Setting up a hardwood order
The flooring calculator starts here with ¾ in solid strip, 2¼ in wide, nailed down over a 13 × 16 ft room and a 4 × 12 ft hall. Pick what you are really laying: solid or engineered boards, nail-down, glue-down or floating, and the board thickness. Those three choices change the waste allowance, the fixings and the gap at the walls, so the result lists all of them next to the cartons.
Type the carton’s coverage from the label. Hardwood usually comes in random lengths, so the board length is optional: with it, the fastener count adds one for each board end.
What each choice changes
Waste follows Bruce’s instructions: 5% straight, 10% diagonal, and 10–15% for solid boards glued down (the calculator uses 10% and 15%). Herringbone and chevron are counted board by board instead; see the herringbone page.
Nail-down shows a range of cleats or staples from the NWFA schedule for your boards’ thickness and width. ¾ in solid strip under 3 in wide is fixed every 8–10 in, and ¾ in plank 3 in and wider every 6–8 in. Thinner solid boards need more: over ½ in and under ¾ in every 6–8 in, ½ in and thinner every 3–4 in, and 5/16 in strip is top-nailed with one brad per inch of width every 6½–7 in. Engineered boards 5/8 in or thicker take one every 6–8 in, thinner engineered every 3–4 in. Glue-down shows gallons and 4-gallon pails from Bostik’s coverage for your board type. Floating shows underlay with 10% added, the allowance Junckers gives for its foam.
The gap at the walls
Wood moves with the seasons, so every hardwood floor needs space at the walls, doorframes and pipes, later hidden by skirting or shoe moulding. The calculator takes the NWFA’s rule, a gap equal to the board’s thickness. For a floating floor it also works out Kährs’ figure from the floor’s width across the boards and keeps the larger. The perimeter figure is the length of trim that covers the gap: type the length where two areas meet, such as the edge between this room and its hall, so that edge isn’t counted as two walls, then take off the doorways.
Before the boards go down
The NWFA ties acclimation to moisture rather than to the calendar: a wood subfloor should be no more than 4 points wetter than solid strip under 3 in wide, and no more than 2 points wetter than plank 3 in and wider. Bruce asks for 60–80 °F and 30–50% humidity for 14 days before and during installation of its solid floors. Check the wood and the subfloor with a moisture meter before nailing.
Fixings and gap for 500 sq ft of hardwood
Fasteners at the NWFA spacing for each board's thickness and width (without the extra ones at board ends); 5/16 in strip is top-nailed with one brad per inch of width, rounded up; adhesive at Bostik GreenForce's adhesive-only coverage, and the gap at each wall: the board's thickness when nailed or glued, and for a floating floor the larger of that and Kährs' 1.5 mm per metre of width (at least 10 mm) for floors 4, 8 and 10 m wide.
| Boards | Nail-down | Glue-down | Gap, nailed or glued | Gap floating, 4 / 8 / 10 m |
|---|---|---|---|---|
| Solid strip, ¾ × 2¼ in | 3,200–4,000 · every 8–10 in | 14.3 gal · 4 pails | ¾ in | ¾ in / ¾ in / ¾ in |
| Solid strip, ⅝ × 2¼ in | 4,000–5,334 · every 6–8 in | 14.3 gal · 4 pails | ⅝ in | ⅝ in / ⅝ in / ⅝ in |
| Solid strip, ½ × 2¼ in | 8,000–10,667 · every 3–4 in | 12.5 gal · 4 pails | ½ in | ½ in / ½ in / 15 mm |
| Solid strip, 5/16 × 2¼ in, top-nailed | 13,715–14,770 brads, 3 a row · every 6.5–7 in | 12.5 gal · 4 pails | 5/16 in | 10 mm / 12 mm / 15 mm |
| Solid plank, ¾ × 5 in | 1,800–2,400 · every 6–8 in | 14.3 gal · 4 pails | ¾ in | ¾ in / ¾ in / ¾ in |
| Engineered, ⅜ × 5 in | 3,600–4,800 · every 3–4 in | 10 gal · 3 pails | ⅜ in | 10 mm / 12 mm / 15 mm |
| Engineered, ½ × 7½ in | 2,400–3,200 · every 3–4 in | 10 gal · 3 pails | ½ in | ½ in / ½ in / 15 mm |
| Engineered, ⅝ × 7½ in | 1,200–1,600 · every 6–8 in | 12.5 gal · 4 pails | ⅝ in | ⅝ in / ⅝ in / ⅝ in |
Waste allowance by fitting
| Boards and fitting | Straight | Diagonal | Source |
|---|---|---|---|
| Solid, nailed or floating | 5% | 10% | Bruce, solid ¾ in instructions |
| Solid, glued down | 10% | 15% | Bruce: "10-15% for glue down" |
| Engineered, any fitting | 5% | 10% | Bruce, engineered instructions |
| Junckers solid on clips | 2–3% | – | Junckers Clip floors instructions |
Sources, checked September 2026: Bruce, solid ¾ in installation instructions and engineered installation instructions; National Wood Flooring Association, Installation Guidelines (2019), nail-down chapter and acclimation chapter (copies hosted by flooring dealers); Kährs, wood flooring installation guide (archived copy); Bostik, GreenForce data sheet; Junckers, Clip floors instructions; Bruce, solid hardwood.