. Properly installed,
measuring the performance of the building.
these improvements can
At minimum several things should
make your house much tighter,
be included:
which can change the fresh air re-
• A review of energy bills to identify basic quirements for some combustion appli-
usage and identify opportunities for ances or for the occupants. Blower Door
savings. Energy assessment tests include
Investing in major remodeling or additions.
• A blower door test to determine air Knowing the current operation of the home a blower door test (above) to
leakage rates. can help determine choices about designs, determine air leakage rates.
methods, or equipment options. In addi- Knowing how much and how
• Infrared camera scans of walls, attic, and
foundation to assess insulation levels and tion, pre- and post-construction testing quickly air is leaking through
locate possible air leak sources. can be used to verify energy performance your home’s envelope can
improvements. help prioritize energy-saving
• Efficiency and safety testing for combus-
strategies.
tion appliances (like furnaces, boilers, gas Problem-solving systemic or complex con-
fireplaces, and water heaters) to ensure cerns, such as excess moisture (including
they are operating properly and not con- condensation, mold, mildew, or leakage),
tributing to indoor air concerns. uneven heating or cooling, drafts, ice dams,
or high energy bills.
• A visual inspection for attic, wall, crawl-
space, foundation, basement, window, Buying or selling a home. Many people
door, and roof problems. already include a requirement for a home
inspection as part of a purchase agreement.
Although many inspectors include some of
Although this may identify structural
these tests as part of a general home inspec-
issues, mechanical system problems, code
tion, it is important to have all of the above
violations, and other health and safety
tests completed by a trained and qualified
issues, the typical home inspection may
energy assessor in order to determine the
not provide a complete look at the energy
best approach to improving the energy
usage for a home. An energy assessment
performance of a home.
will highlight energy-saving improvements
When should you get an energy that can reduce utility costs and improve
assessment? the health and comfort of future occupants.
Most homes—even recently built ones—can
How much does an energy
benefit from an analysis of the operation assessment cost?
and interactions of the various systems and
Home energy assessments that meet the
equipment. There are times when having
suggested minimum requirements cost
a professional diagnosis can solve compli-
from $100 to several hundred dollars, de-
cated problems while saving time, energy,
pending on the level of detail and the types
and money. Consider an energy assessment
of tests provided.
before:4 SAVING ENERGY MAKES GOOD SENSE
Contact your gas or electric utility to arrange for an ener- How do I pay for it?
gy assessment that includes the full range of testing. More Although many energy-efficiency projects (caulking win-
comprehensive assessments (for new construction or major dows, weather-stripping exterior doors, or insulating water
remodeling) are available from private contractors specializ- pipes) will cost just a few dollars, others (insulating exterior
ing in comprehensive home performance reviews. walls, air-sealing an attic, replacing a furnace, or adding
storm windows) may cost considerably more.
Many utility companies offer incentives on larger projects
(furnace replacement, attic insulation, new refrigerator) by
giving you a discount on energy bills or sending you a rebate
check when the work is completed. Other utilities offer free
or discounted services or products (like low-flow shower
heads, CFL bulbs, or energy assessments). Contact your local
energy utility or visit the Database of State Incentives for
Renewables & Efficiency (dsireusa.org) for details.
Community nonprofits and neighborhood organizations
The payback from this investment will be apparent for many offer a variety of services and programs, including energy
years in terms of increased comfort and safety and reduced assessments, energy education, free or discounted products,
energy use and the associated environmental costs. and financing. Contact your city or municipality to learn
what is available in your area.
How hard is it to make energy improvements? Your bank may be able to help, too. Ask about a low-interest
If you have some basic tools and are comfortable with mak- loan designed specifically to cover the cost of your ener-
ing repairs and improvements to your house, you can handle gy-saving projects, or consider a home-improvement loan
some of the projects suggested in this booklet and make the to fund them. Some banks offer energy-efficiency mortgag-
most of your energy-improvement budget. Be sure to check es, which take into account the reduced energy bills when
with your local municipality for permits and inspections. improvements are made to homes. The Minnesota Housing
However, don’t hesitate to call a professional for help if Finance Agency (mnhousing.gov) also offers a Fix Up Fund
you’d rather not do the work yourself; even with paying to Loan for home improvements—even if you do the work
have someone else do the work, the dollars gained through yourself.
energy savings in upcoming years will be worth the expense.
Be sure to check out the “Resources” section at the end of
this guide to get tips on hiring contractors.
Infrared Scans
Energy assessment tests can include scans from infrared cameras (at right)
to pinpoint voids in insulation, air leaks, and moisture problems. Locating
the leaks makes it easier to seal and make necessary repairs—and
improves the returns on other energy investments you make.SAVING ENERGY MAKES GOOD SENSE 5
Some Minnesota residents may be eligible for aid from the • If the qualified product costs more than a conventional,
state Weatherization Assistance Program or Energy Assis- less-efficient counterpart, purchasers will recover their
tance Program. Applications can be made through local investment in increased energy efficiency through utility
service providers; go to mn.gov/commerce for eligibility bill savings, within a reasonable period of time.
requirements, application forms, and contact information. • Product energy consumption and performance can be
Finally, for the latest information on tax incentives, rebates, measured and verified with testing.
or grant programs from federal, state, or local governments, When shopping for lighting, electronics, and appliances (in-
check out their websites. It is important to find out the cluding heating, cooling, and water heating), always look for
specifics (qualifying products, installation requirements, the ENERGY STAR® label. To find qualifying products or to
site analysis, inspections, etc.) before purchasing products or compare performance of several products that are ENERGY
services. Some programs require approved applications or STAR® labeled, go to energystar.gov.
specific products or procedures in order to qualify for the
funding. Not meeting the requirements may jeopardize
your incentive, rebate, or grant. A listing of many current
programs and links is also available at our website:
mn.gov/commerce.
