Frequently Asked Questions
How long does concrete last before going hard?
Australian Standards suggest that concrete should be
utilised within 90 minutes of leaving the concrete plant.
Should I place steel reinforcement in my concrete slab?
Concrete is strong in compression (squashing) and
weak in tension (stretching). The introduction of steel
(reinforcement) in concrete improves the strength of
concrete in tension. In a slab-on-ground, reinforcement
increases the tensile strength and helps control the
width of shrinkage cracks. If soil conditions are known
to be poor, eg expansive clay soils, consult a structural
How much concrete does the average concrete truck hold?
Our six wheel concrete trucks delivers 5.6m3 of
concrete. A mini truck delivers 2.5m3 of concrete.
What strength concrete should I order?
25MPa is recommended for small footpaths, driveways,
light footings, residential floors and industrial floors
32MPa is recommended for industrial floors (heavy
For advice regarding strength of concrete for any larger
slabs or construction work, a structural engineer must
Can I receive concrete on a Saturday?
Yes. Saturday is an extremely popular day for individual
home owners to pour concrete. You will need to place
your order early in the week. A Saturday pour incurs a
Can I have ‘coloured’ concrete?
Yes! We have over 50 colours to choose from. Browse
our colour chart online or call into the plant and
personally inspect the colour palette samples. A weeks’
notice will need to be given prior to the pour to allow for
ordering of colour.
How do I make my concrete harden?
Concrete hardens as a result of hydration (the chemical
reaction between cement and water). Hydration occurs
only if water is available and if the concrete’s temperature
stays within a suitable range. After placing concrete, the
concrete surface needs to be kept moist for a period of
time to permit the hydration process.
When should I have my concrete saw cut?
Saw cuts will control shrinkage cracking if they are
installed early enough in the curing stage and they are
cut to the correct depth. To be effective, saw cutting
must be carried out before the concrete starts to cool.
If using a conventional wet saw (the best option as the
cut can be made deeper), this means that cutting must
be done between 4 and 12 hours (as per Australian
Standards) after the surface finishing operations have
ceased. The depth of saw cut for standard joint saws
should be one third the thickness of the slab. If the
saw cutting is not carried out in this narrow window of
opportunity, then it is likely that it will not be effective in
If a slab is poured in the early morning, it is too late to
saw cut effectively the following day.
What can I do to significantly reduce the risk of my concrete cracking?
It is highly recommended that your concreter carry out
the following procedures to significantly reduce the
incidence of shrinkage cracking:
• the site is prepared properly including where control
joints will be;
• steel reinforcement is correctly placed;
• the formwork is level, firm and properly fixed in place;
• the concrete is compacted during placement
• an evaporation retardant (liquid aliphatic alcohol) is
applied to concrete immediately after screeding;
• a curing compound is applied to finished concrete;
• the concrete is saw cut within 4-12 hours after the
surface finishing operations have finished; and
• the concrete is saw cut to a depth one third the
thickness of the slab. Avoid, if possible, executing
major concreting projects on hot days with low
humidity or on windy days. If necessary, start early to
avoid concreting in the middle of the day.
What is polished concrete and can I choose this option for my house?
Polished concrete is used to describe a variety of
decorative concrete flooring options which leave a
concrete surface exposed as the final floor finish. Whilst
more expensive than standard concrete, it is a popular
finish. We only supply concrete aggregate to be utilised
in a polished finish for large house slabs. Call to discuss
What is an expansion joint and when should they be used?
Expansion joints are used primarily to relieve stress
due to confinement of a slab. An expansion joint should
always be utilised where concrete will join an existing
structure of any type. This would include a junction of
footpaths, footpath with a driveway, building, kerb or
other similar structure, as well as where a floor slab joins
a column, staircase, etc.
The function of the joint is to relieve stress concentrations
and to control or minimise the size and location of
potential cracks in the slab. Larger slabs in particular
require expansion joints at regular intervals. Expansion
joints provide an added advantage when a slab is too
large to finish in one pour – the individual sections
created by the expansion joints can be poured one at
What is an evaporation retardant?
A moisture evaporation retardant is designed to be used
on concrete surfaces to reduce evaporative water loss
which reduces the incidence of shrinkage cracking and
enables concrete to remain workable during finishing.
Ever-Ready Concrete sells CCS Aliphatic Alcohol, an
evaporation retardant and finishing compound.
What is meant by ‘curing’ concrete?
The curing period for concrete is approximately 28 days
after placing conventional concrete. New concrete can
be wet with soaking hessian, sprinklers or covered with
plastic sheets. Add only small amounts of water where
possible. Concrete is more commonly cured with a
commercial curing compound which seals in moisture.
Ever-Ready Concrete sells CCS Slab Clad R, a water
based membrane curing compound.
Why does concrete crack?
Like all other materials, concrete will slightly change in
volume when it dries out. This change in volume brings
about tensile stresses with the concrete which causes
it to crack. This is the reason that contractors put joints
in concrete pavements and slabs to allow the concrete
to crack in a neat, straight line at the joint, allowing it to
move when the volume of the concrete changes due to
shrinkage. The prevailing weather conditions may also
contribute to cracking with the risk most likely on warm
days, dry days with low humidity and/or windy days.
What causes surface dusting on my concrete slab?
Concrete surface dusting is typically caused by finishing
the concrete surface too early, while bleed water is still
rising to the surface. Thus working bleed water back into
the concrete weakens the concrete surface resulting in
dusting of the hardened concrete. Generally, repairing
dusting floors is not difficult. If the problem is not severe,
the surface can be repaired by applying a chemical
surface hardener. In severe cases it may be necessary
to grind the floor to remove the weak surface layer and
apply a bonded topping.
How can I remove oil and grease stains from my concrete slab?
Oil and grease stains can be difficult to remove completely
because they penetrate the concrete surface rapidly. If
an oil spill occurs, stop it spreading by encircling with
sand, dirt or sawdust. Soak up as much surface oil or
grease as possible with an absorbent cloth or powder.
Cover residue stain with a poultice made of 1 part lime
to 2 parts mineral turpentine. Spread a 5mm layer of
the paste over the stained area ensuring a margin of 50
to 100mm around edges. Cover with plastic sheeting
and leave for 24 hours. Remove cover and scrape off
the powder. It may be necessary to repeat this process
again within a day or so. Scrub with warm water and
detergent then rinse with clean water at the end of the