Weatherizing
you doors
and windows
will save
significantly
on your
Heating and
Cooling
bills.
Use the
steps below
to help save
energy and
lower your
bills.
Air
Leakage
Table
of Contents
Introduction
to Air
Leakage
Benefits of
Leak Sealing
Before You
Start
Leak Sealing
Materials
Sneaky Leak
Detection
Techniques
Leak Sealing
Techniques
Windows
Doors
Walls
Basements
Attics
Fireplaces
Checklists
for Leak
Sealing
Introduction
to Air
Leakage
In the
winter, cold
air seeps
into your
house,
replacing
the warm
heated air
which
escapes.
In the
summer, the
opposite
occurs. Air
leakage is
the result
of pressure
differences
between the
inside and
the outside
of your
house, and
can arise
from
temperature
differences,
wind,
appliance
use, and
living
habits.
Cold winter
air leaks
into the
home in the
basement and
first floor
levels when
the pressure
outside is
higher. This
is called
infiltration.
Cold air
infiltration
can often be
felt around
doors,
windows,
walls, and
foundations.
In the attic
and upper
floor
levels, warm
air leaks
out through
cracks in
attic doors
and walls,
and around
windows,
plumbing
vents, and
chimneys.
Enough air
escapes from
a typical
house every
day to fill
two Goodyear
blimps.
Benefits of
Leak Sealing
: Save
Energy and
Money
If you live
in an older
house that
has not been
fully
weatherized,
somewhere
between 20%
and 50% of
your heating
and cooling
bills can be
attributed
to air
leakage
alone. You
may be
needlessly
losing
hundreds of
dollars each
year as
heated or
cooled air
slithers
through the
cracks in
your home.
Sealing air
leaks is the
first step
in a program
to improve
the energy
efficiency
of your
home. The
energy,
time, and
money you
spend will
pay for
itself
quickly -
often in one
winter! A
thorough job
of leak
sealing can
cut your
home's total
air leakage
by 33-46% -
reducing
your heating
and cooling
bills up to
20%.
Once air
leakage is
controlled,
insulation
can reduce
your bills
by another
25-75%!
Improve
Comfort
Levels
Reducing air
leakage and
proper
insulation
help in the
winter to
stop
uncomfortable
drafts in
your home.
They also
make it
easier to
maintain
adequate
humidity
levels for
indoor air.
The amount
of cold dry
air which
enters and
warm moist
air that
leaves your
home is
reduced. In
summer you
can get the
opposite
advantage,
keeping dry,
cool air
indoors
where you
want it.
Maintain Air
Quality
Non-weatherized
older homes
leak 4-5
times more
air than is
necessary to
maintain
adequate air
quality.
Most of this
air leakage
occurs where
you need it
the least -
in your
basement and
attic. By
taking the
steps
described
below you
can greatly
reduce air
leakage in
an older
home, while
also
maintaining
air quality.
Caution : It
is advisable
to test your
basement for
radon,
especially
if you are
going to
seal it
thoroughly.
If you also
thoroughly
seal the
other living
areas of
your home,
you should
pay careful
attention to
managing air
quality.
When
effective
sealing
reduces
infiltration
and
exfiltration
nearly to
zero, toxic
fumes from
household
items - from
cleaners to
carpets -
can build up
to serious
levels.
Reduce
Moisture
Damage
Tremendous
quantities
of moisture
are
generated
inside the
home from
bathing,
cooking,
laundry,
plants, and
people.
Moisture
also enters
through
basements
and crawl
spaces. Warm
air can leak
into your
cold wall
cavities and
attic,
carrying
moisture
which can
then
condense. If
unchecked,
moisture may
contribute
to the
deterioration
of building
materials
and reduce
the
effectiveness
of your
insulation.
Before
You Start
A few
important
items should
be noted:
Exercise
caution when
performing
work on your
house -
follow all
necessary
code and
safety
procedures
outlined by
local
government
agencies and
product
labels.
