how much gravel do i put down for a concrete pad for a garage concrete going to be 5 inches thick?

Question

nothings going to real heavy on it

Answer 1

You should contact your town's building permit department. This is a pretty big job and you want to be sure that you get the proper permits and everything is up to code.

Answer 2

I stopped using gravel years ago. I use what they call quarry dust. It is a byproduct from the rock crushing, at does a better job, it is cheaper, and it a lot easier to spread out and get level. It has little gravels in it but they aren't as large as pee gravel.
2 to 3 " is fine.
As someone else said, 5" of concrete will be quite strong. If you use the dust it will be a lot easier to get completely level.
Concrete comes in different strengths. Most people use a 2,500 or 3,000 mix, but I have learned over the years it is far better to pour an inch thinner and use a higher straight concrete.
By dropping from 5"'s to 4"'s the price would be about the same if you use a 4,000 P.S.I. mix. You will get a far better finish and it will last a lot longer and have a lot better chance of not cracking.
The only draw back is you have to work faster because the 4,000 mix dries faster. Keep a hose around when you are finishing it.
One other word of advice, if you call the cement company they will have names of contractors. Call them all and get a price from them.
I use a man that pours it by himself and he is good. He will pour a 24' x 24' garage for me for 150 bucks and it looks good. I stopped pouring concrete on my jobs about 10 years ago. Too much really hard work if you don't have the know how, and the ones that have it does a better job than I can, and only God knows how many yards I have poured. If it isn't a footing or a side walk, I don't pour it. It's not worth it.

Answer 3

It's more important to have good compaction under your slab then gravel. And the average gravel someone would put down only leaves voids that the concrete has to fill, making the bottom of you slab just a high aggregate concrete mix. If you really want to make the slab last, put down a good base material and compact well before you pour your slab. Also, at least add some wire to the pour, placed in the bottom 1/3 of the concrete, or use #4 rebar at 12" to 18" on centers.

Answer 4

The amount/type of base material depends on how well your soil drains. If you have a clay content I would place 3 inches of gravel over a WELL COMPACTED BASE. Place a 6 mil vapor barrier.

I would use 4" x 4" welded wire mesh to reinforce a 4 inch slab - you do not need 5 inches to support autos. Try to buy the welded wire in unrolled squares - this is much easier to place in a manner that assures the wire is not too close to the top or the bottom of a concrete pour. If you use stones as chairs (as many people/contractors do) to support the welded wire be sure they are not dislodged during the pour - if they are dislodged that portion of the wire will be forced to the bottom of the pour and your slab strength will be lessened.

Answer 5

The gravel provides a buffer of sorts to distribute forces, and a way for moisture to drain. Many people don't use sand or gravel at all; as a builder- I always do. Typically I put in about 3". A 5" slab will be quite strong, most drives and garages are 4".

Answer 6

Up here in Minnesota we dig down to good solid clay. Black drit doesn't drain well and holds moisture so we go down to a good solid base and bring it back up with fill usually sand. I agree with Jeffrey I would rebar no more than 18" x 18" on center thats plenty for a garageand then I would go with a 4,000 lb mix like Dennis said you'll come out with a stronger and nicer looking floor. That will be good for you and the next owner as well.

Answer 7

safe building 6 thick concrete roof 25 feet 16 feet supporting beams

Answer 8

usually 4 inches thick of "abc". need it for drainage.