ENERGY STAR®
ENERGY STAR® is a joint program of the U.S. Environmental
Protection Agency and the U.S. Department of Energy that
helps save money and protect the environment through
energy-efficient products and practices. Many appliances,
lighting products, and electronics can earn the ENERGY
STAR® label by meeting these energy-efficiency require-
ments:
• Qualified products must deliver the features and
performance demanded by consumers, in addition to
increased energy efficiency.6 AIR-SEALING
Simply speaking, the materials of a house that separate the outside from the inside are considered the
home’s envelope. It is the barrier that keeps us from experiencing the extremes of the outside environment
and keeps the inside of our home comfortable, dry, and energy efficient.
The home’s envelope includes windows, doors, walls, ceil- through cracks at the top of the house, it pulls cold air into
ings, and foundations. Each of these components consist of the lower areas.
several elements that go together to create the structure. So, • Negative air pressure infiltration starts when appliances
for instance, a wall section may consist of the interior paint, use air for combustion or when ventilation fans are oper-
the drywall, the framing lumber, the air barrier and vapor ated. Outdoor air enters through any available openings to
sealing, the insulation, the exterior sheathing, the siding, and equalize the pressure inside a home. This can be a problem
the exterior paint. Well-designed components work together if adequate fresh air for combustion appliances has not
to make the envelope as tight as possible. been provided. It can lead to a potentially dangerous car-
Home tightening bon monoxide risk as fresh air is pulled down chimneys or
vents, interfering with their proper operation.
Every home needs a certain amount of fresh air for the fur-
nace and appliances that burn fuel, for getting rid of excess Typically, air infiltration causes drafts and a chilly feeling
moisture, and for reducing odors and stuffiness. When this near windows and doors and in basements. Adjusting your
air exchange is controlled, it’s called ventilation. When it thermostat will not stop the drafts, but sealing hidden cracks
seeps uncontrolled through cracks and holes in the envelope and openings will. By stopping air leaks at their source,
of our home, it is called air infiltration. Air that leaks through you’ll stay warmer in the winter and cooler in the summer,
the ceiling, walls, foundation, and other areas are significant use less fuel, and reduce your utility bills.
sources of heating and cooling losses in a home—up to one
Where do you start?
third in some houses. Stopping air leaks is the best way to
Fortunately, air infiltration is one of the easiest forms of ener-
conserve energy, save money, and increase comfort. The
gy loss to correct. The process requires only a careful inspec-
bottom line: If you don’t tighten up your home first, other
tion of your home and some inexpensive weather-stripping,
improvements (like windows, insulation, furnaces) may not
caulking, and filler materials.
be as effective.
Most people know they should caulk and weather-strip
Infiltration through air leaks can occur in three ways: around the exterior of their homes to protect it from the
• Wind-driven infiltration happens during cold-weather elements. However, it is equally important to protect your
months when the wind blows cold, dry air into a house home from interior air leaks. Moist interior air can enter the
through cracks and openings and forces warm air out. walls and ceiling through cracks and holes, and condensation
During warmer weather, the wind blows in warm, humid buildup in those locations can damage or destroy insulation,
air, forcing cooler air out. wiring, wood, or other building materials.
• Stack-effect infiltration takes place during the natural
process of convection. As warm air rises and escapes
AIRTIGHT, SEALED RECESSED Ceiling fixtures require proper air-sealing
LIGHT FIXTURE
Light fixtures below an unheated attic must be tightly sealed to prevent air from leaking into
the attic space. Attic air leaks not only waste energy, they are the primary cause of ice dams.
Methods of sealing include:
• Recessed fixtures. New or retrofit recessed fixtures (including new LED fixtures) should
have airtight cans and gasket seals. Existing recessed lights can have special airtight boxes
sealed over them from the attic side.
• Flush-mount fixtures. Electrical boxes should be sealed with spray foam around any
cracks or openings into the attic.
Caution: Disconnect power to circuit until foam cures!AIR-SEALING 7
Look for air leaks Recessed lights and bathroom fans
Before research and building science demonstrated the role These fixtures can poke into the attic insulation and create
air leaks play in energy loss, most people assumed that a pathway for air leaks. Caulk around them from below
insulation was enough to stop heat flow through a build- with flexible, high-temperature caulk. Install an airtight
ing. Although insulation slows heat transfer, it is easily box sealed over the top of them in the attic, not only to stop
compromised by air flow, whether driven by outside wind air leakage but to reduce fire hazard from insulation lying
conditions or convection currents within the building. The against the fixture. When replacing light fixtures, use only
only way to stop this air movement—and the associated heat air tight fixtures.
loss—is by eliminating the holes and pathways between the
Chase for plumbing vent stacks
inside of the house and the outside.
This channel may run inside the walls of your home, from
The first step to tightening up your home’s envelope is
the basement to the attic, with openings at each floor where
performing a detailed inspection for air leaks, including a
the lines branch off. If the chase isn’t much larger than the
blower door and an infrared camera scan. This should be
vent where it enters the attic, seal with expanding foam. For
part of every energy assessment, and the inspector should be
larger chases, use drywall, wood, or rigid foam—and caulk
able to show you locations where air is leaking and needs to
or foam around all edges.
be sealed. A good rule of thumb is to start by plugging holes
and leaks in the attic; then move to the exterior walls, and Fireplace chimney and furnace/water heater flues
look for smaller leaks around doors, windows, and electrical Close the gap between house framing and the chimney and
switches and outlets; finally check out your basement. vent flues with metal; seal with red fire-stop caulk.