All fuel and
dollar
savings are
estimates
based upon
currently
available
research.
Consider
adding a
combustion
air supply
vent to your
furnace or
boiler room.
Otherwise
the
combustion
exhaust
process will
tend to
increase
infiltration
into your
home and
reduce
heating
system
efficiency.
Tools and
safety
equipment
Leather
gloves
protect your
skin from
fiberglass
and
sealants.
Long sleeves
and pants
are
recommended
too. A face
mask filters
out
insulation
particles
when you're
working in
the attic.
Rags should
be used to
clean
surfaces for
proper
adhesion.
Use a wet
sponge (not
your mouth)
to moisten
your finger
before
finger-smoothing
the caulk
you apply. A
hacksaw and
screwdriver
are
necessary to
install
aluminum
door sweeps
and some
types of
weather
stripping. A
flashlight,
hard hat,
and broom
come in
handy during
attic and
basement
leak
sealing.
Boards, laid
crosswise
over ceiling
joists, may
be needed
when working
in
unfinished
attics.
Code and
Safety
Warning
These
instructions
do not
explain all
necessary
code and
safety
procedures.
Consult with
your local
building
permit
office for
code
specifications.
Leak
Sealing
Materials
Most leak
sealing
techniques
can be
completed in
a few hours
with just a
few tools
and a
variety of
common
materials
that can be
found at
most
hardware
stores,
lumber
yards, or
large
department
stores. Use
quality
materials to
insure
durable and
effective
leak seals.
Caulk is
used to fill
small cracks
and holes. A
caulk gun
dispenses
the caulk.
Pure
silicone
caulk is
necessary
around areas
subject to
high heat
(lights,
vents, or
chimneys).
Silicon
latex or
acrylic
caulk can be
used in
other areas.
Here's a
quick guide
to selecting
the right
caulk for
your caulk
jobs:
Acrylic
Latex - for
wood siding,
around doors
and windows.
Easy to
apply, cures
fast, paint
able, comes
in colors,
water
clean-up,
good for
interior
use, low
odor and
useable on
exterior.
Silicone -
for metal,
glass, tile,
smooth and
non-porous
surfaces.
Good
flexibility,
low
shrinkage,
can be
applied at
most
temperatures,
joins many
dissimilar
materials
and cures
fast.
Butyl Rubber
- for
concrete,
block and
brick,
gutters,
aluminum
siding,
flashing and
chimneys.
Can be used
in
high-moisture
areas and
below the
soil level.
Paint able
and comes in
colors. Can
be applied
in
below-freezing
temperatures.
Silicon
Acrylic -
for wood
siding,
masonry,
metal, glass
and tile.
Excellent
adhesion and
flexibility,
weather-resistant,
easy to
apply, water
clean-up,
paint able
and comes in
colors and
clear.
Foam sealant
can be used
to fill
larger holes
and gaps. It
is normally
sold in
pressurized
cans. Since
it sticks
well to most
surfaces -
including
your hands -
be sure to
use the
plastic
gloves
provided in
the box! Do
not use foam
sealants
that contain
CFCs. (CFCs
-
chlorofluorocarbons
- are a
major
contributor
to ozone
depletion.)
Around
windows and
door frames
be sure to
use
non-expanding
foam.
Tightly
rolled,
"un-faced"
(paperless)
fiber glass
insulation
can be used
to help
insulate
larger holes
and gaps
along the
basement
foundation
sill or
along attic
rafters, but
it is not a
good sealant
by itself.
If you plan
to use it in
these ways,
first caulk
the sill
seal or
outer
cracks, then
place the
fiber glass
insulation.
Finish up by
friction
fitting
extruded
polystyrene
into the
gaps.
Rope caulk
provides a
temporary
seal around
windows and
doors. It
can be
removed
easily in
the spring
and stored
in a plastic
bag for use
next year.
