Carpet

Tack Strip Layout and Installation

CRI 105 rules for tack strip: minimum size, pin direction, gully width, fasteners per piece, doorways, radiant heat and stairs.

Updated · 2 min read

Tack strip holds all the tension a power stretcher puts into the carpet. If the strip is too narrow, loosely fastened or set too far from the wall, the carpet relaxes and wrinkles. The requirements below come from the residential installation standard, section 11.1 unless noted.[1]

Strip size

Not every strip on the shelf meets the standard.

  • Minimum size is 1" (25 mm) wide and 1/4" (6 mm) thick.[1] Common 7/8" retail strip falls short of this.
  • Rooms over 30 ft need 1-3/4" architectural strip with three rows of pins, or two rows of conventional strip.[1] One CRI bulletin gives 2" for architectural strip.[2]

Placement

How the strip sits against the wall decides how well it holds.

  • Pins angle toward the wall.[1]
  • The gully between strip and wall should be a little less than the carpet thickness, and never more than 3/8" (9 mm).[1]
  • Don't run strip across door openings or sills; use a transition there. See Transitions and thresholds.
  • Don't staple the carpet to the strip.[1]

Fastening

Short pieces are where strip usually lets go.

  • Every piece needs at least two fasteners, including short pieces at corners and doorways.[1]
  • Use nails or fasteners suited to the substrate: wood nails on wood, concrete nails or adhesive on slab.
  • Over radiant heat, use adhesive, never nails or screws.[1]

Stairs

Stairs use a different gully and pin direction (section 15.2).[1]

  • On treads, pins point toward the riser.
  • On risers, pins point down.
  • The gully at the tread and riser corner is a little less than twice the carpet thickness.[1]

More in Carpeting stairs.

Step by step

Set the gully first; everything else follows from it.

  1. Check the carpet thickness to set your gully.
  2. Lay strip around the room with pins toward the wall, keeping the gully consistent.
  3. Cut pieces to fit corners and obstacles; don't leave gaps longer than the strip can bridge.
  4. Fasten each piece with at least two fasteners.
  5. Skip door openings; plan the transition there.
  6. Install pad inside the strip, not over it.

Common mistakes

Most strip problems show up later as wrinkles along one wall.

  • Narrow retail strip in a big room. It can't hold the stretch.
  • Gully too wide. The carpet can't be tucked tight.
  • One nail per short piece. It rotates under tension.
  • Nailing over radiant heat.

Tools and products we carry

These cover fastening strip and finishing edges at hard surfaces.

References

  1. CRI 105: Residential carpet installation standard
  2. CRI: Carpet wrinkles, buckles or bubbles

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