I hope I'm asking the right people about this. My question is regarding the proper procedures for extending my concrete driveway with some brick. I'd like not to use mortar or concrete. The extension would be approximately 2 ft wide and the length of my driveway (maybe 15 feet).
I understand that, to do this right, I should be digging and laying some layers of different types of gravel. My understanding is that this provides a firm foundation without the concrete and possibly some drainage solutions. But it also pushes way past my budget.
Most of the research I've done recommends that I did down 10-14" for these sublayers. But I wonder if this is really necessary. I live near Tucson, AZ where the frost line doesn't exceed a few inches. Would it suffice to drop a single layer of rock just a couple of inches deep beneath my brick extension? I'd imagine completing the process without any sublayers would result in the extension bowing under pressure.
Also, I believe my driveway slab is only 6" thick. I've already seen shifting and cracking on my slab, other driveways, and sidewalks in the neighborhood. Would digging below the baseline of the slab create an entry way for water, loosening the soil and possibly creating more shifting problems?
Like everybody else on this site I want to minimize cost but do the job right. It is likely the weight of a car would rest on this brick extension, even though it's main purpose is for foot traffic.
Any explanation, comments, or recommendations are truly appreciated.