Vaulted ceilings — cathedral, single-slope, and pyramid

Step by step

1. 1

   Pick the Vaulted Ceiling tool

   In the Build Panel (on phones, the Walls, Doors & Windows sheet), tap the Vaulted Ceiling tile. The canvas enters draw mode with a Drag a rectangle over the vaulted area prompt across the top.

   

2. 2

   Drag a rectangle over the area

   Drag a rectangle across the part of the room that vaults — roughly is fine, it snaps to your walls. Let go and the vault drops in as a two-slope Cathedral by default, with its inspector open along the bottom.

   

3. 3

   Choose Cathedral, Angled, or Pyramid

   In the inspector along the bottom, tap the type chip to cycle Cathedral → Angled → Pyramid. Cathedral is two slopes meeting at a ridge; Angled is a single slope from a low Eave up to a High edge; Pyramid is four slopes rising to an Apex (or to a flat square top — see below). Width and Depth fine-tune the footprint at any time.

4. 4

   Set the eave and the peak

   Set the Eave (the low side, where the ceiling meets the wall) and the peak: Ridge on a cathedral, High edge on an angled ceiling, or Apex on a pyramid. On a cathedral, the two slope runs are Slope 1 and Slope 2 — type an exact run for either (or drag the ridge line on the canvas) to make one slope longer than the other for an off-centre ridge. On an angled ceiling, Flip slope swaps which side is high.

5. 5

   Give a pyramid a flat top (optional)

   A pyramid rises to a point by default. Set the Top field to the side length of a flat square top — a small landing where a skylight, a cupola, or a flat panel sits instead of a sharp apex. Leave Top at 0 for a true point.

   

6. 6

   Close the gaps: Fit to walls

   If the vault's sloped edges stop just short of the walls, they leave a gap where the roof should rest — visible as a thin curb in 3D. Tap Fit to walls and the vault's nearby edges snap onto the walls to close those gaps exactly. The 2D outline flashes a solid green as it locks; while any gap remains it shows an orange warning outline, and Flow Check flags it too. Fit to floor plan is the bigger hammer — it spans the vault across the whole plan so every sloped edge meets a wall.

   

7. 7

   See it rise in 3D

   Switch to the 3D view. The ceiling rises to its ridge or apex, the walls and any pillars underneath take their real sloped shape (chopped off cleanly along the roofline, not poking through it), and any ceiling fan or chandelier hangs from the actual sloped ceiling — not a phantom flat one. Elevation views and every export (PDF, image, CAD) show the vault too.

   

8. 8

   Drop the eave to the floor for an attic

   Set the Eave to 0 and the low side of the roof meets the floor — the true attic room where a knee wall would otherwise stand. Use Fit to walls (or Fit to floor plan) first so the sloped edges land exactly on the wall line; then in 3D the roof runs straight down to the floor with no leftover stub of wall. The slopes come down onto the two walls that run parallel to the dashed ridge line; the other two walls become the gable ends and rise to the peak. Flow Check keeps watching the low side so you know what actually fits under it.

   

9. 9

   Walk in to check the shape

   Open the 3D view and tap Walk through (the footsteps button, bottom right), then turn to face one of the gable ends. With Eave 0 you see the classic A-frame: two slopes meeting at a sharp peak, and a triangular end wall. In the walk-through the ceiling is always shown; in the normal 3D view, tick Ceiling to see it.

   

10. 10

    Flat strip at the top instead of a peak? Add a soffit across the vault

    Many real attics have a flat ceiling across the top, where collar ties carry a flat panel, so the cross-section looks like a peak with its tip cut off. You build it with two pieces: the cathedral vault you already have (Eave 0, Ridge at the height the slopes would meet) plus a soffit that supplies the flat part. In the Build Panel (on phones, the Walls, Doors & Windows sheet) tap Soffit / Bulkhead and drag a rectangle over the whole vaulted area, wall to wall. Under a vault the soffit's inspector gets an extra field, Underside: the height of the flat ceiling above the floor. Type it, for example 8′. The soffit fills the space from that height up to the roof, so wherever the roof is higher than 8′ the room gets a flat ceiling at 8′, and below that the slopes carry on down to the floor. How wide the flat strip comes out depends on the heights: strip width = room width across the slopes × (1 − Underside ÷ Ridge). In a 16′ room with a 12′ ridge, a flat ceiling at 8′ is 16 × (1 − 8/12) ≈ 5′4″ wide. To get a set width, work back to the ridge: Ridge = Underside × room width ÷ (room width − strip width). For example, a 4′ strip at 7′6″ in a 16′ room needs a 10′ ridge. The Underside can be at most 8′ below the top of the roof.

