RDrancher
Veteran Member
I would like to ask a question.If I am out of line,please let me know and we can chat in PM.
In a few years I am planning to build a 30x40 garage.The drive way up is fairly steep grade.From the road to the front of the shop,the vertical rise is 15 feet over a 90 foot run.I will be bringing vehicles in and out with a GVWR of no more than 30,000lbs.What would you suggest for the drive way,pavement or rebar reenforced concrete?What should the thickness be?My building slab will be 6 inch rebar reenforced concrete.The reason I ask is,at my house the driveway pavement mars every time I jack a vehicle up.Heck,my porch swing even marred up in the pavement.
Ben, if the cost doesn't deter you, I'd opt for concrete, mainly because of the slope. Even though 4" thickness will handle the weight, if you have them pour at 5" you can spec "4 rebar for reinforcement. A lot of guys will place #4 rebar in 4" concrete, but its too large and if it's set on rebar chairs its too high in the slab and can lead to premature surface cracks. Sometimes bigger isn't better.
I like to thicken up the perimeter of the slab for extra strength. On a slope, the extra depth can also help to keep water from getting under the concrete and forming voids. At the bottom of the slope, the little footing helps to stabilize the slab. 6-7" around the perimeter is plenty...thicker can lead to settling and crack the slab down the middle. I'd also go with fibermesh, it's fairly inexpensive and really does help keep micro-cracks at bay. There are plenty of admixtures to choose from...water reducers increase strength by making the concrete more workable at a lower slump and air-entrainment helps in the freeze-thaw cycle. Finally, make sure the contractor places 3/4-1" deep tooled joints at no more than10' intervals to control random cracking and then applies a semi-heavy broom or textured trowel finish to give you plenty of traction.