Civil Drawing: Foundation to Slab

Civil Drawing: Foundation to Slab

A single-storey building is described by a set of related drawings, all in first angle under SANS 0143.

• The floor plan is a horizontal section taken about 1 m above floor level, looking down. Walls appear cut and are drawn thick; doors and windows appear as openings in them.
• The elevation shows a face of the building from outside.
• The sectional elevation is a vertical cut, showing the build-up from the ground up: foundation, wall, damp-proof course, surface bed and floor finish.

Standard build-up, ground upward: excavated trench → concrete strip foundation → substructure brickwork → DPC (damp-proof course) → surface bed on compacted fill → floor finish.

Scales. Floor plans are commonly 1 : 100 or 1 : 50; details 1 : 20 or 1 : 10.

Worked example. The DPC is a thin line, but omitting it is a serious error — it is the layer that stops ground moisture rising through the wall. On a submitted plan its absence is a defect, not a missing detail.

Core checkpoint: A floor plan is a section, not a top view. That is why the walls are drawn as cut material.