To fill
larger gaps,
use several
strands
twisted
together.
Weather
stripping,
such as
V-strip ,
works well
around the
movable
parts of
doors and
most older
windows.
Installation
for windows
requires
dismantling
the lower
sash.
Clear
plastic is
used to seal
and insulate
the inside
of windows.
It is
typically
attached
with a
double-sided
tape or a
vinyl
snap-in
track. For
best
adhesion,
apply these
only to
clean, dry,
oil-free
surfaces.
Door sweeps
, made of
either vinyl
or aluminum,
are a form
of weather
stripping
used to seal
the bottoms
of doors to
unheated
areas.
Sneaky
Leak
Detection
Techniques
Many air
leakage
spots can be
seen with
the naked
eye or felt
during harsh
weather
conditions
with your
hand. A
moistened
finger is
one of the
best tools
to detect
air movement
into the
house. A
burning
stick of
incense
serves
nicely to
detect air
leaving the
house.
To improve
your
effectiveness
in finding
air leakage
points, use
an exhaust
room fan or
attic fan to
depressurize
your house.
Outside air
will be
artificially
sucked into
the home -
making small
leaks easier
to detect.
First turn
off or turn
down the
thermostat
on any
appliances
which may
allow
harmful
combustion
by-products
into your
home (such
as your
furnace and
hot water
heater).
Then,
tightly shut
all your
doors and
windows. If
you have a
fireplace,
be sure to
clean out
any ashes
and close
the flue and
fireplace
doors before
turning on
the fan. If
you use a
window fan,
seal the gap
around the
fan with
rags or
plastic and
tape. To
test for
leaks, turn
your fan on
high speed.
The method
described
above is a
less
sophisticated
method of
performing a
"blower door
test". The
blower door
quickly
depressurizes
the house.
Air leaks
are then
efficiently
located
using
special
"smoke guns"
developed
for the
test.
Leak
Sealing
Techniques
Windows
For indoor
caulking, a
clear
acrylic or
silicon
latex caulk
are
recommended.
These are
durable and
easily
painted.
Seal the gap
between the
wall and the
window trim.
The surface
should be
clean and
dry. First
insert the
tube in the
caulk gun
and cut the
tip off the
tube with a
sharp knife.
Varying the
depth and
angle of the
cut will
affect the
size of the
caulk
"bead".
Pierce the
plastic seal
in the tube
by inserting
a long nail
or coat
hanger into
the tip
opening.
Apply the
caulk "bead"
in a
continuous
motion,
pushing the
bead into
the crack by
holding the
caulk gun at
a 45 angle
to the work
surface.
Release the
handle
before
reaching the
end of the
crack to
reduce bead
"run-on" and
reduce
waste.
Run a
sponge-moistened
finger over
the caulk to
provide a
smooth
surface.
Keep plenty
of rags on
hand to deal
with drips
and clean
up. Place
the nail you
used to
pierce the
tube back
into the
opening to
prevent the
caulk from
drying.
"V-strip"
weather
stripping is
used to seal
gaps around
the sides
and bottom
of older
windows.
First clean
the surface
where the
V-strip will
go. Then cut
two strips
2-3" longer
than the
bottom
window sash.
This will
allow you to
extend the
weather
stripping
above the
sash so the
window won't
catch on the
weather
strip edge
when opened
in the
spring. Also
apply
V-strip
under the
bottom
window sash.
For the
center of
the window
where the
sashes meet,
use rope
caulk. Close
and lock the
window to
make the
sash fit
tightly.
Apply the
rope caulk,
pushing it
into the
crack. Rope
caulk can be
used as a
temporary
alternative
to weather
stripping
and to seal
gaps around
storm
windows or
sliding
windows and
in other
areas where
weather
stripping is
not easily
applied. Do
not caulk
"weep" holes
in storm
windows.