Attic air leaks: more common than you’d guess Knee-wall storage drawers
Most existing homes have many unsealed penetrations into If storage drawers are recessed into the attic space, build an
the attic for wires, chimneys, vents, etc. Sealing will prevent airtight, insulated box around the backside of the drawers.
heat loss and damage to building materials. Don’t forget to seal all joints with caulk or sheathing tape.
Hatches and doors to the attic Other holes
Weather-strip the edges of the access hole and insulate the Using the appropriate materials, seal all other holes between
back of the attic hatch/door. Don’t forget doors to unheated the heated space in your house and the attic.
knee wall areas.
Holes in attic floor
Seal all openings around electrical wires, pipes, ducts, and
vents with a good general-purpose caulk or spray foam. You
may need to use a filler material for larger holes.
CAULK OR SPRAY
Seal wires and conduit
FOAM
Electrical wires and conduit often enter attics through the tops of walls. Fill the hole around
them with spray foam or caulking.
CAUTION: If your wiring consists of old “knob and tube” style wires, or wires that are worn or
broken, they must be protected or replaced prior to insulating and sealing!8 AIR-SEALING
Attic air leaks = ice dams What NOT to do:
Although many years ago thought of as a problem with • I nstalling heating cables will shorten the life of your roof
roofing or attic ventilation, ice dams are actually caused by and cost you money to operate.
the presence of warm, moist air in the attic, combined with • R
emoving the ice with chippers, chemicals, or heat can
snow on the roof and the right weather conditions. Ice dams damage shingles, gutters, and other building components.
occur when heat gets into the attic and melts the underside
of the snow on the roof. The melted snow then flows down • A
dding roof vents—including powered vents—will not
the roof surface until it reaches a cold spot (such as the eaves eliminate ice dams, and often make the problems worse.
or soffit) where it forms a frozen dam, behind which more • A
lthough additional insulation—especially higher density
snowmelt and ice pile up. The ice buildup can back up under foam on the top plate of exterior walls—can reduce heat
the shingles, damaging them and allowing water to leak to transfer to the roof deck, insulation alone is insufficient.
the ceilings and walls below.
Air leaks can damage insulation and more
Water vapor carried with the escaping warm air may
condense, freeze, and build up in the insulation. When this
water builds up, it can soak the insulation (wet insulation
has little insulating value), cause plaster and paint to crack
Ice dams and peel, and lead to rot and other structural damage.
The primary cause of ice dams is attic air leaks.
Warm, moist air leaking through holes around plumbing vents, electrical wires,
chimneys, etc. leads to reduced performance of the insulation (right).
RISING WARM AIR
Foam spray (below) or caulking can seal up the air leak, saving energy HEATS ROOF
and preventing nearly all ice dams. PLUMBING VENT
SNOW MELTS
MELTED SNOW
WARM MOIST
AIRFLOW
ICE DAM
FOAM SPRAY GUN UNHEATED SOFFIT WARM MOIST
WARM MOIST AIRFLOW
AIRFLOW PLUMBING VENT
PLUMBING
UNSEALED VENT
AIR LEAK
INSULATION
INSULATION
CEILING PLASTER/DRYWALL
CEILING PLASTER/DRYWALLAIR-SEALING 9
Basement air leaks: easy to seal wiring in the basement ceiling. You may need to use filler
Most basements have multiple air leakage locations. Because material for larger holes.
of the physics of the stack-effect (causing warm air to rise), Basement windows
basements are a common source of cooler air leaking in
Using a masonry caulk or spray foam, fill cracks where the
through cracks or penetrations in the foundation or unsealed
frames of the windows are set into the walls. Windows that
joints where floor framing rests on the foundation wall. Air
are not used for ventilation or as fire exits can be caulked
then rises through holes around chimneys, vents, wires, and
shut permanently.
plumbing into the rest of the house. Careful sealing will help
to limit warm air entering the attic. Ducts
In homes with air ducts, there may be gaps where ducts pass
Sill plate and band or rim joist
through ceilings, floors, and walls. Caulk or foam where the
Caulk cracks between the sill plate and foundation wall
metal duct and the ceiling, floor, or wall meet.
using a masonry caulk, and fill cracks between the sill plate
and band or rim joist. Then insulate the band/rim joist area Other holes
by spraying with expandable foam or by cutting foam board Seal cracks or holes in the foundation with caulk, foam, or
insulation to fit and then caulking in place. Do not use fiber- the appropriate patching material. Don’t forget to check
glass, as it does not stop air infiltration and because moisture where the electrical, gas, water supply, telephone, and cable
from the basement can get between the fiberglass and the rim lines enter the house, and seal on the inside and outside.
joist, leading to mold and mildew.
DON’T SEAL COMBUSTION AIR SUPPLIES!
Chase for plumbing vent stack(s) Water heaters or furnaces may have a flexible duct that sup-
Sealing the chase at the basement end, as well as the attic, plies fresh air for combustion. These must be kept open! A “J”
will reduce the flow of air to the other floors in the house. loop near the duct end can reduce cold air in the basement.
Chimney for furnace and water heater Interior sealing: plug the holes around you
As in the attic, close the gap between framing and chimneys Air leaks in the occupied part of your home are the ones you
with metal; seal the edges with red fire-stop caulk. Vents are most likely to notice. The drafts of air infiltration can be
made of PVC (plastic) piping can be sealed directly with felt around windows, doors, outlets, and fireplaces. The re-
spray foam or regular caulking. sults of these air leaks can frequently be seen as condensation
or frost buildups on windowsills or the bottoms of doors.
