Steel reinforcing mesh is used in driveway slabs to control the width and length of cracks in concrete. If the mesh is “walked in” or placed at the bottom of the concrete slab, it is ineffective and won’t control cracks. Ensure your mesh is correctly positioned when pouring by chairing it on bar chairs at 1000 x 1000 centres.
Does a Concrete Driveway need Black Plastic
I was also asked recently if driveway slabs need the black plastic membrane (200 micron polyethylene membrane) under them before pouring.
If you have the plastic on site, then I recommend using it. The purpose it serves is to prevent the dry ground sucking moisture out of the wet concrete. That moisture is needed by the cement powder in the chemical reaction called hydration. Don’t worry if your driveway slab has already been poured without the plastic membrane. Not having it won’t decrease your slab’s strength too much – especially if your concreter wet the ground before pouring.
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The rules for building near existing council-owned buried infrastructure (including sewer mains, stormwater pipes and underground electrical cables) vary from region to region. There are two main reasons for these rules.
They want to be able to access their pipes safely;
They don’t want your structure to collapse into their trenches.
Keep this in mind when constructing over or near sewer mains, stormwater pipes and electrical cables.
Here is a video that explains the rules a little bit more.
The rules for building over or near sewers changed in November 2013. Under the new approval process, building work over or near a sewer must be assessed against Queensland Development Code Mandatory Part 1.4 (MP 1.4).