Slabs
Every room's floor and ceiling come from its walls. A slab is the floor no walls enclose: a terrace, a balcony, a landing or a porch, drawn corner by corner, with its thickness, its level, its edge detail and the falls that drain it.
Every property, and what it does
Select a slab and these are its rows: its level and thickness first, then its edge, its falls and its materials.
Slab
Where the slab is and how thick.
| Field | What it does | Values |
|---|---|---|
| Height | The slab's level, measured from the storey's floor. Snapped onto a beam, it takes the level that beam gives it. | Millimetres; default 0 |
| Thickness | How thick the slab is. Until it is given its own, it takes the storey's floor thickness. | Millimetres, 1 and up |
| Function | What the slab is for. Groups schedules and takeoff, and maps to IFC. | Auto, Floor, Roof, Landing, Base slab |
| Area | The slab's area. | Read from the plan |
Edge
How the rim is detailed.
| Field | What it does | Values |
|---|---|---|
| Detail | How the rim is finished. Square is the plate as poured. | Square, and the edge details the panel offers |
| Run, Concrete | The length of the detailed edge and the concrete it takes. | Read from the slab |
Falls
A terrace or a flat roof falls to a point so it drains.
| Field | What it does | Values |
|---|---|---|
| Fall points | Where each drain point is, and how far the plate falls to it. | Points on the slab |
| Laid as | Screed: the pour stays flat under it. Cast: the soffit follows and the depth is constant. | Screed, Cast |
Materials
The finish of each face, and the layers through the slab.
| Field | What it does | Values |
|---|---|---|
| Top, Underside, Edge | The finish of each face of the slab. | Any project material |
| Build up | The layers through the slab, each with its function, thickness and material. | Any number of layers |
How the Slab tool works
Open the Slab tool
In the editor, open Build and choose Slab, or type SLAB (SB).
Click each corner
Click each corner of a floor no walls enclose: a landing, a balcony, a porch. Click the first corner again, or press Enter, to close it.
Set its level
Select it to set its height and thickness, and its function for the schedules.
Detail it
Give it an edge detail, falls to a drain point, and a finish on each face.
Slab questions, answered.
Do I draw a slab for every floor?
No. Each storey's floor and ceiling plates come from its rooms on their own. A drawn slab is only for a floor no walls enclose.
Can a terrace drain?
Yes. Falls slope the slab to a point. Laid as Screed keeps the pour flat under the fall; Cast slopes the whole plate.
Can a slab have layers?
Yes. A build up stacks the layers through the slab, each with its own thickness and material.
Read on
- Wall Design: Walls make rooms, and rooms make floors.
- Shafts: Holes through the floors for lifts and light wells.
- Walls and rooms docs: Drawing walls, build ups, rooms, slabs and shafts.