General · G
Corrections
Every change that alters a published result is recorded here, with the sheet it affected and what the number used to be.
The log
| Date | Sheet | Was | Now | Effect |
|---|---|---|---|---|
| 2026-09-19 | S-101 Concrete Calculator | Unit weight 150 lb/cu ft and truck capacity 10 cu yd stated as facts; gravel base ordered with an unsourced +15% compaction allowance; bag yields credited to two manufacturers. | Unit weight and truck capacity are editable assumptions (formula rev. 1.1.0); base ordered at the sourced 0.89 load factor, about +12%; yields credited only to the QUIKRETE No. 1101 data sheet. | Base course order quantity drops about 3%. Concrete volume, bag counts and cost are unchanged at the default settings. |
| 2026-09-19 | S-101 Concrete Calculator | Control-joint spacing printed as 24 to 36 times the slab thickness with no upper limit, so a 6 in slab showed 12 to 18 ft and an 8 in slab 16 to 24 ft. | Both ends of the range are capped at 15 ft (formula rev. 1.1.1): NRMCA CIP 6 recommends, in the sentence after the multiple, that joint spacing be limited to a maximum of 15 feet. | Joint spacing shown for slabs 5 in and thicker gets shorter. Volumes, bag counts, truck loads and cost are unchanged. |
| 2026-09-19 | C-101 Gravel Calculator | One FAQ answer and one line of the mistakes list gave the in-place volume of the 100 by 10 ft, 4 in driveway example as 13.5 cu yd, and the shortfall from ordering the compacted volume from that figure. | 333 cu ft is 12.35 cu yd in place, as the worked example on the same page already showed; the shortfall reads 1.5 cu yd. | Page text only. The calculator, its order quantities and the worked example were already correct. |
| 2026-09-19 | S-101 Concrete Calculator | The compacted gravel base was ordered by dividing by Caterpillar's 0.89 bank-to-loose load factor, about +12%: that factor is the ratio between undisturbed and loose material, used here as a stand-in because the table publishes no compacted column. | The base is ordered at the labelled FHWA ratio 1.31 (formula rev. 1.2.0): 3,570 embankment over 2,730 loose lb/cu yd, Exhibit 5.1 A, gravel dry, average gradation, published for estimating purposes and subject to ±33%. | The base course order grows about 17%: the default 20 by 12 ft slab on a 4 in base goes from 3.5 to 4.0 cu yd of loose gravel (2.96 cu yd compacted). Concrete volume, bag counts, truck loads and cost are unchanged. |
| 2026-09-19 | C-103 Sand Calculator | The bank column was offered as a stand-in for compacted sand, in a warning, an assumption and a section of the page: bank is Caterpillar's undisturbed-deposit WEIGHT, and no compaction conversion was available on the sheet. | Bank is presented as a weight column and nothing else, and a new advanced toggle, “Depth is the compacted layer”, orders 1.25 loose cubic yards per compacted cubic yard (formula rev. 1.1.0): FHWA Exhibit 5.1 A, sand dry, 3,240 over 2,590 lb/cu yd, published for estimating purposes and subject to ±33%. It is ignored on the bank column. | No default result changes: the toggle ships off and the bedding preset is a screeded depth, not a compacted one. Ticked, the volume, tonnage and bag count ordered grow 25%. |
| 2026-09-19 | C-101 Gravel Calculator | A compacted depth was converted with Caterpillar's 0.89 bank-to-loose load factor used as a compaction stand-in (loose = placed / 0.89, about +12%): that factor is the ratio between undisturbed and loose material, and the table publishes no compacted column. | The conversion is the labelled FHWA Exhibit 5.1 A ratio carried by each material row (formula rev. 1.1.0): 1.31 for the gravel rows, 3,570 embankment over 2,730 loose lb/cu yd, 1.25 for sand, published for estimating purposes and subject to ±33%. Materials with no row in that table — crushed stone, the supplier blends, topsoil, loam — are ordered as measured unless you type a compaction allowance, which then wins for any material and is printed as your own. | The compacted toggle is on by default, so the default 20 by 12 ft, 4 in sheet (2.96 cu yd in place) goes from 3.5 to 4.0 cu yd ordered, a loose volume 16.6% larger, with the tonnage, loads and cost that follow. |
