Read This Before You Finish Your Basement

What to Inspect (and Fix) Before You Start

• Test for moisture by taping 2-foot squares of plastic sheeting to the floor and walls. Wait a couple of weeks. If condensation forms underneath, your foundation's not sealed. If droplets form on top, your basement needs dehumidifying.


• Use an awl to probe for rot and insect damage in floor joists, rim and header joists, the sill plate, and wood-framed windows.


• Check floor joists for sagging by climbing a ladder until you're nearly eye level with the underside of the joists. Look across them (perpendicular to their direction) to see if any are out of line.


• Have a pro check fuel-burning equipment and your house's ventilation system to ensure that you won't have carbon monoxide buildup below grade.