so i have bought a 3 person hot tub/spa.

it holds about 1600 liters. and its measurements are 2.2m x 1.5m x 0.8m so it should be a wet weight of about 1.6 - 1.7 ton's (excluding people)


now here comes my question i have built some reinforcement for my deck and i'm just asking if it will take the weight. my deck is like this :





and so underneath where the spa is sitting on the deck i have put 2 new 180mm x 45mm joist's that run underneath the current ones that joins the 2 bearer's. from that i have put 2 new joist's joining onto the other new joist's. and i have bolted on 4 100mm x 100mm post's that are attached to gal U brackets/saddles and cemented into the ground.

the new joist's are screwed to the existing bearers by 10 x 90mm gal cork screws (think thats what they where called) and they are joined to the post's via 3 200mm bolts.

this is a drawing of the setup:




one of my main concerns is that i haven't used big enough concrete footings, they're about 400 - 500mm deep and measure about 400mm x 400mm length and width. are these going to take the weight of the spa with out cracking. and how long should i wait for it to harden before i start adding load to it?


thoughts and opinions?


some actual pics of the setup