Abstract: A dust gap spacer is provided for use along a baseboard at the foot of a wall where the wall intersects a floor. The spacer is installed prior to the installation of wall to wall carpeting. The dust gap spacer is of a uniform L-shaped cross section throughout and is formed with a raised shoulder adapted to reside at the foot of a wall and a ledge in contact with the floor and extending away from the wall and from the shoulder at a height lower than the shoulder. A tack strip is located atop the ledge and the peripheral margin of the carpeting resides atop the tack strip and in abutment against the shoulder. The dust gap spacer permits an upright vacuum cleaner to clean the entire carpeting, including the peripheral margin thereof, and provides a decorative trim strip surrounding the carpeting at the base of the wall. The dust gap spacer eliminates an unsightly dirty marginal border around the carpeting.