2×12 Stringer Lumber Haul for a 108 Inch Stair
Lumber delivery for the 9 ft floor-to-floor stringers.
Formula SSC-2026.1
IRC check pass
Risers / treads
14 / 13
Riser inside 4 to 7.75 in
Exact riser
7 11/16 in
195.9 mm
Total run
10 ft 10 in
3,302 mm
Stringer length
14 ft 1 in
Order 16 ft 2x12
Incline
39.72°
Square 7 11/16 in rise · 10 in run
Stringers @ 16 in
3
Throat 5.14 in on a 2x12
Rise, run, and the incline are scaled from the live riser and tread. Framing-square gauges match the exact riser and the tread depth.
| Item | Net | Waste | Order | Unit price | Line total |
|---|---|---|---|---|---|
| 16 ft 2x12 | 14.73 ft cut | end cuts included | 3 boards | USD | $100.80 |
| Stringer delivery weight | 134 lb | — | 61 kg | 2.8 lb/ft planning weight | — |
| Target | Risers | Exact riser | Run | Angle | Check |
|---|---|---|---|---|---|
| 7 1/4 in | 15 | 7 3/16 in | 11 ft 8 in | 37.6° | Pass |
| 7 1/2 in | 14 | 7 11/16 in | 10 ft 10 in | 39.7° | Pass |
| 7 3/4 in | 14 | 7 11/16 in | 10 ft 10 in | 39.7° | Pass |
Show the deterministic formula
Risers = round(total rise ÷ target rise). Exact riser = total rise ÷ risers, reported to the nearest 1/16 in and in millimeters. Treads = risers − 1. Total run = treads × tread depth.
Diagonal = hypotenuse of stringer rise and total run. A dropped header uses total rise minus landing thickness. Stock is the next 8, 10, 12, 14, 16, 18, 20, or 24 ft board.
Stringers = floor(width ÷ 16) + 1, with a minimum of 2. Throat ≈ 11.25 − (riser × tread) ÷ hypotenuse.
Contractor sign-off
Project: 2×12 Stringer Lumber Haul for a 108 Inch Stair
Prepared by
Date
Verified by (PE / electrician / inspector)
License number
Signature
This sheet is an estimate for ordering and layout discussion. It is not a sealed design. Confirm the quantities with a licensed local professional and the authority having jurisdiction before you buy or build.
Engineering notes
The rise is 108 in, the target is 7.5 in, and the tread is 10 in. The bill names the stock 2x12 length and the number of stringers at 16 in on center. Haul weight uses 2.8 lb per foot of pressure-treated planning weight times the stock length times the stringer count. Kiln-dried spruce is lighter. The price field is dollars per foot, so a 16 ft board is that rate times 16.
Code reference
IRC R311.7.5.1 limits risers to 7.75 in and R311.7.5.2 requires at least a 10 in tread. Confirm local amendments, guards, and headroom.
Field questions
- What length 2x12 should the yard pull?
- The shortest stock board from 8 through 24 ft that covers the diagonal plus end waste. The shopping line shows that length.
- How is the haul weight figured?
- 2.8 lb per foot times the stock length times the number of stringers. It is a planning weight for treated 2x12, not a scale ticket.
- Does a dropped header shorten the board?
- It can. The stringer rise drops by the landing thickness, and the diagonal follows. This preset is a standard interior mount.