Slopes and tapered wedges

Before you start

Slope design creates wedges of thermal insulation so that water flows to the outlets. The following must be finished in the roof editor:

• the scale and the roof outline,
• at least one outlet: Drain, Gutter (gutter or free drainage edge) or Scupper. Each separate part of the roof needs its own outlet.

Neither the build-up nor the materials are needed to calculate the wedges. If something is missing, the slope editor does not start the calculation and tells you what to add.

Slope design is for a flat roof with a level supporting structure. A hall with a sloped deck has no wedges; it is described in the guide Hall and diverters.

1. Open the slope design

1. In the project cockpit, open the Calculations tab.
2. In the Slope design and crickets section, click Open slope design. The editor opens for the active roof.
3. The editor has two steps: 1. Slopes and 2. Crickets. The second step is unlocked after the first calculation.

2. Parameters

• Slope: the slope of the wedges in percent.
• Grid module: the wedge grid, 1 m or 0.5 m.
• Initial thickness of wedge A: the thin edge of the first wedge A at the drain, at least 20 mm. The drain square has no wedge and the drain lies on the base insulation. Wedges A, B, C … are laid from it, each one following on from the previous one. Below the field you can see the series of wedge thicknesses at the slope entered.
• Base insulation is shown above the field, read-only. You enter it in the roof editor in the Steps window or in the Materials tab.

The application calculates a slope of less than 3 %, but warns you about it.

3. Wedge mode

• Standard: tapered wedges only, without substrate boards.
• Repeating: fewer wedge types (the Number of wedge types option); flat substrate boards make up the missing height. The boards are in the schedule, and the total insulation volume stays the same.
• Complementary wedges for valleys and hips: a valley or hip cell gets one complementary wedge instead of two cut ones. It is listed in the schedule as an additional item.

4. Grid

• You set Grid rotation as a number, with the − and + buttons in half-degree steps, or with the Auto button. When the roof has a free drainage edge, the grid is aligned to it and manual rotation is not offered.
• Grid tools: Corner (click a roof corner and a grid intersection passes through it), Edge (the grid rotates parallel to the edge) and Move (by dragging on the canvas).
• If the outline changes later, the editor tells you that the alignment is no longer valid. Align the grid again.

5. Generate slopes

1. Click Generate slopes. The calculation may take a while; the editor loads the result by itself.
2. The Slope wedges / Tech. drawing switch changes the view of the plan. Wedge labels shows the wedge types.
3. The Slope findings card warns you, for example, about a strip without fall from which water cannot drain. The Show button highlights the spot on the canvas.
4. The card also shows the status of the design: Ready for construction or Draft to be completed – not ready for construction with the findings of the piece check. A draft to be completed also carries a warning in the outputs.

If the geometry changes during the calculation, the calculation is not completed and the editor asks you to run it again. A result for the old outline would not be valid for the new one.

6. Crickets at obstacles

• Crickets at obstacles (skylight, chimney, shaft, superstructure …) are not drawn. They are created during the slope calculation as a layer of flat EPS boards on the wedges and lead water around the obstacle.
• The 2. Crickets step is an overview: crickets with the marks R1, R2 …, board counts and warnings. They are orange on the slope plan.
• If the calculation has no crickets, the step says so. Water flow around the obstacles is then resolved in the tapered wedges.

7. Results and outputs

• The Results tab, after clicking Show detailed outputs, the Thermal insulation card: wedges by type, Ordering volume (whole boards) and substrate boards.
• In the same tab, under Production documents, you download Cut list and order (CSV) and Substrate board plan (PNG). The 3D visual check of the slope design link shows the roof in 3D.
• The Protocols tab: the chapters Wedge plan, Wedge schedule and Volume list, and under Documents for suppliers the Thermal insulation and slope wedges card. The Site drawing is created from a released revision of the supplier document.

Narrow perimeter cuts at the parapet are usually filled in on site from leftovers. In the Materials tab, section Slope wedges: ordering, there is the field Do not order cuts narrower than. The schedule then lists them on a separate row.

When to recalculate

• After a change to the outline, openings or outlets, the slope design result is no longer valid. Open the slope design and click Generate slopes again.
• A new slope calculation invalidates the Anchor plan and the Green roof, because they are based on the wedge heights. Run them again afterwards.