Modelling in 3D is the most powerful and reliable way to estimate roofing, primarily because it affords the opportunity to check that you are correct. The checking process is important and if applied to every job, it will highlight errors at an early stage.
At AppliCad, we do NOT consider this an option – it is compulsory.
🔧 Model checking tools
🧾 Essential checking steps
Close Square - Check last two dimensions against your plan/sketch (usually the most appropriate way to close out the wall/eave outline).
This is not used if you import the 3D model via RXF or XML.
View > Four Views - This allows you to check the model geometry from four standard points of view. You should also change to an ISO view and spin it, especially on complex models. If it doesn't look right, it probably has something wrong with it and deserves closer scrutiny.
Tools > Show/hide planes - If all the planes are present, then roofing material will be applied.
Tools > Show/hide line types - The line type determines the flashing and trim material that will be applied to the roof edges. The actual material is not applied to the line until Cover stage. If a line needs to be changed, use the Change Line Type function – eg Fascia to Box Gutter.
Simply click the button again to turn them off.
Tools > Auto-Insert Dimension - Applies dimensions to the overall perimeter. This includes eave overhang if applied. Compare with drawings/sketches supplied.
Tools > Insert Roof Line Lengths - Inserts the actual length of each line, up the slope of the roof. The appearance of line dimensions can be set to match the line colour and the distance off the line set in your Preferences.
Tools > Insert Line/Line Dimension - This allows you to insert a dimension between parallel lines, typically ridge to eave. It inserts a dimension that is the rafter length and approximate sheet length for a metal panel roof.
You can also insert a dimension from the eave line to the apex of a hip end. Select the eave line first (d1) as this sets the position for the dimension. Then select the ridge line (d2).
The reminder message is displayed, giving you the option to accept the dimension, in case you selected lines in error.
Tools > Insert Point/Point Dimension - In this case, you first locate the two points you wish to dimension, usually by ‘snapping’ to an existing point using the middle mouse button at (d1) and (d2), followed by the position for the dimension (d3) left mouse button.
Tools > Show Pitch - Inserts the pitch of the roof, and if set in your preferences, will also display the roof storey (individual roof level within a multi-level structure) and the slope direction.
Tools > Check Model - This function automatically checks for corrupt or damaged roof geometry. This is especially important for jobs imported or models that you have spent a lot of time 'adjusting'.
If the job passes the Model Integrity test, the message is displayed in the Prompt area. Corrupt records will be deleted automatically, thus 'cleaning' the model. You may have to put some lines and planes back in using Smartlines.
Tools > Tally Quantities - Displays the geometric quantities and lengths for the entire roof and all roof features. It includes volume of the attic space and the length of each line type by storey and total. You can also verify each of the line type groups to confirm that you have the correct line type assigned. Select the […] button and the selected line types will flash on screen. Check that they are the correct lines.
⚠️ Important reminder
These steps are not an option and will help you get the correct result every time. Remember to check your job. If the model is correct, the take-off will be correct. The accuracy of the final result is a measure of your success.