Building Deck question?

[hjscm]

Ok so i have the d1 amore bay coming in about 3 weeks. I am building a deck about 30" off the ground on a concrete pad.  Going to put hot tub on top of deck.  the whole deck is about 1,100 sqft.  its all being built with 2x8 joist and 4x8 beams, with 4x8 post anchored into concrete.  beams are about 7' spread. where the hot tub is going i put extra beams at about 3' spread. so one beam in about center of tub, about 3/4 out i have beams and about 2' outside of tub more beams.  do you think this will be strong enough?

[Tman122]

Ok so i have the d1 amore bay coming in about 3 weeks. I am building a deck about 30" off the ground on a concrete pad.  Going to put hot tub on top of deck.  the whole deck is about 1,100 sqft.  its all being built with 2x8 joist and 4x8 beams, with 4x8 post anchored into concrete.  beams are about 7' spread. where the hot tub is going i put extra beams at about 3' spread. so one beam in about center of tub, about 3/4 out i have beams and about 2' outside of tub more beams.  do you think this will be strong enough?

I'm not an engineer to do load calculations but YES.

[Beck0101]

What size is that tub?

I decked under my 8 person tub.  I don't have my drawings handy but I seem to recall using 2x10's for beams, 2x8's for joists, 6x6 for posts.  12" spacing on the joists, 6' spacing on the beams with 5' spacing on the posts, 18" max overhang.  48" deep footings.

Make sure you notch the posts and block the joists.

[bud16415]

First off where are you located and what is the freeze depth in your location. A concrete pad is not the same thing as a footing that goes below the frost line. Your pad now is free to float and move with frost. If you live in southern climate without frost then the recommendation would be different.

Keep in mind a 6 person tub is around 800 pounds empty and about 6000 full of water add another 800 pounds of people plus the weight of the deck.

Next question will the deck be attached to the house with a ledger board or free standing?

It is possible to build a free standing deck without footings and build it in such a way it will float and move with frost. That is how I built mine and it is 12’x16’. As to structure you sound like you are strong enough. I would suggest building the whole deck with deck screws and not nailing. I also would suggest diagonal cross bracing if it wont be attached to the house.     

[Clarkp]

You might have a look through this post:
https://www.whatsthebest-hottub.com/forum/index.php/topic,21386.msg205152.html#msg205152

You'll see a couple of different approaches to your issue.  By 'beams' I'm assuming you mean treated timbers, not cedar.  Cedar is not structural, and as Beck0101 mentioned you need to notch your support posts to hold the load - don't lag bolt support beams to the posts.  Look at the pictures in the above post, I think some of what you're interested in starts on page 4 (or maybe before...)

Jukeboxpunk and I approached the problem differently.  I used the laminated structural beams (doubled on the interior) from Boise Cascade.  Generically, they're called 'LVL's at the lumber yard.  Mine are 9" inches deep and they're about 2" wide.

Remember too that when you're in there with three pumps running (Sundance Aspen here..) you're hammering the foundation at a low frequency and a lot of weight.

Better to ere on the side of over-building IMHO... 

[hjscm]

So it sounds like i should be fine.  I live in bay area california so frost is not to much of a problem, plus my concrete slab is 8" thick.  my 2x8 all pressure treated sits on top of 4x8 beams and i went with 4x12 post under the tub.  thanks for the replies