I'm building a home office/game room extension off my garage, and I need some help with calculating the concrete for my slab. The dimensions for the slab are 16x16 feet, and it will be 4 inches thick. I'm also adding thickened edges on three sides, which will be 10 inches deep and 10 inches wide, sloping slightly back up to the pad.
In my calculations, I figured that I need about 4 yards for the slab itself and 1 yard for the thickened edges, making a total of 5 yards. I'm considering ordering 6 yards just to be safe, but I'm wondering if I should go for 7 yards to avoid any shortages. Any advice?
3 Answers
If you're still unsure, check out a concrete calculator online. But from what you've described, I think 6 yards is more than enough. Just remember, sometimes the digging can change things up; choosing to account for a little extra is always a good strategy. Plus, if you have leftover concrete, you could always consider pouring a small pad for an air conditioning unit or a little stoop at the entrance!
You definitely want to clarify if that slab is 4 inches thick, not 4 feet! Assuming it's 4 inches, your calculations sound about right. For a 16x16 slab that's 4 inches thick, you're looking at just under 4 cubic yards of concrete, plus some extra for the thickened edges. Aiming for 6 yards should be sufficient, especially with any potential waste or miscalculations. Honestly, 7 yards would give you plenty of cushion to avoid running short, especially if you're worried about getting it right this time. Better safe than sorry!
What if you end up with more slab than needed? Can you save leftovers for future projects?
I did the math too and figured it out to be about 4.4 cubic yards for both the slab and the edges. If you're worried about your calculations, 6 yards is a solid choice, especially if you're factoring in spills and mis-measurements. Better to have a little extra than to run short, trust me! It's not just the math; the digging often throws you off too. Plus, the thickened edge is only on three sides, so that might change your numbers a bit. But yes, six yards will cover you well in most scenarios!
Definitely keep a little extra; you never know what will come up when you're pouring!

Good idea! An entry pad would be practical, especially in winter up by Lake Superior!