Insulating Your Remodeled Room

I need more living space so I am building a detached garage and am going to convert the basement and old garage into rooms. What options do I have for insulating and finishing the walls?—Michael J.

Building a new garage and converting the old garage and basement makes a lot of sense. It is less expensive overall to build a new brick, framed, or block garage than to make a major room addition.

You have many options for converting the basement and old garage, but whatever method you choose, you will have to add insulation to the walls and you may want to insulate the floors. This is not only for comfort and lower utility bills, but building codes in most areas require a certain level (R-value) of wall insulation. Check the codes—you may need a permit for the conversions along with the one for the new garage.

The method you use to finish the basement walls will probably be different than for the garage. There are some very nice basement wall finishing systems available that include insulation and attractive wall panels.

These wall finishing systems are designed to handle the higher moisture content from basement walls, but they may work aboveground too. The only problem may be that the aboveground insulation level required by code may be higher than for basements, so the system may not meet the code. Also, the moisture barriers may not be positioned properly for aboveground use.

If you choose to do the insulation yourself and not use a preassembled system, you will probably have plenty of room in the basement for standard batt insulation. This is your lowest cost option. If space is limited, as in your old garage, use rigid foam insulation.

Rigid foam insulation has about a 50 percent higher R-value per inch thickness, so the walls can be thinner and still meet code. Some rigid foam insulation sheets use a closed-cell material, so they function well as a vapor barrier and will resist degradation by moisture or humidity. Some types have special multi-layer moisture-resistant coverings on each side so they can also be used in the basement.

Shop for rigid foam panels with notched edges designed specifically for finishing masonry walls. These have notches to allow the furring strips—thin wooden strips used for attaching paneling to other wall material—to be recessed for a smooth surface. Most foam insulation should be covered with drywall for fire safety reasons, but again, check your local codes.

If you want to do the work yourself and your garage has a window you will want to open at times, you might consider movable wall insulation panels.

The basic design uses four panels. The two outer panels are fixed to the garage wall and the center ones slide open if you want to open the window. Windows have low insulation value, so if you are not going to look outdoors or need natural light, it is better to have them covered with insulation. Cover the panels with drywall for fire safety and then finish them with fabric, paint, or wallpaper to match the room decor.

For most do-it-yourselfers, it is easier to hang the panels from the top rather than having them roll in tracks on the floor, which would require more careful fitting. The small gap at the bottom will not be a major energy loser; however, installing a sealed bottom track would be better. Caulk the fixed outer panels and weatherstrip the edges so they seal well against the movable panels.

Write for Utility Bills Update No. 748 for a buyer’s guide of insulation system/material manufacturers. Include $3.00, a business-size SASE, and Update number. Mail requests and questions to James Dulley, Kentucky Living, 6906 Royalgreen Drive, Cincinnati, OH 45244. Go to www.dulley.com to instantly download.