⚠️ Important: This method is deprecated and has been superseded by the Block-Cut method, which provides greater flexibility and better results for most roof shapes. Generate Offcuts is now only available via pulldown menu.
🧾 What Generate Offcuts does
The Generate Offcuts method optimises material usage by taking triangular offcuts created from hips and valleys and placing them elsewhere on the roof. This reduces wastage by effectively 'flip-flopping' triangles of material rather than using rectangular blocks.
This method only works with certain profiles that can be split and flipped. It is not practical for profiles such as standing seam. Generate Offcuts is best suited to simpler roof shapes only.
🔧 How to use Generate Offcuts
When you select Generate Offcuts as your estimation method, you'll see a dialog box with three optimisation options:
Do you want to Merge Jack-End Sub-Blocks?
NO: Will not review the placement of Jack-End Sub-Blocks
YES: The software examines each Jack-End Sub-Block (triangle shaped block bounded by a hip and valley) and determines whether that block can be matched with an adjacent triangle in the same roof plane
Do you want to Modify the Length of Straight Blocks (Half)?
NO: Will not reduce the number of panels/sheets in a block
YES: Calculates the total eave length defining the block and divides by panel width. Uses the smaller number of panels if less than the original calculation. Only works when Rounding is turned on
💡 This function looks across the width of a run of eave (for example, combined width of Block 1 and Block 2) and compares the total panels needed versus individual block calculations. If Block 1 needs 6.6 panels and Block 2 needs 5.3 panels, individual rounding gives 13 panels total (7+6). Rounding the whole run gives 12 panels (7+5), where Block 1's oversupply covers Block 2's undersupply.
Do you want to round the sheets in each block?
NO: Treats each block separately and only rounds after grouping. Example: 3.6 @ 3000 + 2.2 @ 3000 = 5.8, rounded to 6 sheets @ 3000mm. Gives smallest number but no margin for error
YES: Rounds each block before grouping. Example: 3.6 @ 3000 rounds to 4, 2.2 @ 3000 rounds to 3, total = 7 sheets @ 3000mm. More efficient with spare panels for site errors
Click OK to begin the offcuts process.
🔧 Nesting options
After generating offcuts, you'll see another dialog for handling short sheets and waste reduction:
Option | Description |
Maximum sheet length | Determines sequence order. Reducing length increases waste. Pieces longer than maximum are not modified. Default is the profile's associated length. Enter 0 to ignore maximum length |
Nesting of narrow pieces | Choose to combine narrow pieces into nesting or ignore them and add to end of coil |
Detailing of narrow pieces | If adding narrow pieces to sequence end, choose collective or individual annotation |
Do you want to Turn Remaining Sub-Blocks into Strips?
NO: Will not divide sub-blocks into individual sheets. Describes area as number of sheets to cover without nesting optimisation
YES: Areas that cannot be divided into triangular offcut blocks are further divided into individual panels that are nested using linear nesting algorithm to reduce waste
🧾 Understanding the results
Generated sheets are categorised as:
Category | Description |
C/O | Cut sheet and related offcut, grouped by colour - matched triangles of roof areas |
S | Straight sheet areas - rectangular blocks/areas |
Sht | Single sheets, individual or nested sheets |
The process shows sheet placement on the offcut layout drawing and provides a detailed cutting list.
📊 Generated reports
Two main drawings are generated under Reporting > Drawings:
Off-cut Layout: Shows sheet placement on the roof
Panel Cutting Details: Shows individual sheets in nested groups
Reports include:
Top table: Summary of individual sheets (may be nested) required for the job
Bottom table: Summary of Cut/Off-cuts and Straight sheets/blocks
💡 The system can reduce waste significantly - examples show reductions from 12.4% to 8.3%, with some jobs achieving 10-12% savings depending on roof shape and number of cuts.