What is demolition?

What demolition means

Demolition is taking a structure down on purpose, in a planned order, so that it comes down where and when it's meant to, and leaving the site clear and safe. A house demolition covers far more than knocking walls over: the services are cut off, hazardous materials removed, salvage stripped out, the structure brought down, the slab and foundations broken out, the rubble sorted and carted, and the holes filled.

The law treats it seriously because a half-demolished building is unpredictable. Regulation 14 of the Construction Regulations, 2014 puts every demolition under a competent person appointed in writing, and the municipality decides whether a building may come down at all.

The order of work: how a building comes down

A demolition follows the reverse of construction: last in, first out. The order matters for safety (nobody under unsupported parts of the structure, which regulation 14 forbids) and for cost (clean, sorted rubble is cheaper to get rid of).

1. Survey and method. For anything more than a simple house, an engineer surveys the structure and a written method statement sets the order of work. Regulation 14 requires both.
2. Services off. Electricity, water, gas and sewer disconnected and made safe at the boundary, and their positions established before work starts.
3. Hazardous materials out. Asbestos roof sheets, gutters, downpipes and ceiling boards come off first, by a registered asbestos contractor, with a clearance certificate before any machine moves in.
4. Soft strip and salvage. Doors, windows, fittings, geysers, roof sheets and roof timbers come out by hand.
5. Roof structure, then walls from the top down, pulled inwards, away from the street and neighbours. Floors above ground come down before the walls that hold them.
6. Slab and foundations broken out with the breaker; pool shells broken and holes left by basements opened up for filling.
7. Sort and load. Concrete and brick, steel and timber kept apart where possible and loaded onto tipper trucks.
8. Fill, compact and level. Foundation trenches and holes backfilled in compacted layers, and the site left level and safe.

The municipality can forbid a demolition method it considers dangerous to people or property (regulation E3), and a part-demolished building may not be left in a dangerous state. Our operators bring buildings down from the top, away from people, with nobody inside the danger zone.

Demolition contractor licence: what's actually required

There is no single "demolition licence" in the rules above. What a demolition contractor must have depends on the job:

• A competent person appointed in writing to supervise the demolition, with the engineering survey and method statement regulation 14 requires.
• The regulation 4 notice to the Department of Employment and Labour before demolition, excavation, work at height or blasting.
• A registered asbestos contractor for any asbestos removal, appointed alongside an approved inspection authority, with a clearance certificate at the end.
• Certified machine operators. Excavators, TLBs and bobcats are mobile plant: the operator must be trained, certified competent, medically fit and authorised in writing (Construction Regulations, regulation 23).
• A CIDB grading for public-sector work. Government and municipal tenders state the CIDB contractor grading designation they need, and only contractors registered at that grade or higher are evaluated.

We send demolition machines with certified operators, and copies of their certificates come before the machine, on request. See safety and certificates.

Rubble: how much, and where it goes

Clean demolition rubble (concrete, brick and soil) weighs about 1.07 t a loose cube. A 10 cube tipper carries about 10.7 t of it, and is R3,700–R5,250 a day with operator with its driver, or about R2,300 a load on short runs in Gauteng. Landfills charge by mass on their weighbridge, so sorted, clean rubble (or rubble taken to a crushing site) costs less to get rid of than mixed waste. The conversions are in how many cubes in a ton.

For the machine side, three days of a 20–25 t excavator come to R10,500–R16,800 and three days of a breaker TLB R15,000–R19,650, before transport, tipper loads and VAT. Worked examples with transport are on demolition; every machine price is on plant hire rates.