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  • Slabs & foundations
  • 25–30 MPa

Concrete Roof Slab in South Africa: Free Quotes from Local Contractors

Planning a concrete roof slab? Tell us what you need and independent South African contractors and suppliers will send a free quote. No fee, no obligation.

  • Quotes fromroof slab contractors
  • Areaall nine provinces
  • Cost to youfree

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Workers pouring concrete onto a flat roof slab with steel reinforcing and timber shuttering under a bright sky
Workers pouring concrete onto a flat roof slab with steel reinforcing and timber shuttering under a bright sky

Get a free concrete quote

Tell us what you need and where. A contractor or supplier who works in your area quotes you directly. Free, no obligation.

Pour docketPD 027427

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Length and width in metres, thickness in millimetres. Add a row for each slab, footing or path. The totals go into your request.

#Length mWidth mThick mmQty
1×××
2×××
3×××
0m² area
0m³ concrete
06 m³ trucks

Order about 5–10% more than the net volume to allow for waste and uneven ground.

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A concrete roof slab gives you a flat, solid roof that can carry a patio, a water tank, solar panels or an extra floor later. It is strong, fire resistant and quiet in rain, but it must be designed, poured and waterproofed with care. ConcreteSlab.co.za is a free quote service. You fill in one form and we pass your request to independent concrete contractors and suppliers in your area, who quote you directly. We do not pour, sell or install slabs ourselves. There is no fee and no obligation.

Concrete slab roof or metal roof?

Many owners compare a concrete slab roof with a metal IBR or corrugated iron sheet roof. Both work, and the better one depends on the design.

  • Cost drivers: a slab needs shuttering, props, reinforcing, a pump and waterproofing, and a metal roof needs trusses, sheets and fixings. A slab usually costs more upfront.
  • Heat and noise: concrete holds heat but is quiet in rain. Bare metal heats fast and is noisy, so it needs insulation.
  • Waterproofing: a slab depends on its membrane and falls, while sheets depend on laps and fixings.
  • Load and use: a slab can carry tanks, solar panels or a future floor, and serve as a deck. A metal roof cannot.

Slab types are cast-in-place, rib-and-block, or precast planks, all laid to a slight fall.

Design and loads

A roof slab carries its own weight, the finishes on top, wind and any live load. It may also carry a tank, plant or a future storey. Because of this, an engineer must design it to SANS 10100-1, and your plans must follow SANS 10400.

  • Thickness: a solid roof slab is often 120 to 200 mm, depending on the span.
  • Strength: 25 to 30 MPa concrete is typical, supplied to SANS 878.
  • Cover: reinforcing needs enough concrete cover, and more near the coast where chlorides corrode steel.
  • Edges: parapets, upstands and overhangs are detailed on the drawings.

Waterproofing and thermal care

Most concrete roof leaks come from poor waterproofing, not the concrete. The slab should cure properly and be clean and dry before a membrane goes on. Waterproofing must turn up at walls and around pipes and outlets.

  • Membranes: liquid-applied, bituminous or torch-on systems are all used.
  • Screed: a sloping screed is sometimes laid to create the fall before waterproofing.
  • Insulation: concrete holds heat, so insulation under or over the slab improves comfort.
  • Movement: sun and temperature swings cause expansion, so detail joints and upstands carefully.

See our concrete waterproofing page for specialists in your area.

What affects your quote

People search for the concrete roof slab price, but it depends on the project. We never give prices here. Contractors will look at:

  • The roof area, span, thickness and chosen system.
  • Shuttering, props and reinforcing.
  • A concrete pump, which is almost always needed for roofs.
  • Part-load charges, delivery distance and truck access.
  • Screed, waterproofing and insulation.

Send your engineer's drawings for the clearest quotes.

Comparing quotes for concrete roof slabs

The lowest figure is not always the best deal. When your quotes arrive, check:

  • Specification: the thickness, the concrete strength in MPa, the steel and the membrane, so every quote is for the same work.
  • Preparation: excavation, sub-base compaction, shuttering and who removes spoil and rubble.
  • Concrete and access: ready-mix or site-mixed, whether a pump is included and any part-load or waiting charges.
  • Finish, curing and guarantee: the surface finish, how long it will be cured, where joints are cut and what guarantee covers the work.

What to include in your request

  • Attach the engineer's drawings or give the roof area and spans.
  • Say which system you want, or ask suppliers to suggest one.
  • Mention the height, access and whether a pump is needed.
  • State if waterproofing and screed are included.
  • Add your town and your pour date.

Frequently asked questions

Does ConcreteSlab.co.za build concrete roof slabs?
No. ConcreteSlab.co.za is a free quote service. You send one request and we pass it to independent concrete contractors, ready-mix suppliers and precast makers near you. They contact you directly with a quote. We do not pour, sell, deliver or install anything, and there is no obligation.
Do I need an engineer for a concrete roof slab?
Yes. A roof slab carries significant weight and must be designed by a competent person, usually a registered engineer. The design sets the thickness, reinforcing, props and curing. Your municipality and the NHBRC for new homes will expect the drawings with your plans.
How do I stop a concrete roof slab from leaking?
Cure the slab well, lay it to a fall, and apply a proper waterproofing membrane once it is clean and dry. Detail the edges, pipe penetrations and outlets with care. Check the roof after the first heavy rain and repair any defects early.
Can I build a second storey on a concrete roof slab later?
Only if it was designed for that. Tell your engineer at the start, so the slab, walls and foundations are sized for extra load. Starter bars can be left sticking out of the slab for future columns. Adding a floor without checking can be dangerous.

Concrete Roof Slabs by province

Concrete Roof Slabs by city and town

SurfaceFloors & finishes
SlabSlabs & foundations
MixReady-mix, pumping & materials
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