Johns Manville Guide to
Sealing Your Attic and
Insulating Your Home
JM Formaldehyde-free
building insulation
JM Formaldehyde-free
fiber glass insulation delivers superior thermal and
acoustical performance for the life of your home and improves indoor air
quality because its made without formaldehyde. We care about the health
and well being of those in the homes we insulate. Thats what motivates
us to develop innovative new products that make homes more comfortable,
safer and healthier for those inside. We removed formaldehyde from our
insulation because it was the smart thing to do. JM Formaldehyde-free fiber glass insulation does even more. It helps the environment because we use more certified post-consumer recycled content than any other major fiber glass insulation manufacturer.
We incorporate an average of 25% recycled contentat least 20% glass from recycled bottles from
curbside recycling programs and the remainder from post-industrial glassacross North America.* And
since its made without formaldehyde, there are no binder-related formaldehyde emissions coming from
our plants during manufacturing. Our fiber glass manufacturing plants are so clean, theyre the only
ones exempt from EPA Hazardous Air Pollutant regulations. * Recycled content is certified by Scientific Certification Systems. CONTENTS Locating Air Leaks 3 Locating Under-insulated Areas 5 Getting Started 7 Sealing Attic Air Leaks 9 Additional Sources of Attic Air Leaks 16 Adding Insulation 18 Use this guide to: 1. Learn how to find and seal hidden attic air leaks 2. Determine if theres enough insulation in your home, and find out how to add more to the: Attic
Basement
Crawl space
Floors
Exterior walls and garages 3. Make improvements safely and effectively CONTENTS Adding insulation and sealing air
leaks is the quickest, cheapest way
to a more energy-efficient home. Caution: Most attic air-sealing and home insulating
projects can easily be done by the DIYer. However,
if you have any questions, concerns or come
across a situation not covered in this booklet,
consult a professional. LOCATING AIR LEAKS 3 LOCATING AIR LEAKS You may have already noticed air leaks around
windows and doors, but often the more significant
leaks into the attic are harder to detect. These are
the leaks that raise your energy bills and make your
home uncomfortable. In cold weather, attic air leaks
act like a chimney, drafting expensive heated air up
into the attic and sucking cold air in all around your
homearound windows, doors and the rim joists.
In hot weather, the opposite occurs. Check for leaks
around plumbing fixtures, light fixtures, chimneys,
soffits and chaseways, which are often hidden
under insulation. An easy way to find an air leak is to
hold a tissue between two fingers
near the area and the draft will move
the tissue. You can also use a lighted
smoke pencil or incense stick. 2 3 1 Stopping the chimney effect Outside air drawn in through basement leaks is
worsened by the chimney effect created by leaks
in the attic. As hot air generated by the furnace rises
up through the house 1 and into the attic through leaks , cold outside air gets drawn in through basement leaks to replace the displaced air 3 . This makes your home feel drafty and raises energy
bills. By sealing attic air leaks, you are stopping the
chimney effect. It is like closing the end of a straw. Caution: When sealing the furnace pipe (which will
be encased in a metal sleeve), use high-temperature
caulk. Run a bead of high-temperature caulk around
the pipe sleeve and around the metal frame. Illustration
quality because its made without formaldehyde. We care about the health
and well being of those in the homes we insulate. Thats what motivates
us to develop innovative new products that make homes more comfortable,
safer and healthier for those inside. We removed formaldehyde from our
insulation because it was the smart thing to do. JM Formaldehyde-free fiber glass insulation does even more. It helps the environment because we use more certified post-consumer recycled content than any other major fiber glass insulation manufacturer.
We incorporate an average of 25% recycled contentat least 20% glass from recycled bottles from
curbside recycling programs and the remainder from post-industrial glassacross North America.* And
since its made without formaldehyde, there are no binder-related formaldehyde emissions coming from
our plants during manufacturing. Our fiber glass manufacturing plants are so clean, theyre the only
ones exempt from EPA Hazardous Air Pollutant regulations. * Recycled content is certified by Scientific Certification Systems. CONTENTS Locating Air Leaks 3 Locating Under-insulated Areas 5 Getting Started 7 Sealing Attic Air Leaks 9 Additional Sources of Attic Air Leaks 16 Adding Insulation 18 Use this guide to: 1. Learn how to find and seal hidden attic air leaks 2. Determine if theres enough insulation in your home, and find out how to add more to the: Attic
Basement
Crawl space
Floors
Exterior walls and garages 3. Make improvements safely and effectively CONTENTS Adding insulation and sealing air
leaks is the quickest, cheapest way
to a more energy-efficient home. Caution: Most attic air-sealing and home insulating
projects can easily be done by the DIYer. However,
if you have any questions, concerns or come
across a situation not covered in this booklet,
consult a professional. LOCATING AIR LEAKS 3 LOCATING AIR LEAKS You may have already noticed air leaks around
windows and doors, but often the more significant
leaks into the attic are harder to detect. These are
the leaks that raise your energy bills and make your
home uncomfortable. In cold weather, attic air leaks
act like a chimney, drafting expensive heated air up
into the attic and sucking cold air in all around your
homearound windows, doors and the rim joists.
In hot weather, the opposite occurs. Check for leaks
around plumbing fixtures, light fixtures, chimneys,
soffits and chaseways, which are often hidden
under insulation. An easy way to find an air leak is to
hold a tissue between two fingers
near the area and the draft will move
the tissue. You can also use a lighted
smoke pencil or incense stick. 2 3 1 Stopping the chimney effect Outside air drawn in through basement leaks is
worsened by the chimney effect created by leaks
in the attic. As hot air generated by the furnace rises
up through the house 1 and into the attic through leaks , cold outside air gets drawn in through basement leaks to replace the displaced air 3 . This makes your home feel drafty and raises energy
bills. By sealing attic air leaks, you are stopping the
chimney effect. It is like closing the end of a straw. Caution: When sealing the furnace pipe (which will
be encased in a metal sleeve), use high-temperature
caulk. Run a bead of high-temperature caulk around
the pipe sleeve and around the metal frame. Illustration
download Johns Manville Guide to Sealing Your Attic and Insulating Your Home
