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insulating garage/basement ceiling

I recently bought a house in the Birmingham Al area and have a question about insulation. The house has a basement/garage and over 50% of the walls are exposed(steep hills). Would it be beneficial to insulate the ceiling of the garage/basement  to help with heating and cooling? The floor are hardwood and I've noticed it's cool inside my garage when I get out of my car in the afternoons but once I walk upstairs into the living area I notice its definitely warmer than the garage. I think a lot of the cooler air is dropping from the living area into the basement and causing the air conditioner to run all day.

Re: insulating garage/basement ceiling


Types of Insulation for Your Garage

Garage Insulation Basics
It pays to insulate your garage if you're adding heat, whether on a permanent or as-needed basis. If you're not adding heat, there's little point in insulating. It's a popular misconception that insulation adds warmth. In reality, insulation merely slows the transfer of heat through the insulated barrier (wall, ceiling, floor, etc.).

Fiberglass Insulation
Fiberglass is the most commonly used type of insulation in garages (just as it's the most popular type in homes). It's sold in pre-cut batts and long blankets that fit between wall studs and ceiling joists. You can also get loose-fill fiberglass, which it suitable for blowing into a garage attic space above a finished ceiling.

Cellulose Insulation
Cellulose is a loose-fill insulation that is growing in popularity. Made primarily from recycled newspapers and treated with a fire retardant, cellulose is usually blown into wall and ceiling cavities with a special blowing machine that also aerates the cellulose and fluffs it up. Blowers can be rented at many tool rental stores, and home centers will sometimes loan you a free one if you buy your cellulose from them.

Rigid Foam Insulation
Rigid foam comes in 4 x 8-foot sheets and thicknesses of 1/2 inch to 4 inches. The most common materials include expanded polystyrene (similar to Styrofoam), extruded polystyrene, and polyisocyanurate. Rigid foam offers a high R-value per inch of thickness and can be cut to fit almost any space. It's a good choice for thin walls and for insulating garage doors. If you're turning the garage into living space or a full-time workspace and want to insulate the floor, one option is to use rigid foam covered in plywood or other subfloor material.

Garage Door Insulation
Don't insulate your garage walls and ceiling without insulating the big garage door, too. 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. As a result, the overall thermal performance of the door will be well below the rated performance

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