Hatch or door to crawl space
Weather-strip the edges and insulate the back of the Window and door frames, trim, and baseboards
hatch or door. • C
arefully remove trim and caulk or foam the gap between
the wall framing and the window or door jamb (no fiber-
Openings through basement ceiling
glass, it doesn’t air-seal). If you are unsure how to proper-
Seal with caulk or foam the hole where the bathtub drain
ly remove and replace the trim, consider hiring someone
comes down and other holes for plumbing or electrical
qualified to do it.
Seal pipes, vents and ducts
There are many places that air can leak into a basement (left). Gas, electric or water
lines and vents for dryers, exhaust fans, or high-efficiency water heaters or furnac-
es that exit through foundation walls or rim joists should be caulked or foamed to
prevent air leakage (center). Furnace ducts that rise from basements through floors or
walls should be sealed where the metal meets the wood framing (above).10 AIR-SEALING
FLEXIBLE PATCH PLASTER OR
HIGH-TEMP CAULK NEW DRYWALL
• I f you don’t want to remove Exterior sealing: stop moisture
the trim, you can caulk the damage, too
edges of trim and baseboard Sealing on the outside of your home not
where it joins walls and only prevents air from entering, it can
WEATHER-STRIP floors with an interior-grade
CAULK
also prevent damage to siding, walls,
CAULK caulk. Use a clear caulk for insulation, windows, and doors due to
hardwood or tile floors and moisture intrusion.
trim with natural wood fin-
ishes and paintable caulk for Holes for pipes, wires, etc.
painted trim and carpeted Caulk or foam around openings for
floors. Note: caulk on wall/ electric, gas, oil, and water-supply lines;
trim may be a challenge drainage pipes; plumbing for outside
when repainting. spigots; cable TV and telephone cables;
mail slots/doors.
FOAM GASKETS
Missing plaster, cracks
Exposed laths indicate a direct Vents
Seal holes,
cracks, leaks
hole into wall and ceiling Caulk or foam around dryer vents,
cavities. Repair with plaster or cover with heating and cooling system vents, and
Anything that penetrates your walls or
new drywall. Repair smaller cracks using fresh-air supply vents for fuel-burning
ceilings is a potential location for an patching material, and repaint. furnaces and water heaters.
air leak. Gaps around windows, doors,
fireplaces, electrical boxes—even cracks Windows and doors Windows
in plaster—can allow air to move between Check the weather-stripping on all win- Caulk around window frames. If you
the inside and outside of your house. Seal dows and doors, and repair or replace have combination storm windows, caulk
them up with caulk, weather-stripping, or as necessary. Check the threshold on where the metal storm window frame
plaster. And foam gaskets on outlets and doors, and replace if worn or leaking air. meets the window’s frame; don’t seal
switches can increase comfort, avoiding Replace broken glass and reglaze or putty the moisture weep holes at the bottom
unnecessary energy use. loose windowpanes. Caulk around mov- of the frame. If you have wooden storm
ing parts of windows with nonpermanent windows that must be exchanged for
Seal the outside caulk that can be removed easily. You screens in the spring, use non-permanent,
There are many places to apply caulking can also install inexpensive window films non-staining rope caulk to seal the joint
or foam to weather seal the exterior of (inside only) to cut air leaks. between the storm window and
your home: the frame.
Electrical switches and outlets
• doors and windows; Install foam gaskets and child-safety Doors
• v ents for furnaces, dryers, water plugs on all switches and outlets—even Caulk around door frames. Install storm
heaters, air exchangers; on interior walls. Although this may doors if needed and check latches and
have a very small effect on heat seals.
• e ntry points for wires,
loss from air infiltration, it can
pipes, cables, have a noticeable effect on com-
Fireplaces:
faucets. fort, by reducing drafts. Waste more heat than they make?
A charming old wood-burning fireplace
Other holes in exterior walls
may seem warm and cheery, but it likely
Caulk or foam around all
loses more heat from your home than it
ceiling fixtures, heat registers,
gives off. Warm air in a home is sucked
medicine cabinets, bathtubs,
up the chimney and is replaced by cold
kitchen cabinets, drains, and
air leaking into the house. Especially as
water pipes where they
the fire dies down, more heat is drawn up
enter the wall in the kitchen
the chimney than is created by the fire—
and bath. Also seal any oth-
and the reduced rate of airflow can lead
er holes in exterior walls.
to backdrafting of dangerous flue gasses
and smoke into the living space.AIR-SEALING 11
Follow these tips to improve the opera- fore caulking or use a spray foam sealant
tion and safety of your fireplace and to instead.
reduce your energy losses: Older wood windows may have glass
• Improve the seal of the flue damper. panes that are held in place with putty
To test the damper’s seal, close the and glazing points. If the putty is cracked
flue, light a small piece of paper, and or missing, it is a likely air leakage
watch the smoke. If the smoke goes location and must be re-puttied. (Broken
quickly up the flue, there’s an air leak. panes should be replaced.) Although
Seal around the damper assembly with caulking may be used to repair/replace
refractory cement, but don’t seal the window putty, it may be difficult to
damper closed. apply neatly and may make future
• Install tight-fitting glass doors or an repairs a challenge.
airtight fireplace insert unit. Con- When shopping for caulk, you may be
trolling the airflow in your fireplace overwhelmed by the choices, so be sure
improves combustion efficiency by to read the labels and choose the caulk Seal fireplaces
10 to 20% and reduces air leaks up that will work best with the materials There are several ways to improve
the chimney. When there is no fire you’re sealing. The two basic types are the energy efficiency of a fireplace,
or embers, close all vents and dampers latex and silicone, and each have advan- including:
tightly. tages, depending on the circumstances.
