Carpet Installation
Carpet installation rewards understanding of stretch, seam construction and pile direction. The exam asks about tack strip placement, stretching force, seam sealing, stairs and modular carpet.
Stretch-in systems
- Tack strip goes 1/4-3/8 in. from the wall, pins angled toward the wall and the floor; never reuse old, bent strip.
- Cushion is stapled with the correct staple length so staples do not poke through, and cushion seams should not align with carpet seams.
- Power stretch to roughly 1-1.5%, enough that the carpet is tight and will not wrinkle. A knee kicker is for positioning and fitting, not for final stretch.
- Stretch along the length first, then the width; trim and tuck with a stair tool, then install base.
Seams
- Match rows and pattern; cut along a row for a nearly invisible seam.
- Use seam tape and iron at the correct temperature, seal the edges with seam sealer, and roll with a seam roller.
- Keep seams out of direct sunlight, high-traffic lanes and doorways.
Pile and pattern
- Keep pile direction consistent across the installation; a reversed drop reads as a shade difference.
- Patterned carpet requires the match calculated before cutting, with waste added accordingly.
Stairs
- Waterfall (stapled through tread and riser) or cap-and-band (upholstered); tack strip on each tread, staples under the nosing, and a tighter stretch on stairs.
Modular carpet
- Quarter-turn or monolithic; follow the arrows on the back; adhesive or peel-and-stick per specification; roll after installation.
Worked example
A 15 ft-wide room with 12 ft goods. A seam is unavoidable. It is placed 3 ft from one wall so the 12 ft piece covers the traffic side, kept out of the doorway and away from the window wall, rows matched, edges sealed, and the whole floor power-stretched before the seam is rolled.
Traps
- Under-stretching, which causes wrinkles and buckling, especially in humid weather.
- Reusing tack strip, or leaving the wrong gap at the wall.
- A seam that is not sealed, so it frays and opens.
- An iron too hot, melting backing and leaving a hard visible line.