- Set out slab size according to plans for building.
- Achieve final subgrade level by screeding sand or crusher dust
- Dig edge beams and footings as required
- Setup formwork to exact size of slab, take care that formwork is straight and firmly supported to withstand pressure of concrete
- Lay plastic moisture barrier (seal with duct tape where lapped)
- Place reinforcement steel (lap as specified by manufacturer) place bar chairs at max 1000mm crs to hold steel at the correct height (check plans for height of reo).
- Make sure reo is free from formwork by 30mm to 50mm.
- Check plans for control joints and cut mesh if required.
- Place pre-mixed concrete (adding water to concrete can lower strength and increase shrinkage – cracking).
- Generally “slump” shall be 80 to 90.
- Use a mechanical vibrator when placing concrete, this will release air from the concrete and therefore increase the strength of your slab and minimise the occurrence of shrinkage cracks.
- Vibrating will add approximately 10% to the volume of concrete required. Machine trowel the floor to required finish (hand trowel finish will generally not provide the same surface hardness).
- Immediately after finishing floor, cover floor with plastic or spray with curing oil in order to stop evaporation (to cure to design strength moisture is required in the slab)
- Curing to design strength takes 28 days