6×20' framed floor on concrete piers · Updated May 2026
| Item | Spec | Qty | Unit | Total |
|---|---|---|---|---|
| QUIK-TUBE 8" × 48" form | 8" dia., 48" length — fits 4' hole exactly, no cutting needed | 12 | $11.48 | $137.76 |
| 80 lb. concrete mix | ~4,000 PSI; yields ~0.6 cu ft/bag; 3 bags per pier | 36 bags | $6.47 | $232.92 |
| ABA ZMAX adjustable post base (4×4) | 18-gauge ZMAX galvanized; adjustable standoff; ACQ compatible; set anchor bolt in wet concrete | 12 | $16.30 | $195.60 |
| Quikrete 50 lb. All-Purpose Gravel | Pier base drainage bed; ~1.3 bags per pier | 16 bags | $6.97 | $111.52 |
| 8" auger rental (4 hrs) | Power auger for 8"-dia. × 4'-deep holes; 4 hrs sufficient for 12 piers | 1 | $67.00 | $67.00 |
3 bags/pier (36 total) fills each 8"-dia. × 48" tube with margin — ~1.4 cu ft/tube vs ~1.8 cu ft yield. | Holes already augered.
Cure timeline: 24 hrs — forms can be removed · 3–5 days — drill and install wedge anchors · 7 days — safe to start framing (70% strength ≈ 2,800 psi) · 28 days — full 4,000 psi. No need to wait 28 days for a shed.
Hot/dry weather: mist pier tops and cover with plastic for first 24–48 hrs to prevent surface cracking. Below 40°F: do not pour — use insulating blanket or reschedule.
Leveling: Use cross-line laser level, water level, or string line to verify all pier tops within ½" of each other before concrete sets. ABA ZMAX adjustable post base provides up to ½" vertical fine-tuning via leveling nut on anchor bolt.
| Item | Spec | Qty | Unit | Total |
|---|---|---|---|---|
| 2×6×8 PT — long side beams (doubled 2-ply) | UC4B; actual 1½" × 5½"; 3 boards/ply × 2 plies × 2 sides = 12 boards. Ply 1 splices at 8' & 16'; Ply 2 splices at 4' & 20' | 12 boards | $10.48 | $125.76 |
| 2×6×8 PT — end caps | UC4B; cut to 6'; single ply sufficient for short span | 2 boards | $10.48 | $20.96 |
| 3-1/4" × 0.131" galvanized framing nails (750-ct) | 21° plastic collated, exterior galvanized — safe for PT lumber; Freeman PFR2190 compatible; covers beam lamination (2 rows staggered every 16" OC) + wall framing; shared box — costed in wall/roof list | — | — | see wall list |
No center beam needed — 2×6 joists at 16" OC span 6' without mid-span support (well within SYP #2 allowable). Doubled beams eliminate single-point splice failures and prevent lateral rolling during construction.
| Item | Spec | Qty | Unit | Total |
|---|---|---|---|---|
| 2×6×12 PT — joists | #1 Ground Contact PT; 16" OC; cut to 6' — 2 joists per 12' board, zero waste; 14 interior joists | 7 boards | $16.48 | $115.36 |
| Simpson Strong-Tie LUS26 ZMAX face-mount joist hanger for 2×6 | LUS26; 18-gauge ZMAX galvanized; 2 per joist (one each end) = 28 total | 28 | $1.98 | $55.44 |
| SD connector screw #9 × 1-1/2" (100-pk) | Strong-Drive; 1/4-hex drive; for joist hanger fastening; ~8 screws/hanger × 28 hangers = 224 screws needed | 3 packs | $16.65 | $49.95 |
Joists hung flush with beam top (not stacked on top) to keep floor height at target. ABA ZMAX post bases handle beam-to-pier uplift; LUS26 hangers handle joist-to-beam uplift — no additional hurricane ties needed for floor.
| Item | Spec | Qty | Unit | Total |
|---|---|---|---|---|
| 3/4" PT plywood 4×8 (non-T&G) | Ground Contact rated; PS 1-09; non-T&G acceptable at 16" OC — all panel edges land on joists; 5 sheets covers ~126 sq ft + waste | 5 sheets | $56.48 | $282.40 |
| 10 oz. construction adhesive | PL Premium or equivalent; applied to joist tops before laying sheets | 3 tubes | $3.48 | $10.44 |
| #9 × 3" construction screws — 1 lb. box | Star drive, dual flat head, coarse thread; ~65/box; 5 boxes ≈ 325 screws; fasten every 6–8" at edges, 12" in field | 5 boxes | $10.88 | $54.40 |
Orientation: Run 8' dimension along the shed length — this is perpendicular to the joists (APA standard). The 4' dimension spans across the width; panel edges at 0' and 4' both land on joists. No T&G or H-clips needed at 16" OC.
Stagger seams: Row 1 starts at 0' (full 4' wide panels). Row 2 starts 2' in (2' wide strips cut from full sheets). Seams never align between rows.
Layout (5 sheets): Sheet 1 & 2 → Row 1, full 4'×8'. Sheet 3 → Row 1 end, cut to 4'×5' (3' offcut). Sheet 4 → rip to two 2'×8' strips for Row 2. Sheet 5 → cut Row 2 end pieces.
Apply construction adhesive to all joist tops before laying each sheet. Fasten 6" OC at edges, 12" in field. Stagger end joints by at least 4'.
| Item | Spec | Qty | Unit | Total |
|---|---|---|---|---|
| Woven landscape fabric 4×50 ft. | Heavy PP woven weed barrier; 1 roll = 200 sq ft; covers 6×20' (120 sq ft) with overlap to spare | 1 roll | $17.79 | $17.79 |
| Cut-N-Treat wood preservative — 1 qt. | Apply to all field-cut PT lumber ends immediately after cutting | 1 | $14.98 | $14.98 |
| Item | Spec | Qty | Unit | Total |
|---|---|---|---|---|
| Home Depot delivery | Standard delivery | 1 | $79.00 | $79.00 |
| Item | Spec | Qty | Unit | Total |
|---|---|---|---|---|
| Motovera Self-Leveling Cross-Line Laser Level w/ Tripod | 100ft range; green laser (visible outdoors); self-leveling; IP54 waterproof; used during pour to verify all pier tops within ½" — the ABA ZMAX adjustable bases handle remaining height variation | 1 | $39.99 | $39.99 |
| Concrete Piers | $744.80 |
| Beams | $146.72 |
| Floor Joists | $220.75 |
| Decking | $347.24 |
| Ground Prep | $32.77 |
| Delivery | $79.00 |
| Tools | $39.99 |
| Total | $1,611.27 |