Step one is to dampen the soil. Loose soil cannot support a concrete slab or its base.
Utilise a line level and string level or builder’s level to determine how steeply your site slopes, and as necessary add or remove soil accordingly, building up low sides while digging away high ones if necessary.
The Base
An ideal foundation for any concrete house slabs Melbourne should include gravel, crushed rock or another suitable material that can be compacted for its intended use. If unsure which foundation best suits your project and soil conditions, speak with a local concreting professional and they may offer some suggestions on which options may work.
If your shed floor will be installed on a sloped site, it is essential that all sides slope away from it for at least ten feet on all sides in order to avoid water pooling in and around it. This will help avoid pooling as water accumulates within or on top of it and disrupting its design.
Subbase thickness matters when it comes to supporting loads for slabs. A thicker subbase can increase load bearing capacity while at the same time blocking capillary action from groundwater entering into the slab from below, so adding one even if your slab will not be heavy is wise.
The Forms
Before pouring a concrete slab, it’s necessary to prepare the site. This involves driving stakes around each corner of the new slab and stringing a line level between stakes to see how much the site slopes; if sloped areas must be addressed by adding fill.
Once this has been accomplished, dampen the soil before compacting and tamping it down using a hand tamper to form a stable subgrade that will help prevent cracking in concrete slabs.
Before pouring concrete, recruit help from your friends or relatives to spread and tamp it down to the appropriate thickness. It is crucial that the proper concrete mix for your project be used as well as having the ideal water-to-cement ratio; you will also require reinforcement (rebar). Tie bands of reinforcement to stakes placed around the perimeter for strength before adding grids of reinforcing within forms to reinforce as it sets. Finally, you will require a screeding tool for smoothing over wet concrete surface areas.
The Concrete
If you’re installing a concrete slab over an existing one, make sure it can handle the extra height from a new pour. If not, repairs or replacement may need to be performed instead of covering up existing concrete.
Wet concrete can be extremely hazardous, so it’s crucial that anyone walking on it be wary. Additionally, contact with wet concrete could result in serious burns if it comes into contact with the skin – therefore wearing protective gear like gloves and safety glasses is advised for optimal safety.
Once your slab frame is in place, level it and drive stakes into its corners to mark out where to install your slab. Stretch a line of string between these to determine its slope.
Hand tamping soil will help prepare it for new concrete. Compacted soil helps lower risk of cracking down the road. You can purchase pre-compacted soil at landscaping centers and home improvement stores.
The Finishing
Be it for outdoor or indoor use, it’s vital that the site be cleared of debris before pouring the concrete slab. Consult local authorities on what permits are needed and how close you can build.
If the soil is loose or contains expansive clays, adding a base layer may be necessary. A good way to do this would be laying 5-7 cm of road base or crusher dust as a bed, rake it flat before tamping down securely.
After pouring concrete, using a magnesium (mag) float to provide an ultrasmooth finish is one option; alternatively you could drag a concrete broom over its surface to produce a hard troweled effect is another way. Finally, crack control cuts can also be added directly onto its surface in order to direct any future cracking towards specific directions rather than random patterns.