Insulate as you would any exterior wall with insulation that includes a vapor retarder.
Insulating attic over garage faced or unfaced.
Unfinished or uninsulated attics need a layer of protection against air migration.
You can also get loose fill fiberglass which it suitable for blowing into a garage attic space above a finished ceiling.
If the heat can not escape from the attic it will migrate down into the garage in which case insulating the attic of the garage will help a little.
Creating a moisture barrier.
If the walls and ceiling will remain open not covered with drywall or plywood it s a good idea to use paper faced or encapsulated fiberglass bats that are wrapped in a plastic film.
The best choices for this type of application include comforttherm kraft faced or unfaced with a separate vapor retarder film placed over the insulation.
The same applies to faced unfaced and other kinds of insulation products.
For many contractors the decision to use one kind of insulation over the other depends solely on preference rather than a by the book decision making process.
After insulating the attic of your garage your garage will be the same temperature as the outside in the shade.
Plan to pull up the flooring and layer new insulation on top of the old.
Insulating the attic above the garage will help keep temperatures in the garage a bit more stable but it won t have any appreciable effect on energy bills.
To insulate the floor of the room above the garage seal the space between the floor of the room and the ceiling of the garage and the top plate and the header joist with insulation.
What is the right insulation for an attic.
If you do not heat or cool an area it is considered to be unconditioned.
If the attic doesn t have any existing insulation use faced insulation with the paper facing toward the heated living space.
Before installing insulation in garage walls clear the area inside your garage of any obstacles.
If your home s hvac system does extend into the garage then the attic above it should be insulated as it would for any other room of the house.
This will serve the same function of keeping hot or cold air inside the garage as it does for the rest of the house.
As a result of evaporation people breathing and plant respiration air carries some.
But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates.
When adding more insulation to an attic that already has insulation use unfaced insulation.
When you should insulate the garage.
Because the simplest and cheapest way to insulate an attic is to add material to the floor.
But in this application going over other insulation you do not need faced insulation.