Model one supported section at a time
Each row represents a compatible planar section with a measured horizontal plan area and rise-per-12 pitch. The workbench applies the corresponding multiplier, shows the sloping subtotal and adds the rows.
Names such as Main gable, Rear shed and Porch make the record checkable. Duplicate only when the geometry is genuinely the same; otherwise add a new section.
Local save, print and export
Save stores the job label and measurements only in this browser. Clear saved data from the same controls. Export creates a plain JSON record containing the job, timestamp, inputs, formulas, results and safety boundary; it contains no account or personal details.
Printing removes navigation and preserves the calculation record. A downloaded record should be handled like any project document because measurements can still be commercially sensitive.
Complex roofs and limits
Up to 100 sections are supported. The workbench does not infer missing geometry or invent areas for hips, valleys, dormers, intersections or curved surfaces.
These calculations describe geometry only. They do not size rafters or trusses, assess loads, approve a design, interpret building codes, specify cuts or fasteners, or guarantee material quantities.
Roof work can cause serious injury. Do not climb onto a roof merely to collect inputs. Prefer drawings, ground-level measurements, accessible interior information or dimensions supplied by a competent professional.
Inputs, units and calculation stages
A job uses one common area unit so sections cannot be silently mixed. Each section needs a unique descriptive name, a horizontal plan area and rise per 12. The record shows the multiplier, status and sloping subtotal before save or export.
Divide only known geometry into supported simple planes, enter each plan area and pitch, inspect every subtotal, reconcile total plan area with the source drawing, then save, print or export. Invalid rows remain visible but are excluded from the sloping total.
Worked examples
Main roof: 100.00 m² at 6/12 uses factor 1.118034 and contributes 111.80 m². Porch: 12.00 m² at 3/12 uses factor 1.030776 and contributes 12.37 m². Their combined sloping area is 124.17 m².
For an imperial record, a 900 ft² rear section at 4/12 contributes 948.68 ft² and a 300 ft² entry canopy at 2/12 contributes 304.14 ft². Names, units and section formulas travel with both exports.
Errors, limits and responsible use
The 100-section cap prevents an accidental unbounded interface. It is not evidence that a complex roof can be reduced safely to 100 rectangles. Overlaps, missing surfaces, valleys, hips and dormers must be resolved from reliable geometry before entry.
Check the source measurements, selected unit, representation and displayed assumptions before consequential use. RoofFigured explains geometry only; it does not provide structural design, code approval, installation instructions or a guaranteed material order.
Frequently asked questions
- Are invalid rows included in totals?
- No. Their status is visible and the record counts valid and excluded sections.
- Can sections use mixed units?
- No. One common area unit is selected; changing it converts all section areas together.
- Where is a saved job stored?
- Only in this browser local storage until cleared. It is not uploaded.
- What does JSON add over CSV?
- JSON retains version, method, timestamp and boundary in a structured record; CSV supports a straightforward table.
- Can I recover a deleted section?
- Yes. Undo restores the last deleted populated section during the current visit.
Continue the calculation
Sectioning guide provides the next explanation; Complexity boundary
Build a plane schedule that another person can audit
Create one row for each reliable, non-overlapping horizontal projection. Give it a name that matches the drawing, choose direct area or rectangular dimensions deliberately, and assign the pitch for that plane. Review the displayed factor and subtotal before adding another section. Duplicate only when the source really contains a repeated plane, then rename it so two counted rows cannot be confused.
First reconcile the sum of horizontal plan areas with independent source information. Then review the sloping total. Invalid rows are shown and excluded; they should be corrected or documented, not ignored simply because the remaining total looks plausible. The workbench supports up to one hundred sections for record handling, but a large row count is not evidence that complex roof geometry has been measured correctly.
Use local storage and export deliberately
Save locally stores the job label, unit and sections in the current browser. It creates no account, cloud backup or collaboration record. Clear saved data through the visible control when the browser should no longer retain it. Because job labels and measurements may still be commercially sensitive, avoid personal or confidential information and use an appropriate device and browser profile.
JSON preserves structured fields, raw values, methods, calculation version, timestamp and boundary text. CSV provides a spreadsheet-friendly table, while Print creates a readable record that can be saved as PDF by the browser. Compare the valid sections and totals across formats. Retain the source drawing revision with the export and regenerate the file after input changes instead of editing only the final number.
Know when the workbench must stop
The workbench aggregates supplied simple geometry; it does not discover hip, valley, dormer, intersection or curved-surface boundaries. Do not invent rectangles or average pitches to fill a schedule. Where a plane cannot be established from reliable accessible information, mark it outside the result and obtain a competent measured takeoff. Preserve exclusions in the exported record so the total is not mistaken for a complete roof.
Totals describe ideal geometry only. Structural design, code compliance, cutting, fastening, drainage, product suitability, coverage, waste and ordering remain separate decisions. Do not access a roof merely to populate a row. Use drawings, ground-based measurements, accessible interior information or a competent professional, and independently verify consequential results before use.