| 2026-10-12 | S-101 Concrete Calculator and G-201 Concrete Cost Calculator | The line labelled Concrete volume showed the volume with the waste allowance added, while the same label on the S-103 Footing Calculator showed the net volume: a 10 by 10 ft, 4 in slab at 10% waste read 1.36 cu yd next to a takeoff sheet showing 1.23 net. | Concrete volume is the net volume on every sheet. The waste allowance is carried by the Order quantity, the bag count, the truck loads and the weight. On the cost sheet, the Concrete volume line replaces the separate Net volume line. | The Concrete volume line now shows the net volume: 1.23 cu yd instead of 1.36 for the 10 by 10 ft, 4 in slab at 10% waste. The order quantity (1.5 cu yd), bag counts and cost are unchanged. |
| 2026-10-12 | M-101 Duct Calculator | The default roughness, 0.0003 ft (0.09 mm), was credited to "Chen et al., 2012" as the value ASHRAE gives for galvanized steel, with no mention that the paper reports it for duct fittings. | The paper is credited to its three authors, Liu, Long and Chen (2012). The sheet states that 0.09 mm is the roughness ASHRAE supplied for the galvanized fittings in that study, that the paper gives no straight-duct value, and that applying it to straight duct is the sheet's assumption. | No number changes: the default roughness, the friction rate and the duct sizes are the same. Only the attribution and the stated scope of the default are corrected. |
| 2026-10-15 | C-101 Gravel Calculator | The supplier yard-chart weight of 2,700 lb per cubic yard for sand, gravel, decomposed granite, rock and river cobble linked to the North Bay Materials density page, which stopped answering when the supplier became Terra Bay Materials (the old address now redirects to a missing page). | The source now links to the Internet Archive copy of the same page, captured on 17 May 2026, where the same row and the same supplier note can still be read. | No number changes: the weights, tons and loads on the sheet are the same. Only the source link is replaced so the cited figure can still be checked. |
Current formula revisions
| Sheet | Tool | Formula rev. | Revised |
|---|---|---|---|
| S-101 | Concrete Calculator | 1.3.0 | 2026-10-01 |
| S-102 | Rebar Calculator | 1.0.0 | 2026-09-19 |
| S-103 | Footing Calculator | 1.0.0 | 2026-09-21 |
| G-201 | Concrete Cost Calculator | 1.1.0 | 2026-10-01 |
| C-101 | Gravel Calculator | 1.1.0 | 2026-09-19 |
| C-201 | Asphalt Calculator | 1.0.0 | 2026-09-19 |
| C-102 | Fill Dirt Calculator | 1.0.0 | 2026-09-20 |
| C-103 | Sand Calculator | 1.1.0 | 2026-09-19 |
| C-105 | Topsoil Calculator | 1.0.0 | 2026-09-20 |
| A-201 | Concrete Block Calculator | 1.0.0 | 2026-09-19 |
| A-203 | Paver Base Calculator | 1.0.0 | 2026-09-20 |
| A-102 | Roofing Calculator | 1.0.0 | 2026-09-19 |
| A-104 | Roof Pitch Calculator | 1.0.0 | 2026-09-20 |
| S-202 | Wall Framing Calculator | 1.0.0 | 2026-09-19 |
| S-203 | Rafter Calculator | 1.0.0 | 2026-09-21 |
| S-201 | Board Foot Calculator | 1.0.0 | 2026-09-20 |
| A-301 | Deck Calculator | 1.0.0 | 2026-09-19 |
| A-302 | Fence Calculator | 1.0.0 | 2026-09-21 |
| A-202 | Mortar Calculator | 1.0.0 | 2026-09-21 |
| S-301 | Stair Stringer Calculator | 1.0.0 | 2026-09-20 |
| G-101 | Cubic Yard Calculator | 1.0.0 | 2026-09-26 |
| G-102 | Square Footage Calculator | 1.0.0 | 2026-10-13 |
| M-101 | Duct Calculator | 1.0.0 | 2026-09-26 |
| P-101 | Pipe Weight Calculator | 1.0.0 | 2026-09-26 |
| A-303 | Chain Link Fence Calculator | 1.0.0 | 2026-10-15 |
| C-106 | Tonnage Calculator | 1.0.0 | 2026-10-19 |
What counts as a correction
- A formula that produced a wrong quantity.
- A reference value that was wrong or misattributed, such as a bag yield or a unit weight.
- An assumption that was applied but not disclosed.
- A statement of practice that was wrong or presented as a code requirement.
Typos, wording and layout fixes are not corrections and are not logged. They also do not bump the formula revision in a title block.
How a correction is handled
- The failing case is turned into a test that reproduces the wrong number.
- The formula is fixed until the test passes and every existing test still passes.
- The formula revision in the sheet title block is bumped and the revision date changes.
- The change is written into the log above, including what the old number was.
Reporting one
The most useful report contains the inputs you entered, the number the sheet gave you, the number you believe is right, and how you arrived at it. A source helps but is not required; "my plant bills in half yards, not quarter yards" is a perfectly good report. Send it to contact@takeoffmetric.com.