Insulation: never easier

Many homeowners look at the garage as the largest room of their house and ask: Why can't we make better use of this space year-round? Great question!

Sadly, too many garages are beastly hot in the summer and icy cold in the winter. Let's see if we can change that.

The detached 2¹⁄₂ -car garage shown here got an upgrade with batts of R-13 insulation in the walls and ceiling. The insulation and a new natural-gas garage heater will allow the homeowners to keep the garage interior 40°F or warmer all winter. The heated space transforms into a retreat for their kids to play in inclement weather, and working in the garage in the winter no longer requires gloves and a stocking cap.

For this garage project, Johns Manville formaldehyde-free encapsulated batts were selected. Because the insulation is wrapped in plastic, the homeowners and friends who helped install the insulation experienced minimal itch and dust associated with traditional kraft-faced (paper-covered) products. (Safety glasses, nuisance dust masks, and long sleeves are still recommended.) According to the company Web site (jm.com), the poly-faced vapor retarder is twice as resistant to moisture as kraft-faced products. Thus, no vapor barrier was required.

This project qualified for federal tax credits for energy-saving projects. Before you begin your insulation project, check with your utility company to see if tax credits or rebates are available.

To provide unobstructed passage of air between the soffits (see steps next page) and the roof vents, attach vent chutes between the rafters. Industry guidelines suggested six pairs of vent chutes (12 rafters vented).

A pneumatic nailer makes quick work of securing ³⁄₄ "x4x8' sheets of oriented strand board (OSB) to the ceiling. Time to line the roof and gable ends: 18 man-hours.

1. Mark 4x16" openings for each of the under-eave vents in each soffit (front and back of this garage; six total). Drill 1" start holes in two corners of each opening.

2. With a jigsaw and a standard blade (10-12 tpi for hardboard), cut the vent opening. Be sure to wear eye protection to avoid getting sawdust in your eyes.

3. Attach the louver for each vent. The louver allows cooler air to flow through the insulated rafters and out the roof vents--important on hot summer days.

1. With a sharp utility knife and a 24" carpenter's square, cut the insulation batts to length. For a clean, fast cut, push down on the square to compress the batt while you cut.

Insulation will dull a knife blade quickly; this homeowner changed blades five times before the project was completed.

2. Pat the insulation batts into place. (In some regions of the country, you may find batts precut for 8' or 9' walls, which saves installation time.)

3. Staple the batt to each cavity, placing the staples every 8-10". To get full benefit of the insulation R-value, minimize compression when you staple the batts to the wall studs.

4. Temporarily run insulation around utility boxes, leaving at least 12" unstapled above and below the box. But don't forget to remedy this energy-waster, as shown on next slide.

5. With a utility knife, cut around the box and remove a fluff of insulation (about equal to the utility box) and smooth out insulation surrounding the box.