how thick sould the concrete base be for a 5000 litre water tank and what reinforcing and ratio mix be PLEASE HELP

woman DIY wannabe wrote:
how thick sould the concrete base be for a 5000 litre water tank and what reinforcing and ratio mix be PLEASE HELP 

Answer:
Woman DIY Wannabe,
(interesting screen name!) since most of us engineers still use imperial units I converted 5000 liters to 177 gallons which weighs 11,018 lbs. This is not much weight when distributed across the footprint of the tank. Most tanks actually sit in some sort of frame with legs attached to the ground. Some rest directly on the concrete which further distributes the load. So... worst case scenario, with the tank resting on 4 legs, the weight on each leg is around 3,300 lbs (adding the weight of the tank itself). I'd suggest a 5" thick concrete slab reinforced with welded wire fabric of 6x6xW2.0xW2.0 (that is, 6" wire grid with 8 gage wire) laid in the middle of the slab depth (support the wire with chunks of concrete bricks). This, of course assumes you have good, tight soil to rest the slab on. You can use a standard 3,000 psi commercial concrete mix or sack concrete from your local hardware store. If you are a true DIY'er and are mixing your own concrete, make sure you mix in the amount of water listed on the bag. Go ahead and schedule an appointment with a chiropractor because mixing concrete can be back-breaking work! Good luck with it!