• Seal flue damper.
• I f you infrequently use the fireplace, Most caulk is sold in tubes that fit a
• I nstall airtight doors (with
install an inflatable “chimney balloon” caulking gun; some are available in
in the flue of the chimney to reduce plastic squeeze-tubes. In addition, some good gaskets).
heat loss. These are available in several caulks come in aerosol cans; they’re a • I nstall a “chimney balloon” in
sizes and, if properly installed, can sig- good choice for filling gaps up to ½ inch. seldom used fireplaces.
nificantly reduce heat loss through the Note that some caulks are for indoor use
• I nsure proper operation/sealing
flue. Most have a quick-release handle, only, and that some are paintable—while
of fresh air supply.
and many have a safety feature that others are not.
will instantly deflate the balloon •C
aulk/foam where brick/stone
The benefit of high quality caulk will be
if a fire is started without removing meet wall or ceiling.
a longer-lasting seal; inexpensive caulks
the balloon. may last only a few years.
• M
any fireplaces and stoves have a
Before caulking, note the following
source of fresh air to aid in combus-
points:
tion—in fact it is required for most new
installations. Fresh air supplies should • Remove old caulk and loose mate-
have a well-sealed damper to prevent rials completely.
air leakage when not in use. • Make sure all surfaces are dry and
• T
he joint where a brick or stone chim- free of dirt, grease, or oil; wipe
ney meets the wall or ceiling can be a with rubbing alcohol to clean.
source of air leakage. Foam or caulk to • Do not apply when below 50
prevent unwanted airflow. degrees F or when rain is possible
before curing is complete.
Caulking is easy and cost-effective
• Tape the edges of the crack to keep
Use caulk to permanently seal air leaks
caulking off adjoining surfaces.
in spots such as the cracks and gaps
between exterior window and door Follow these tips to get a neat, uni-
frames and your home’s siding. Generally form bead of caulking:
speaking, you can seal openings up to ¼ • Cut the nozzle at a 45 degree angle at
inch with caulk alone. For larger gaps, the point where the diameter is equal
you’ll need to add a backing material be-12 AIR-SEALING
to the size of bead you need—near • Low-expansion spray foam should
the end for a small bead, farther up also be used to seal the space be-
for a wider one. tween framing and jambs in win-
• While applying constant pressure on dows and doors; standard expanding
the trigger, hold the gun at a 45 de- foam can cause jambs to warp and
gree angle and move it slowly along affect operation of the window or
the joint you are sealing. door.
• Make sure you have enough caulk in • When you’re working in a large area
the joint to seal both edges and allow such as your attic, it may be inconve-
for any shrinkage. nient to carry and keep track of sev-
eral cans of expanding foam. Instead,
• Smooth the caulk with a plastic tool. consider renting a contractor’s foam
Once you have applied the caulk, it gun, which has a long nozzle and
takes time for it to dry, or cure. Cur- can help you get into tough-to-reach
ing time is described two ways. The spaces.
tack-free time tells you how quickly the
fresh caulk’s outer surface will dry—or
Try these materials for special jobs
skin over. The total cure time indi- In addition to the types of caulk and
cates the time required for the caulk to spray foam sealant described above,
become completely stable—or reach you may need to use fillers to plug
the point where no further drying or extra-wide gaps. Fillers come in a wide
shrinking will occur. variety of materials—cotton, fiberglass,
foam, and sponge rubber—and you can
Most caulks pose no known health
find them in the caulking department
hazards after they’re fully cured. How-
of your local hardware store or home
ever, some high-performance caulk-
center. However, these fillers are not
ing compounds contain irritating or
designed for exposure to the elements;
potentially toxic ingredients, and you
you’ll need to caulk or seal over them.
should apply them only when there is
adequate ventilation; carefully read the • T
o close gaps too wide for foam, cut
manufacturer’s instructions and take sections of rigid foam insulation to fit
the appropriate precautions. In addi- and glue into place with expanding
tion, make sure pets and people do not foam—before covering with wood
come into contact with fresh caulk. or another appropriate building
Steps to caulking material.
Laying a consistent bead of caulking can Use spray foam for large gaps
• F
or winter, use rope caulk to seal
take some practice. Follow these steps to • Expanding foam is ideal for fill- windows and other spots that you’ll
provide a good seal: ing larger cracks that caulks can’t want to be able to open during the
handle. It comes in aerosol cans and spring. Rope caulk is a gray, put-
• I nsert tube into gun.
takes a short time to cure. The foam ty-like material that comes in long
•C
ut tip at 45 degree angle at desired is very sticky and attaches itself strips or rolls. It’s easy to install and
thickness; use wire/nail to break seal quickly to whatever it touches, so be remains flexible, and you can just
at base of spout. prepared to pick up any messes fast. pull it off when the weather turns
•S
queeze trigger while moving tip • You also can use foam instead warm. Note that rope caulk will not
steadily along joint to be filled. of caulk for sealing in your attic; last longer than a year, and oil-based
•S
mooth bead with tool or gloved low-expansion foam will stick better rope caulk may stain painted areas.
finger, making sure both edges to dusty and dirty surfaces than
are covered. caulk.AIR-SEALING 13
Keep heated and cooled air in ducts
The ducts for a forced-air heating and
air-conditioning system can be one of
your home’s biggest energy wasters,
especially if those ducts run through
unheated or uncooled spaces (like attics
or crawl spaces).
