AvoGuide · reflected ceiling plan
Measuring ceilings from plans: RCPs, voids, raked ceilings and bulkheads
Take ceiling areas from the floor plans and heights, shapes and features from the sections and the reflected ceiling plan (RCP). Voids, raked ceilings and bulkheads are where ceiling takeoffs go wrong: take each void off the ceiling of the room below it, flag raked and bulkhead areas instead of flattening them, and take heights room by room.
What the RCP tells you
A reflected ceiling plan is drawn as if the ceiling were reflected onto the floor, so it lines up with the floor plan beneath it. It shows what the floor plan can’t: ceiling heights and set-downs, bulkheads, access panels and light positions. Where there is an RCP, use it.
Heights from the sections
Take ceiling heights from the sections, room by room. Height doesn’t change a flat ceiling’s area, but it drives the wall quantities. The ceiling board depends on the framing: Gyprock describes Plus as best for ceilings with joists at 450 mm centres and recommends Supaceil where joists are at 600 mm centres.
Voids
A void on the upper floor plan is open to the room below. The ceiling over the void belongs with the upper level’s ceiling. The ground floor room under it has no ceiling where the void is, so the void’s area comes off that room’s ceiling. Find the room through the ground floor RCP or the sections, and measure the walls around the void at their own (double) height. A rule like “remove every space named VOID” looks right and isn’t — check each one.
Raked ceilings and bulkheads
A raked ceiling is larger than its plan area: divide the plan area by the cosine of the pitch. A bulkhead adds its vertical faces (length × drop) to the flat soffit. Flag both in the takeoff so they are priced as what they are.
Worked examples
| Case | Working | Result |
|---|---|---|
| Living 6.0 × 5.0 with a 3.0 × 4.0 void above | 30.0 − 12.0 ground floor ceiling | 18.0 m² |
| Raked ceiling, plan 20.0 m², 20° pitch | 20.0 ÷ cos 20° = 20.0 ÷ 0.9397 | 21.28 m² |