Vaulted ceilings — cathedral, single-slope, and pyramid
Draw a vaulted ceiling over any part of a room — a two-slope cathedral, a single-slope shed, or a four-sided pyramid — set the eave and ridge heights, and the room, its walls, its pillars, and its hanging lights all take the real sloped shape in 3D. Drop the eave to the floor and you have a true attic room.
Not every room has a flat ceiling. A vaulted ceiling rises with the roofline — a Cathedral with two slopes meeting at a ridge down the middle, an Angled ceiling with a single slope climbing from a low eave to a high edge, or a Pyramid with four slopes rising to an apex (or to a flat square top). In RoomSketch3D you draw one over any part of a room and it becomes a real sloped volume: the walls and pillars beneath take their true tapered shape, and it shows up in 3D, in elevation views, and in every export.
You draw a vault the way you'd sketch it — drag a rectangle over the area. It doesn't have to be exact: the rectangle snaps to your walls. Then you set the heights and shape the slopes in the inspector — and if the eave drops all the way to the floor, you get a genuine attic room where the roof meets the ground.
What you'll need
- •A room with walls (any design works)
- •About five minutes
Step by step
- 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.
The Vaulted Ceiling tool armed — the canvas is waiting for you to drag out the area. - 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.
Drag out the area — it snaps to the walls — and the inspector opens with the vault's controls. - 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
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
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.
Pyramid type adds an Apex height and a Top field — the side length of the flat square top (0 = a point). - 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.
Fit to walls snaps the nearby edges onto the walls; the outline flashes green on a clean lock. - 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.
In 3D the ceiling rises to the ridge and the walls beneath follow the real slope. - 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 first so the sloped edge lands exactly on the wall line; then in 3D the roof runs straight down to the floor with no leftover stub of wall. Flow Check keeps watching the low side so you know what actually fits under it.
- 9
Hide the markings while you furnish
The vault draws its ridge and slope lines on the 2D plan. When they get in the way of arranging furniture, open the Layers button (formerly Labels) and flip Show vaulted ceilings off — the vault stays, its markings just step out of the way.
Tips
Tall pieces? Flow Check watches the low side
The eave side is where headroom runs out. Smart Flow Check warns when a tall piece — a wardrobe, a bookcase, a fridge — won't clear the low side of the vault ("won't fit under the sloped ceiling"), so you catch the clash before you build. Move the piece toward the ridge, where the ceiling is higher, to clear it.
Interior walls and pillars taper too
A wall or a load-bearing pillar that stands under the vault is sliced to the roofline in 3D instead of punching through it. On the 2D plan it's drawn with a dashed outline and a small chevron pointing downhill, and its inspector shows Follows the vaulted ceiling where the height field would be.
A door or window can be too tall for the slope
Under a sloped ceiling a tall door or window can run past the roof at that spot. Flow Check flags it — "a door or window is taller than the ceiling here" — so lower its height or mount, or move it toward the ridge where the ceiling is higher.
Off-centre the ridge on purpose
A ridge doesn't have to sit in the middle. Give Slope 1 and Slope 2 different runs (or drag the ridge line) for the asymmetric look of a room tucked under one side of a roof.
Roughly is fine — it snaps
Don't fuss over the drag. The rectangle snaps to your walls, and Fit to walls cleans up any leftover gap in one tap — so a quick sweep over the area lands the vault where the roof really sits.
Common mistakes
A thin stub of wall left under the roof
If the vault's sloped edge stops short of the wall, 3D shows a small curb or stub between roof and wall — and with the eave at 0 you'll still see a low wall you didn't want. That's a gap, not a bug: tap Fit to walls to snap the edge onto the wall and it closes cleanly.
Drawing a vault you can't see
Picking the tool automatically un-hides the ceiling layer, so a fresh vault always shows. If an older vault seems missing, check the Layers menu — Show vaulted ceilings may be off from an earlier furniture pass.
Expecting the slope in the flat 2D plan
The top-down plan shows the ridge and slope lines, but the rise itself reads in the 3D view and in elevation views — that's where a too-low eave or a wrong ridge height jumps out.
Frequently asked questions
What's the difference between Cathedral, Angled, and Pyramid?
A Cathedral ceiling has two slopes that meet at a ridge, like the classic peak down the middle of a room. An Angled ceiling is a single slope that climbs from a low eave to a high edge — a shed or lean-to ceiling. A Pyramid has four slopes rising to a central apex (or to a flat square top). Cycle between them with the type chip in the inspector.
Can a pyramid ceiling have a flat top instead of a point?
Yes. Set the Top field to the side length of the flat square top — useful for a skylight, a cupola opening, or a flat panel at the peak. Leave Top at 0 for a true point apex.
How do I make the ceiling meet the floor for an attic room?
Set the Eave to 0. The low side of the roof then runs all the way down to the floor — the attic look where the roof replaces a knee wall. Use Fit to walls first so the sloped edge lands exactly on the wall, or you may see a thin stub of wall left behind.
The 3D view shows a low wall under my roof — how do I close it?
That's a gap between the vault's sloped edge and the wall. Select the vault and tap Fit to walls: its nearby edges snap onto the walls and the gap closes. While a gap remains the 2D outline shows orange and Flow Check flags it; it flashes green when it locks. Fit to floor plan spans the vault across the whole plan if you want every edge to meet a wall at once.
Do interior walls and pillars follow the slope?
Yes. Any interior wall or pillar under the vault is chopped to the roofline in 3D rather than poking through it, drawn with a dashed outline and a downhill arrow on the 2D plan, and its inspector shows Follows the vaulted ceiling in place of a fixed height.
Does the vault work on a rotated or traced floor plan?
Yes. It aligns square to a rotated plan, Rotate 90° snaps it to the room, and you can type an exact angle in the rotation field to match a wall drawn at any angle.
Do hanging lights follow the slope?
They hang at the room's usable ceiling height, not from a phantom flat ceiling — a chandelier or fan drops from its mount at the real height under the vault above it.
Does the vault show up in exports?
Yes. Elevation views show the sloped profile, and the vault appears in your PDF, image, and CAD (DXF) exports.
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