What the calculator knows, and what it does not
The form reads length, height, board width and gap, spacing, gates and optional concrete and price inputs. It has no field for an existing board count, damaged boards, reusable rails or posts that remain in place. Choosing either wood type does not turn on a repair mode.
That distinction is about inputs, not a judgement about the condition of your fence. The calculator cannot decide whether an existing component can be retained or what additional work a repair requires. Its single-run scope remains the same.
A full-run result is not a damaged-item count
A hypothetical software check used 100 ft total length, 6 ft height, 8 ft post spacing, 6 in boards, zero gap and no gates. The actual submit handler returned 200 pickets, 14 posts, 39 rails and 1200 fasteners. The picket equation was ceil(100 × 12 / 6) = 200. No existing materials or damage records were entered.
Now suppose a separately counted, hypothetical inventory also contains 200 boards. The matching total is an explicit assumption for this example, not a survey performed by the tool. Two different repair records could divide that inventory as follows:
| Record | Existing boards counted | Boards retained | Boards removed | Defined one-for-one replacements |
|---|---|---|---|---|
| A | 200 | 190 | 10 | 10 |
| B | 200 | 180 | 20 | 20 |
The inventory checks are 190 + 10 = 200 and 180 + 20 = 200. Replacement equals removal only because these examples explicitly define one new board per removed board, with no redesign or additional allowance. That is not a general repair rule. A real record must describe its actual scope.
The same full-run calculator inputs would still return 200 pickets for both records. There is no repair-record input that could make it distinguish ten replacements from twenty.
Why shortening the run is not a repair mode
You might try entering just enough length to make the board result equal a chosen replacement count. In another actual-handler check, a hypothetical 5 ft run with the same height, spacing, board width and zero gap returned ceil(5 × 12 / 6) = 10 pickets.
But its other cards still described a new short run: 2 posts, 3 rails and 60 fasteners. It did not infer that existing posts or rails would be kept. Changing that short run's post spacing from 8 ft to 4 ft kept the picket count at 10 while returning 3 posts and 6 rails. Those are software outputs, not extra repair items to purchase.
The shortcut changes the modeled length; it does not add a retained-materials inventory. A convenient picket number is therefore not evidence that the rest of the result represents your repair.
Build a separate replacement record
- Identify the item: record the actual component, size and location rather than a generic total for the whole run.
- Separate retained and removed items: state the basis for keeping or replacing each component; do not let the calculator decide its condition.
- Record the replacement scope: distinguish a one-for-one replacement from a changed layout or different material system.
- Keep connections separate: document required fittings and fasteners for the actual work instead of copying the new-run allowance.
- Leave unknowns visible: an unassessed rail, post or connection is unknown, not automatically reusable and not automatically a zero-quantity replacement.
This is a recordkeeping checklist, not a condition assessment, repair procedure or supplied parts list. The calculator's optional cost also prices its modeled quantities, not this separate replacement record. No repair labour or disposal estimate is produced.
Method and source
The supported fields and actual counts come from this site's form and calculation code. The full-run check and two short-run controls were executed against the unchanged handler. The two inventory records are independently constructed hypothetical arithmetic. No material prices, manufacturers, real-property measurements or installation requirements were assumed.
For the implemented formulas, see how pickets are counted and how posts are counted. Keep those planning results separate from an assessed repair inventory.