Properly sealed ducts can deliver heated/
cooled air where you need it, instead of
leaking out where you don’t. This allows
your furnace/air conditioner to work less
METAL/FOIL TAPE MASTIC
to make you comfortable.
ADHESIVE
• Check the ducts for air leaks, including
around the filter cover. Repair leaking
joints first with sheet-metal screws;
then seal joints with either latex-based
mastic with embedded fiberglass mesh
or metal/foil tape (UL 181). Don’t use
plastic or cloth duct tape because it will
harden, crack, and lose its adhesion.
• Wrap ducts in attics/crawl spaces with
special duct insulation. Seal all insula- FILTER COVER
tion joints with the appropriate tape.
• Make sure ducts fit tightly to the regis-
ter openings in floors and walls; if they
don’t, seal them with caulk.
• Seal return ducts, too, so you won’t be
breathing basement or crawl space air.
• Make sure registers and baffles are
adjusted properly to distribute heated
and cooled air to where you need it.
For example, in the winter close regis- SEAL WITH CAULK, MASTIC,
ters in unused rooms. OR METAL/FOIL TAPE
• Don’t confuse duct-sealing with
duct-cleaning! There are no energy-
related benefits to duct-cleaning.14 INSULATION: A BLANKET FOR YOUR HOUSE
AIR CHANNEL Insulation slows the heat flow through a building’s envelope. It
ROOF
SHEATHING
works year-round to make your home more comfortable and energy
RAFTER
efficient. In the winter it slows heat loss and in the summer reduces
heat gain and helps keep your home cool.
BAFFLE
Adding insulation to your home can percent or more. (Dense-pack cellu-
cut heating and cooling costs 15% lose for use in wall or floor cavities,
BLOWN-IN or more, depending on factors such however, has negligible settling.)
CELLULOSE
as the amount of existing insulation Be sure to check the manufacturer’s
CEILING
JOIST in your home, house size, air leaks, specifications before you buy insu-
INSULATION BATT
personal energy use, and living hab- lation, and follow supplied charts to
Attic insulation options
its. Many variables affect the exact ensure adequate long-term coverage.
There are several good options for installing addi- amount you’ll save, but insulating Finally, some types of insulation—
tional insulation to an attic. Unless wet from roof your home is usually a wise energy such as dense-pack cellulose, poly-
leaks or excess moisture from the building below, investment. urethane, and polyisocyanurate—
there is no need to remove existing insulation. Your
While every house is different, the combine both an air-sealing barrier
choices include:
basic rule of insulating is the same and insulation in one step. Some
Batts or blankets. Fiberglass is available in a va- for all homes: Install insulation on insulation products also serve as a va-
riety of thicknesses and widths, and can be laid on any surface separating a heated space por retarder when properly installed.
top of existing insulation. If the top of the existing from an unheated space. Even if your When comparing products, carefully
insulation is below the top of the ceiling joists, fill home already has some insulation consider the costs and benefits of do-
the spaces between the joists first. Then lay batts or in these areas, there can be great ing the entire job: insulation, air-seal-
blankets perpendicular to the joists to provide the benefits in adding more insulation, ing, and vapor retarder.
best coverage. Carefully cut around pipes and truss especially in your attic.
Start in the attic
pieces, and don’t bunch or fold the fiberglass. Recommendations vary for the
Your home can lose a significant
Blown-in. Generally composed of cellulose (made amount of insulation necessary in
amount of heat through the top, so
from recycled newspaper) or fiberglass fibers, particular locations for peak energy
the best place to start insulating is the
savings, depending on factors such
blown-in insulation does a much better job of filling attic. Compared to other parts of the
as climate conditions, the sections
around framing and providing a consistent layer house, access to the attic is relatively
of your home being insulated, and
of insulation. Blown-in insulation can be applied easy, therefore the cost of attic insu-
the kinds of materials used in your
directly over existing insulation. Proper application lation projects is considerably lower.
home’s construction.
requires a special machine and moderate skill. It is also the easiest place for “do-it-
Regardless of which insulation material is selected, Insulation is rated by R-values yourselfers” to begin. You can install
The R-value (or thermal resistance) of loose-fill, batt or blanket insulation
plastic baffles must be inserted between rafters
insulation is a measure of its ability over existing insulation. If you choose
extending past the wall plate to keep insulation
to resist heat loss or heat gain. The to use a blown-in insulation (such as
from falling into soffits and to provide ventilation.
higher the R-value, the better a mate- fiberglass or cellulose ) or a sprayed-
And every attic insulation project must also include
rial insulates. An insulation’s R-value on insulation (such as polyurethane
sealing of air leaks!
is based on its performance with no or polyicynene), you’ll probably need
BLOWN-IN
air movement, therefore the effective to have it professionally installed.
