Quandaries and Queries


My name is Armand, I am not a student nor a teacher but a
retired renovator and I'm embarrassed to have to ask this question. I am
planning to pour a concrete slab over an existing slab in my garage
which is very uneven, with a depth variation from 2 1/2 inches to 5 1/2
inches from level. I'm afraid to over estimate concrete since it will be
wasted but worse, I'm afraid to underestimate. I've broken the slab down
into four sections with the following being the four dimensions, can you
tell me how much concrete I will need please, I would very much
appreciate your help.
1- 6ft/8in x 20ft x 4 1/2 in. thick
2- 16ft/10in. x 20ft x 3 1/2 in. thick
3- 6ft/6in. x 16in. x 5 1/2 in. thick
4- 6ft/6in. x 8ft. x 4in. thick

Very best regards,



Hi Armand,

Since you want the volume of concrete in cubic yards I would first change all the dimensions to yards. For example in the first slab

6 ft 8 in = 6 12 + 8 inches = 80 inches
and 80/36 = 2.22 yards

20 ft = 20/3 yards = 6.67 yards

4.5 inches = 4.5/36 = 0.125 yards

Thus the volume of the first slab is

2.22 6.67 0.125 = 1.85 cubic yards

I did a similar calculation for the other three slabs to get a total of

1.85 + 3.64 + 0.15 + 0.64 = 6.28 cubic yards.

You should check my calculations.



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