These tiny
holes,
usually at
the bottom
of the
storm,
prevent
moisture
damage by
allowing
moisture to
escape.
Window
plastic is
added to
windows to
reduce air
leakage. It
also adds an
insulating
layer to
your window.
Two types of
window
plastic are
popular,
clear vinyl
with snap-in
track and
clear "heat
shrink" film
with
double-sided
tape. Vinyl
with snap-in
track is
reusable for
several
years. Heat
shrink
plastic is
less
expensive
but is not
easily
reused.
Make sure
your window
trim is
clean and
dry. First
attach a
continuous
strip of
tape or
track around
the inside
edge of the
trim. With
vinyl, start
at the top
of the
window,
snapping the
edge of the
vinyl into
the track
with the
"retainer
strips"
provided.
Wrinkles in
the vinyl
will
disappear
with time.
Heat-shrink
plastic is
sealed on
the window
edges with
double-sided
tape. It can
be
"heat-shrunk"
using a
blow-dryer
for a
wrinkle free
finish, but
don't over
shrink the
plastic or
you will
pull off the
tape.
Doors
Caulking and
weather
stripping
are also
performed on
the exterior
doors of a
home. The
technique is
similar to
that of
windows,
with the
exception of
the door
bottom. Here
a "door
sweep" is
used to seal
against the
door
threshold.
Measure the
bottom of
the door to
determine
the length
of the
sweep. Cut
equal
amounts off
each end of
the sweep,
using a
hacksaw for
metal sweeps
or scissors
for vinyl
sweeps. Make
sure that
the door
sweep
overlaps the
threshold
without
interfering
with the
operation of
the door.
Attach the
sweep to the
bottom of
the door
with the
screws
provided.
With vinyl
sweeps,
remove the
protective
plastic from
the
self-adhesive
backing and
stick the
sweep to the
door.
Walls
Foam gaskets
are used to
seal
switches and
outlets
which are
not
paint-sealed
to the wall.
Use a
screwdriver
to remove
the screws
holding the
cover to the
wall. Put
the
screwdriver
down while
you install
the gaskets.
Air leaks
through
interior
walls,
flowing up
into the
attic, as
well as
through
exterior
walls. So
install the
gaskets on
all your
walls.
Plastic
safety plugs
are
available to
stop air
leaks
through
unused
electrical
outlets.
Caulk can
seal the
smaller
cracks in
walls.
Places to
caulk
include
areas where
electrical,
phone, TV
antenna, and
plumbing
penetrations
occur.
Another
common area
is the
baseboard
where trim,
drywall, and
the flooring
come
together.
Use a clear
or paint
able caulk
if you're
sealing
within the
living area.
Pressurized
expanding
foam is
useful in
filling
large
cracks.
Proper skin
protection
is
important.
Most
products
have plastic
gloves
included in
the box.
Shake the
can
thoroughly.
Hold the can
upside down
and squeeze
the trigger.
Allow for
expansion by
filling the
crack only
40% full.
The unused
foam doesn't
store well,
so it is
best to use
up as much
of the foam
as possible
in one day.
Basements
Many of the
air leaks in
a basement
can be found
around the
rim joist
area. Some
cracks can
also be
spotted when
it's light
outside and
darker in
the
basement.
Check around
basement
windows,
plumbing
penetrations,
gas lines,
and dryer
vents. Make
sure the
outside
flapper on
your dryer
vent closes
and is not
obstructed
with lint.
If you have
basement
moisture
problems, be
sure to take
care of them
before
sealing
leaks.
Clean and
caulk
wherever air
penetrates.
Around the
rim joist
caulk the
joint where
the wood
sill plate
meets the
foundation
wall (1),
the top and
bottom edges
of the rim
joist (2 and
3), and the
edge of the
floor
baseboard
(4). Butyl
rubber or
pure
silicone
caulk
provide good
elasticity,
adhesion,
and
durability
in these
spots.
