For the same reason insulation shouldn t touch the roof s underside.
Insulating the garage roof.
Adding insulation won t make your garage a perfect temperature by itself but it will take the edge off the freezing winters and the sweltering summers.
Don t insulate your garage walls and ceiling without insulating the big garage door too.
One of the best methods you can use if you want to regulate the temperature of your garage is to insulate the garage roof.
Staple plastic or foam baffles to the roof sheathing near the eaves to keep the material away.
The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow.
There should be a continuous ridge and soffit ventilation.
I wrote a big article discussing whether you should insulate your garage.
In essence insulation materials serve as a barrier that doesn t permit heat to move through them.
If you have a flat garage roof and an attic above you can install the garage insulation from below using a standard ladder.
The regulating temperature has positive effects on your cooling and heating costs.
A garage attic also should be insulated is if there is an air conditioned room above the garage.
The task of insulating a garage roof is not hard to complete if you follow a few tips and hints.
In general if you re not heating or cooling your garage there is little benefit to insulating the ceiling because there s no costly heated or cooled air to keep in.
If you are insulating the garage ceiling not only by the truss level but also up by the roofline then you must leave at least 1 1 2 to two inches of air between the fiberglass and the underside.
The insulation will keep the naturally hot or cold air in the garage and the artificially warmed or cooled air in the room above it.
You can buy insulation kits for standard metal garage doors or you can cut pieces of rigid foam insulation to fit each door panel section.
Keep in mind that the structural metal ribbing of garage doors is an excellent conductor of heat and this typically doesn t get insulated.
However if you have a cathedral style garage roof you will need a scaffolding to get into the upper areas of the roof.
If your garage is attached to your house you will notice a big difference in your home s temperature as well.
In either case you will need to follow the general steps below to insulate your garage roof.
Regulate your garage s temperature all year by installing insulation.
Insulating the garage roof will prevent heat from transferring from the roof into the garage during the summer and prevent warm air in your garage from being transferred outside through the roof keeping your garage at a stable temperature.