CELLULOSE OR
FIBERGLASS
FIBERGLASS BATT R-value of a particular insulation may Many home attics in Minnesota have
OR BLANKET be much lower than its rated R-value, some insulation; most can benefit by
especially if the insulation is not adding more attic insulation. Increas-
EXISTING
properly installed—or if air leaks ing attic insulation to an R-50 can
INSULATION are not sealed before the insulation provide a good barrier to heat loss.
is added. To determine the present R-value of
Blown or loose-fill insulation ma- your attic insulation, have an energy
terials will settle after installation, assessment; you can also measure the
reducing their effective R-value by 10 height of the insulation and multiply
JOISTSINSULATION: A BLANKET FOR YOUR HOUSE 15
TOP PLATE ROOF SHEATHING
times the R-value per inch of the material If the attic space has never been OF EXTERIOR
that is in place (2.5 to 4.0 per inch, on framed or finished, insulating WALL RAFTER
average). Roughly 12 to 20 inches and air-sealing can follow the BAFFLE
(depending on the material used) will standard practices as if it were CEILING
JOIST
provide an R-50 rating. Although it new construction. If, however,
generally won’t hurt to add more, the knee walls and ceilings are
return on the investment decreases as in place, special care must
the R-value increases above R-50. be taken to ensure a good
result. (Note that the same CEILING
Things to look for if you do it yourself BLOWN-IN
approaches to sealing and
If you are insulating your own attic, there CELLULOSE
insulating also apply to homes
are several things to check out to ensure that have an attic above a second floor— SPRAY FOAM INSULATION
the best possible results: a “two-story-and-a-half.”)
Insulate the top plate to
• Check for attic air leaks around pipes, reduce ice dams
Four surfaces must be sealed
wires, and chimneys and seal them up.
and insulated In most homes, the top of the exterior
• Make sure baffles are installed at eaves There are four parts to a typical story- wall (the “top plate”) is very close to
to allow ventilation and prevent “wind- and-a-half framing system (along with the the roof deck because of the slant of
wash” of insulation. vertical gable ends). Each part requires a the roof. This means there is much less
• Inspect wires and fixture and junction different approach for proper air-sealing space for insulation, especially when
boxes before covering with insulation. and insulation. baffles for ventilation are installed. Less
What about open ceilings or flat roofs? Ceiling insulation means more heat loss, and it
The flat ceiling is similar to an attic floor. is right at the location prone to ice dam
Insulating a cathedral ceiling, A-frame
Batts or blown-in insulation can be in- formation.
house or flat roof is an especially difficult
stalled between and over the ceiling joists. The solution is to apply an insulating
job, because there is little or no space
Access to the space may be through an at-
between the ceiling and roof. One option material with a higher R-value, such as a
tic door or through roof vents. If the knee
is professional installation of spray-in spray foam (above), to increase the effec-
wall space is unheated, baffles must be
insulation materials; alternatively, build- tiveness of the insulation at that critical
installed for ventilation. Air-sealing of all
ing out of roof rafters to allow additional location. There are challenges, however,
penetrations (access doors, wires, fixtures,
insulation is also possible. A third option in gaining access to the space. Here are
vents) must also be done.
is to have foam insulation applied beneath three options:
the roof deck during a re-roofing project. Slants
• A n insulating contractor can often
All options must also provide ventilation The slanted part of the wall should be
access hard-to-reach top plates from
to current code. treated like a cathedral ceiling. Building
inside the attic with the use of an
out the rafters to allow for additional insu-
Insulating the “story-and-a-half” lation and ventilation is the best solution. extended “wand” as part of their spray
Many homes built in the middle of the Professional installation of a spray foam is equipment.
20th century were single-story with a also possible, as well as rigid foam under •S
offit pieces can be removed and
large “expansion attic” above. These areas the roof decking. If the space behind the access gained from underneath and
frequently became finished living space— knee wall is to be kept as heated storage, outside of the attic.
and were often uninsulated or insulated the insulation needs to extend all the way
• I f a re-roofing is planned, roof boards
improperly. Because of the complexity to the floor along the slants.
or plywood can be removed to gain
of the framing and the difficulty gaining
Walls access from the top and outside of
access to some of the areas that need to be
The vertical walls (knee walls) can be the attic.
insulated, the story-and-a-half can present
insulated and sealed just like vertical walls
an insulation and air-sealing challenge.
on the lower part of the house, with the
But, considering that so much heat can es-
following exceptions:
cape through the top of a building, proper
air-sealing and insulating of these struc- • If the knee wall space is heated storage,
tures is essential. no knee wall insulation is required (see
slants, above).16 INSULATION: A BLANKET FOR YOUR HOUSE
• If the knee wall space is unheated storage, the knee wall Check the top of the basement foundation
should be insulated like any vertical wall. Gypsum (or The wooden rim (or band) joist area—where the house’s
foam boards for additional insulation) can be installed wooden structure rests on the concrete foundation—is the
over the studs on the knee wall side to protect the fiber- best place to begin. It’s the simplest and least expensive base-
glass. Air-sealing of all penetrations (access doors, outlets, ment area to insulate, and it will bring you the highest return
wires, vents) must also be done. If there are built-in draw- on your investment. And, because it is usually above ground,
ers or cabinets, a sealed and insulated box must be built there is little risk of moisture migration from the exterior.
around them on the knee wall (cold) side.
Insulate with cut-to-fit pieces of rigid, extruded polystyrene
Floor or polyisocyanurate foam, caulked or foamed into place, to
The space between the floor joists beneath the knee wall is avoid air leaks. Fiberglass is not recommended because it does
often neglected in terms of insulation and sealing—and is not provide an air-tight seal. Moisture from the basement
often the most difficult to access. If the knee wall space is can migrate through the fiberglass where it condenses on the
heated storage, no floor joist insulation is required. Other- cooler rim joist, leading to potential problems with mold or
wise, insulation must be installed beneath the floorboards wood rot.
from the outside junction with the roof to a point beyond the
knee wall. The methods include: Insulating the foundation walls
Concrete (whether block or poured) is extremely porous, and
• Removing floorboards to place batts between the joists.
unless sealed from the outside it is a likely source of moisture
A “plug” of gypsum or foam insulation board should
into a basement. Because migrating and condensing moisture
be installed beyond the knee wall, caulked or foamed to
can be trapped behind wall insulation—leading to mold and
prevent air leaks.
mildew growth—insulating basement walls is challenging.