    

11. 11

    Walk in again: slopes to the floor, flat across the top

    Back in the walk-through, the gable end is now a peak with its top cut off: the two slopes still run down to the floor, and a flat ceiling spans the top. Change the soffit's Underside to raise or lower the flat part (a lower flat ceiling makes the strip wider). Because the flat part is a separate soffit, you select it on the plan like any soffit (where it overlaps the vault, a small menu lets you pick Soffit or Vaulted ceiling). To go back to a sharp peak, delete the soffit.

    

12. 12

    Add exposed beams (optional)

    Exposed beams are the timber you see in a barn or loft room: rafters running down each slope, a ridge beam along the peak, and collar ties or rafter ties across the room. They're available on Cathedral vaults. Select the vault, open the Beams tab in its inspector, and tap Add beams. The vault itself is already a solid, closed ceiling. Beams sit underneath it as decoration, so there's no need to fill in anything between them.

    

13. 13

    Lay out the beams: Auto or Manual

    Beam settings are split into three tabs. On Layout, Include picks which kinds of beam you want (Rafters, Ridge, Collar ties, Rafter ties). Placement chooses how they're placed: Auto spaces everything evenly. Set the number of Rafters or the Rafter spacing (either one updates the other), the number of ties, and the tie height, either as Collar height above the floor or as Collar length. They're the same setting: a higher tie is a shorter one. You can't have more ties than rafter pairs. Manual starts from the current auto layout and lets you place each beam yourself: + Rafters, + Collar ties and + Rafter ties add one, you drag a rafter to move it and its ties come with it, and you drag either end of a tie to raise or lower it (it stays joined to both rafters). Select a beam and press Delete to remove it. Switching back to Auto clears your manual changes. Selected shows the beam you tapped (on the plan or in its list): its Length, Height for a tie, From end for a rafter, and Delete. Style has Beam W and Beam H (the size of every beam), Finish (Natural pine, Oak, Walnut, Dark stain, Whitewash, Reclaimed), Reset, which puts the beams back to evenly spaced and undoes manual moves and deletes, and Remove, which takes all the beams off this vault.

    

14. 14

    Beams with gaps between them in 3D? Turn on Ceiling

    The 3D view opens with the ceiling hidden so you can look into rooms from above. With beams on a vault, that means you see the rafters with open sky between them. Nothing is missing: tick Ceiling at the bottom right of the 3D view and the solid sloped ceiling is back. From outside it covers the beams, so walk through to see them from below.

    

15. 15

    See the beams under the ceiling

    Tap Walk through and look up: the rafters run down each slope, the ridge beam runs along the peak and the collar tie spans between the rafters, all set just under the solid ceiling.

    

16. 16

    Can't select a wall under the vault? Close the vault first

    If tapping an interior wall under a vault does nothing, or the plan seems frozen, the vault is probably still selected. You can tell because its inspector is open along the bottom and its corners show round handles. While a vault is selected, it takes every tap and drag inside its outline: dragging moves the whole vault, and a tap just closes it, so the wall you tapped doesn't respond and the plan shifts as the inspector closes. Tap the X on the vault's inspector (or press Esc), then tap the wall itself, right on the wall line. A tap on an empty spot inside the vault selects the vault again, so aim for the wall. If you dragged the vault by mistake, Undo puts it back.

    

17. 17

    Still in the way? Hide vaulted ceilings in Layers

    If a vault covers the whole plan, it's easier to switch it off while you work on what's underneath: walls, doors, furniture. Tap the Layers button (the stacked-sheets icon in the toolbar above the plan) and untick Show vaulted ceilings. The vault's outline, ridge line and slope arrows disappear from the 2D plan and can't be selected, so everything under them responds normally. Skylight markings are hidden from the 2D plan too. Nothing is deleted. The vault is still there in 3D, in elevation views and in every export. The setting is remembered on this device, so tick it again when you want to edit the vault (choosing the Vaulted Ceiling or Skylight tool turns it back on automatically).

    

18. 18

    Edit the wall: the vault is still there

    Now tap the wall and its inspector opens as usual: drag the crosshairs, type a Length, change the Style, or delete it. Where the height field would be, it reads Follows the vaulted ceiling, which tells you the vault is still in place and the wall still meets the slope in 3D.

    

Common mistakes

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