How deep should the form be for a concrete slap for a dog pen?

Question

How thick should a concrete slab be for 10x20 foot dog pen. What type of rock? How thick? and how much of rock then concrete? thanks for the feedback

Answer 1

4" thick concrete slab will work just fine. I wouldn't use mesh, you step on it when pouring the concrete, mesh will end up on the bottom of slab. I always use #40 grade rebar (40,000 lb tensile) in a 4' X 4' grid. For a dog pen with no weight you can get away with 5' X 5' grid saves on rebar.

As for rocks use sand just to level it out, so you don't have 5" in some spots and 3" in others. 2.5 cubic yds of concrete is needed.

The formula is:
length (in feet) X width (in feet)X thickness (in feet) Divide all that by 27. To get inches into feet divide the inches by 12. So 4" in feet will equal 0.33
(10 x 20 x 0.33)/27= 2.47 or 2.5 cubic yds

4" slab is common for most applications, ie driveways, basement floors so on.

Order your concrete as #3500 and a 6" slump and remember you will want to cut your new concrete into
10' X 10' sections to eliminate cracks, all you need is a 1/4" deep cut right down the center.

Answer 2

4" thick. You can poor the concrete on the ground without rock. I would put some 6 X 6 10 - 10 wire mesh in the concrete for strength. You need about 2.5 yards. You can use Readycrete (in a bag) or you can order pre-mix.

If you are going to mix it yourself this is a common concrete mix: 2 part Portland cement, 5 parts sand, 5 parts gravel and approx.1 part water.

The amount of water may vary, but it's important to add a little at a time while mixing.