Expanding
foam can be
used for
larger
cracks.
Attics
Attics have
been proven
to be one of
the worst
culprits for
air leakage.
Time spent
here can be
more
productive
than any
other area
in your
home.
If your
attic is
accessible,
the
elimination
of leaks
should be
performed
inside of
the attic as
well as from
the ceiling
below. Seal
and insulate
all ductwork
in the attic
or
crawlspaces.
Check the
tops of
partitions
and end
walls, and
look closely
around
chimney and
vent
penetrations.
From below,
in the
living area,
look for
cracks in
the ceiling,
recessed
lights, and
gaps around
molding and
drywall.
Choose a day
that is not
too cold and
not too hot
for your
work in the
attic. A
hard hat,
boards to
walk on, a
face mask,
flashlight,
protective
clothing,
gloves and a
good eye for
wiring are
essential.
Take special
care with
the attic
door - the
most
important
door in your
house to
weather
strip!
Follow the
same
procedure
used in
weatherizing
your
exterior
doors. Seal
all four
sides.
V-strip,
rope caulk,
or foam
weather
stripping
can be used.
Use
high-temperature
silicone
caulk around
chimneys. A
collar of
sheet metal
may also be
used to seal
large gaps
around the
chimney.
Caulk around
the
sheet-metal
to complete
the seal.
Pressurized
foam can be
used around
plumbing
stacks.
If
necessary,
use a broom
to
temporarily
brush aside
insulation,
exposing
other
potential
cracks or
penetrations
through end
walls and
partition
walls. Use
caulk and
plastic to
seal these.
Fireplaces
:
Fireplaces
draw a lot
of heat from
a home,
whether they
are in
operation or
not. You
might want
to
temporarily
seal the
fireplace
opening with
an
inflatable,
heavy vinyl
bag called a
"chimney
plug." Be
sure to
close the
damper
before
sealing the
fireplace.
Other
options are
to use
plastic or
an insulated
and
weather-stripped
panel (a
"fireplace
plug") made
of sheet
metal, wood,
or similar
material.
Checklists
For Leak
Sealing
For easy
printing,
click here
to load the
checklists
on a
separate
page.
Air Leakage
Survey
Check off
the areas
that need
leak sealing
in your
home...
WINDOWS &
DOORS: ___
broken or
loose panes
___ trim,
frames,
jambs, and
sashes ___
storm
windows
WALLS: ___
switches and
outlets ___
electrical,
phone line
and TV
antenna ___
pipes/plumbing
___
baseboard
BASEMENTS:
___ rim
joist ___
windows ___
plumbing &
gas lines
___ dryer
vents ___
cracks in
brick
ATTICS: ___
attic door
___ plumbing
stacks,
chimneys and
vents ___
recessed
lights and
wiring ___
ceiling
cracks ___
tops of
walls
cavities
Leak Sealing
Tools &
Equipment
___ scissors
___ rags ___
caulk gun
___
screwdriver
___
measuring
tape ___
flashlight
___ leather
gloves ___
broom
(optional)
___ wire
brush ___
hard hat (in
attics) ___
utility
knife ___
safety
glasses* ___
dust mask*
___ sponge
___ boards
to walk on
in the attic
*when
working with
insulation
Materials
___ silicone
caulk ___
acrylic
latex caulk
___ silicon
acrylic
caulk ___
butyl rubber
caulk ___
v-strip
weather
stripping
___ rope
caulk ___
expanding
foam sealant
___
non-expanding
foam sealant
___ backer
rod sill
sealer ___
aluminum
tape (for
ductwork)
___ door
sweeps ___
fiberglass
insulation
___
polyethylene
tape for
cracks in
windows or
doors ___
duct tape
for
temporary
use only ___
electrical
switch and
socket plate
sealers
(gaskets)
___ clear
window
plastic with
track or
double-sided
tape
Also
check out
our
Manufacture's
Products
page
