Driveway Slab Reinforcement and membranes

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.

Got a structural engineering question? Ask us on the contact page or comment here!

Matt Cornell
Cornell Engineers

Five Questions with Craig Bullen

 House Raise and Build in Under Project

Craig Bullen is the Owner/Manager of RE/MAX First Residential, Coorparoo.

Craig ran his own house raise project in Coorparoo which finished construction in 2013.

Craig Bullen

We caught up with Craig Bullen after his project finished and asked him 5 questions about his house raise and build in under renovation project.

Describe the scope of your project?

Full raise and rebuild of a Queenslander.

What is the best feature of your project?

Huge rear patio with Cathedral ceilings overlooking the yard and pool.

What simple lesson have you learned during this project?

Compromise is unavoidable.

Would you attempt a similar project again?

Yes, because by the 5th time I have done it I will know what I am doing… 🙂

How did Cornell Engineers add value to your project?

Matt came up with a great design for engineering and was available for solutions as problems arose. Very happy with the service.

Thanks Craig Bullen

Talk to Craig Bullen about real estate in Brisbane. Here’s his link:

Thank you Craig.

Want to Know More?

Planning a house raise and build in under project and want to know more?

We have some great resources for you right here on our website.

Check out this handy article:

Building over sewers

Build over a Sewer

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.

  1. They want to be able to access their pipes safely;
  2. 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).

The Department of Housing and Public Works has information on MP1.4.  This is the manual we refer to when preparing a build over sewer application in Queensland.

Need Help?

We’re here to help. Would you like Cornell Engineers to assist with your Build over Sewer applications? Get a Quote.