Stand Alone Hot Tub Deck, Is It Sufficient? - Building & Construction - Page 2 - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools
Display Modes
Old 08-03-2015, 11:34 PM   #16
Member
 
Join Date: Feb 2014
Posts: 4,809
Rewards Points: 4,772
Default


Once you start playing with the numbers, you soon realize how it's possible to drive a pickup over two 2 by's. A video of this was posted by a member here.

If you just calculate the joist and spacing only, not counting the unsupported portion you get...

The Maximum Horizontal Span is:
8 ft. 1 in.
with a minimum bearing length of 0.85 in.
required at each end of the member.
PropertyValueSpeciesSouthern PineGradeStud (Eff. 6/1/13)Size2x10Modulus of Elasticity (E)1170000 psiBending Strength (Fb)546.25 psiBearing Strength (Fcp)378.55 psiShear Strength (Fv)169.75 psi

Here's some specs on a similar hot top...
Seating Capacity 6-7 Adults Dimensions 91 in x 91 in x 39 in - 44 in back / 231 cm x 231 cm x 99 - 112 cm back Average Spa Volume 450 US gal. / 1,703 Liters Dry Weight 950 lbs. / 431 kg Total Filled Weight 5,620 lbs. / 2,549 kg - See more at: http://www.jacuzzi.com/hot-tubs/j-40....kOzps60h.dpuf

ron45 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 08-03-2015, 11:43 PM   #17
Newbie
 
Join Date: Aug 2015
Posts: 8
Rewards Points: 6
Default


Ron, my tub is 76x76x34, 295 gallons 6 person.

So you think I should tie it in to the ledger board on the part 2 deck? All of the calculations I've done have told me this structures hold that load.
Copgtp is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 08-03-2015, 11:46 PM   #18
Member
 
Join Date: Feb 2014
Posts: 4,809
Rewards Points: 4,772
Default


I think you should get the tub I listed.
Your unsupported joist length is only about 2'-2" to 2'-4" right.?
Way less then the 8'-1"... And that was calculating a combined live and dead load of 120 psf.

Last edited by ron45; 08-03-2015 at 11:50 PM.
ron45 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 08-03-2015, 11:52 PM   #19
Newbie
 
Join Date: Aug 2015
Posts: 8
Rewards Points: 6
Default


I like the one you listed! Maybe when this one gets replaced. I see why some are concerned about the dynamics of the water,I'll put some z bracing up. I've seen tubs on less, but I guess there's only one way to find out.
Copgtp is offline   Reply With Quote
Old 08-03-2015, 11:59 PM   #20
Member
 
Join Date: Feb 2014
Posts: 4,809
Rewards Points: 4,772
Default


You said you seen tubs on less...
I would have put a 4" thick slab, 2 x 4 walls with a door, 4 floor joist, 3/4" treated plywood. The bottom would have been a storage place and easy access.
ron45 is offline   Reply With Quote
The Following User Says Thank You to ron45 For This Useful Post:
Copgtp (08-04-2015)
Old 08-04-2015, 12:46 PM   #21
Member
 
Join Date: Jul 2015
Posts: 477
Rewards Points: 948
Default


Quote:
Originally Posted by Copgtp View Post
There won't be a step or railing on this platform, when the hottub is on it, and the actual deck is up, you'll never see this platform unless you're underneath.

As far as the z bracing, that's a good idea, I think I will do something like that.

I'm wanting tie-backs or angle bracing (from the foundation, or beyond the platform.) The concerns I have are inertia of the water, lateral/dynamic loads, and/or uneven distribution of the load (across nine footings) leading to tilting of the platform. You've built it exclusively to handle static loads.

(I would much rather have seen two appropriately-sized footings on the down slope, and a steel angle ledger on the building side. The stiffness of the deck isn't difficult to achieve, just run joists on closer centers.)

Make sure your z-brace is as I described on the sides, tension-compression-tension with respect to the slope. Top across, top right to bottom left, bottom across. (Steel angle bracing underneath, bottom rear to top front, diagonally.) I think you should run this by a local engineer to be safe.
keymaster is offline   Reply With Quote
Old 08-04-2015, 01:37 PM   #22
Member
 
Join Date: Jul 2015
Posts: 477
Rewards Points: 948
Default


Also, the design of the platform (free standing, on three beams, nine footings, top heavy) also raises concerns of the platform shifting or racking in a direction parallel to the beams/foundation. An analogy is how comfortable are you placing a heavy aquarium on a high table with nine legs?

It needs some sort of stabilization laterally as well. It could come by way of steel angle from a steel ledger at the foundation. (Which would have been adequate support for the platform on two legs in the first place.)
keymaster is offline   Reply With Quote
Old 08-04-2015, 10:48 PM   #23
Member
 
Msradell's Avatar
 
Join Date: Sep 2011
Location: Louisville Kentucky
Posts: 2,808
Rewards Points: 910
Default


Quote:
Originally Posted by keymaster View Post
Also, the design of the platform (free standing, on three beams, nine footings, top heavy) also raises concerns of the platform shifting or racking in a direction parallel to the beams/foundation. An analogy is how comfortable are you placing a heavy aquarium on a high table with nine legs?

It needs some sort of stabilization laterally as well. It could come by way of steel angle from a steel ledger at the foundation. (Which would have been adequate support for the platform on two legs in the first place.)
While I think that a little more "Z" bracing may be appropriate that's about it anything else would be major overkill. Actually what he has already is overkill as far as vertical support goes. Once the rest of the deck goes around this platform there is no way that the platform with a hot tub on it can rack anyway. The other deck will be tied to the house and support lateral movement of this platform.
__________________
Written using Dragon Naturally Speaking
Msradell is offline   Reply With Quote
Old 08-04-2015, 11:43 PM   #24
Member
 
Join Date: Jul 2015
Posts: 477
Rewards Points: 948
Default


Quote:
Originally Posted by Msradell View Post
While I think that a little more "Z" bracing may be appropriate that's about it anything else would be major overkill. Actually what he has already is overkill as far as vertical support goes. Once the rest of the deck goes around this platform there is no way that the platform with a hot tub on it can rack anyway. The other deck will be tied to the house and support lateral movement of this platform.
So a second deck will support the deck, is that correct? I suppose you don't really need to build decks that can stand as long as you build enough of them that they lean on each other.

IRC requires lateral load devices be attached to non-ledger decks, which attach the deck to the building. The IRC specifies tensioning devices or hold-downs, and the method of attachment to the building.

Or, he could have just used a ledger. But either way, it needs to be tied to the building to resist lateral loads (especially given how he built it).
keymaster is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Rooftop deck change: why is there a leak now? stripedbass Carpentry 0 02-24-2015 04:32 PM
Pool Deck Cantilever nooneisathome Building & Construction 2 09-20-2014 10:13 PM
Deck Stain? pomlady7 Painting 13 05-24-2014 05:58 PM
22x14 DECK W/ROOF SLIGHT SWAY NEED HELP FROM EXPERTS clfdpops1 Building & Construction 38 06-09-2012 07:21 PM
Building Floating Deck over ground and Concrete slab jagnew Building & Construction 2 05-27-2012 01:10 PM




Top of Page | View New Posts