Reinforcing a deck for a hot tub
Sorry if this question seems basic, but I'm pretty new to this. Thanks in advance for any advice.
I can get you started.
DEFINITELY use footings. Any deck, let alone one that has a hot tub on it, would have it's concrete block 'move', or experience erosion, on/under them over time. I can attest to that! The previous owner built our free-standing deck on 5" x 5" concrete blocks. Well, by the time I got to fixing them, one block had dropped about 1/2" and another had dropped 11"!!! These blocks are only 1-1/2" thick too. (Hopefully, you're not in the same situation. If you are, I can tell you how to fix it.)
4x4s are fine for your posts. You'll probably need to sister your joists and support them directly. Don't forget to ADD INto your calculations the MAXIMUM weight for adults (along w/the weight of the water.)
Doesn't the Tub Retailer have any info for you? If not, go to Deck Info Spend some of the money you save (by not hiring a Pro) on a good book, at the least. There are TONS of them. Just make sure (or ask) if it contains the info on supporting a hot tub. This would be money WELL SPENT.
Poke around the above link and go from there. Beyond that, when you have more 'particular' questions, perhaps we can help. My best to ya and hope this helps.
Jay J -Moderator
PS: Again, don't forget to add the maximum-people-weight (along w/the water and tub weight) into your weight calculations ...