• Drilling holes in the floorboards to install dense-packed Even historically dry basements can be subjected to water
cellulose insulation. Because dense-packed cellulose pro- migration or seepage during severe storms or flooding.
vides an air barrier, no additional air-sealing is required. (Don’t be misled by claims that products that are painted or
Head for the basement applied to interior basement surfaces will prevent moisture
from seeping through walls or floors—they can’t.)
Most Minnesota homes have basements with either concrete
block or poured-concrete walls. While these make sturdy Attaching wooden studs to the foundation wall and install-
foundations, they’re poor insulators and have a very low ing fiberglass insulation (a method used in previous years)
R-value. Therefore, an uninsulated basement can account is no longer recommended. The wood and insulation can
for a significant amount of a home’s energy loss. become a good medium for growing mold and mildew when
BAFFLE WITH
moisture finds its way between the foundation wall and the
AIR CHANNEL insulated wall.
CEILING
JOIST ROOF
SHEATHING
BLOWN-IN
CELLULOSE
INSULATION BATT
ROOF
RAFTER
KNEE WALL
GYPSUM OR RIGID FOAM
FLOOR PLUG CAULKED IN PLACE
JOIST
Knee wall insulation Rim joist insulation
Attention to detail is critical when insulating and sealing the knee wall area in an Install rigid foam pieces, carefully sealing edges and around pipes, wires,
expansion attic. Because heat rises, any insulation voids or unsealed cracks will and vents to prevent moisture from damaging wood framing. Alterna-
allow large amounts of air to escape, reducing thermal performance and increasing tively, the application of a spray foam (usually done by a contractor) can
energy costs. provide good insulation and air-sealing.INSULATION: A BLANKET FOR YOUR HOUSE 17
Interior basement walls—that have a very low risk of mois- air-sealing at these locations. A professional insulation con-
ture potential—can sometimes be insulated successfully tractor can often access these challenging locations:
with rigid foam panels; proper assessment and installation • C
antilevered floors over an exterior wall can be sealed
by a professional contractor is strongly suggested, however. and insulated with spray-in polyurethane, polyicynene,
Attention to details—such as proper sealing—can reduce or blown-in cellulose insulation through small holes on
the chances of damaging mold and mildew problems. It is either the interior or exterior. Air-sealing of joints and
important to note again, however, that foundation walls that cracks (with spray foam and other products) is critical
are not sealed from the outside will potentially allow mois- to prevent moisture from damaging insulation or
ture to migrate into the basement. building components.
Unfortunately, the recommended approach to basement • B
ay or bow windows can be insulated with rigid board
insulating can also be costly: removing the soil outside the insulation or spray-in foam at the “floor” and the “roof”
house all the way to the footing, sealing the foundation wall, of the projection.
providing for proper drainage, then insulating with rigid
foam on the exterior of the wall. An alternative approach • T
uck-under garages are particularly important to air-seal
uses a high pressure sprayer to remove soil from alongside and insulate. The risks of fumes (from vehicles or things
the foundation wall. The resulting narrow trench is filled stored in the garage) migrating into the house above can
with a specially formulated spray foam that provides insula- be significant. Sealing all joints and cracks with spray foam
tion as well as moisture control. A project of this magnitude and then applying rigid foam insulation covered with gyp-
requires hiring an experienced contractor. sum board is a good option.
• S
lab-on-grade homes that were not insulated properly
Insulate floors over unheated spaces during construction can sometimes have rigid insulation
Floors over a basement that have a heat source such as a board with plywood flooring
furnace, boiler, or wood stove don’t need to be insulated. installed over the slab.
However, floors over an unheated area such as a garage, a
porch, or open ground can be a source of considerable heat RIM JOIST
PROTECTIVE loss. Window projections (such
WALL COVERING as bay or bow windows) also FLASHING
PROTECTIVE WALL FOUNDATION
need to be insulated and COVERING WALL
RIM JOISTS
sealed where they protrude
MOISTURE
from the surrounding wall. PROOFING
EARTH Some homes (especially
older) may not have had RIGID
INSULATION
adequate insulation or
EXCAVATED
TRENCH
DRAIN
TILE
MOISTURE
Basement Insulation Options
SAND
PROOFING
Another exterior option
FOAM
INSULATION FOUNDATION An alternative to insulating
BOARD
GRAVEL and sealing all the way to the footing on the exterior founda-
tion wall is to do it part way (sometimes called the apron method). Dig a trench about
The best way: exterior two feet wide and about 18 inches deep and insulate the wall with a vertical piece of
Although usually more costly (in an existing building), the insulation of foun- rigid foam. Then place a horizontal piece of rigid foam slanted away from the wall at
dation walls from the outside is the best way to provide thermal efficiency the foot of the vertical piece. This approach will provide some insulation for the base-
and protection from moisture problems, mold, and mildew. Proper sealing ment wall and (if done properly) can aid in reducing the intrusion of water through the
and drainage are important in any exterior foundation insulation project. basement wall. Attention to detail regarding flashing, surface preparation, and joint
sealing will reduce the likelihood of basement water problems.
From the inside—usually not a good idea
Because of the risk of mold and other moisture problems, the insulation of interior basement walls is very challenging to do prop-
erly. Unless basements have a very low risk of moisture potential, it is better to leave the walls uninsulated on the interior to allow
drying and reduce mold and mildew issues.You can also read
