Attic Crawl Space

Attic Crawl Space Insulation, Storage and Doors

By Mark J. Donovan




When finishing an attic triangular shaped attic crawl spaces are often created. A crawl space is frequently formed when a knee wall is constructed in the attic to establish the lowest level of the finished roof line of the finished attic space. Attic crawl spaces are notorious for having insufficient insulation in them. Also, attic crawl space doors are typically handmade on the jobsite and often leak like sieves letting in cold air drafts.

If you have a room with attic crawl spaces as I’ve described, and there is a crawl space door, inspect the space for adequate crawl space insulation.

Make sure the knee walls have proper faced batting or rolled insulation installed in between each stud bay. Also make sure the paper facing is up against the drywall of the finished attic. If paper faced insulation was not used, make sure there is a plastic vapor barrier up against the drywall, with the insulation placed over it.

In addition, make sure there is attic crawl space insulation in the lower level ceiling joist bays. If there is a plywood subfloor on the attic crawl space floor you may want to cut a section of the subfloor out to confirm that there is insulation underneath it. If there is not, then attic crawl space insulation should be placed over the subfloor. You can use either batt or blown in insulation.
Make sure to install sufficient attic crawl space insulation for your particular region of the country.
Make sure to adequately insulate crawl spaces when finishing an attic.

The Department of Energy has an excellent website that specifies the recommended amount of insulation that should be installed in the various areas of a home for the different regions of the country. In general you should install between R-30 and R-49 insulation in the attic, depending upon where you live. In warmer climates R-30 insulation is adequate, however in colder climates R-49 should be used.

Also inspect the attic crawl space door. If you feel cold drafts emanating from the door frame, install weatherstripping around the interior door frame to create an air tight seal. You may also want to put a bottom door skirt on the attic crawl space door to prevent cold drafts from coming in from underneath it.

If there are any plumbing supply lines in the attic crawl space, make sure they are insulated with foam pipe insulation. In addition, if the pipes are in the knee wall stud bays, install additional rolled or batting insulation over them. I once had a copper supply line pipe burst that was in an attic crawl space. It created a lot of water damage to the lower level of the home. When inspecting and repairing the pipe I noticed it had no foam pipe insulation around it, and only minimal rolled insulation placed over it.

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Though attic crawl spaces can be major sources of home heating loss, they do have their benefits, particularly when they are insulated properly. Attic crawl space storage is one key benefit. Unlike many attics, an attic crawl space is typically easier to get into, assuming there is an attic crawl space door.

Consequently they are great for storing holiday decorations and other items that are used infrequently. An attic crawl space is also easier for housing some types of HVAC equipment, thus freeing up space in the main attic, basement or utility area. Attic crawl spaces are also ideal for integrating in closets or built in book cases.

So before the cold weather hits again make sure your attic crawl space has adequate insulation and a tightly sealed door. By doing so your home will maintain a more constant and comfortable temperature and you will save on home energy costs.



For help on Attic Conversion and Attic Renovation Projects, see HomeAdditionPlus.com’s Attic Conversion Bid Sheet. The Attic Conversion Bid sheet will help to ensure that you hire the right contractor so that your attic conversion project is built correctly, on time and budget.

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