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Discussion Starter #1
We have an existing balcony on our house (I will detail construction below). Just wanted to see if I could put our small hot tub on it. Tub holds 140 gallons of water an total weight (including 2 people) is less than 2,000-pounds.

The balcony is 14.5 by 14 with 2x10 (southern yellow pine) 16 inch on center construction. Joist hangers were used to connect the joists to the ledger board and the beam. The flooring is 3/4-inch OSB and sealed with a rubber EPDM membrane.

The ledger board is connected to the house by 1/2-inch lag bolts at each stud (old balloon construction without a rim joist). The beam is a double 2x10 (AC2 treated). The posts under the beam are 6x6 with a span of 6.5-feet. Half of one side of the balcony has the joist lag bolted directly to the house studs with 1/2-inch lag bolts. The other side has a double 2x10 joist with 6x6 posts under it at 4-feet and 9-feet. The entire structure has 2x10 blocking at 4-feet and 9-feet.

The posts rest on the concrete porch edge that is a monolithic pour 5-feet thick (36" below ground and 24" above ground).

Of note: The outer edge of the balcony was recently rebuilt (due to water damage). Brand new beam and new joist hangers. Even though none of the joists were damaged, we sistered new 2x 10 material to the outer 3-feet of each joist and used new double 2x10 hangers.
 

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Post some pictures so we can see what your seeing.
Would be interesting to see how the ledger was tied into the studs and properly flashed.
If it was mine I'd be looking for a real onsite real engineer looking at it and signing off on it, not asking for well meaning guesses on DIY sites.
Way too much liability involved for guess.
 
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Discussion Starter #3 (Edited)
I will see what I can post up. Not sure what you will be able to see... I have tried to find a local engineer to inspect this; but, nobody is wiling to come take a look at it (we live pretty far out of town and they are all "too busy"). I have an architect that is telling me the design is perfectly able to support the weight. The hot tub company is telling me that the construction will support the weight (the tub is designed to be used inside a house on standard floor construction). But, I just feel leery about relaxing in the hot tub without another opinion...

The ledger board is lag bolted directly to the studs (balloon construction).

Flashing was placed under the siding and over the OSB. The rubber was then sealed to that flashing. Then rubber tape flashing was placed over the siding and out onto the rubber flooring to further seal the area.
 

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I'd be inclined not to do it. At least not without an engineer's sign off and most likely some major upgrades to the structure.
My issue is that even if it is fine today and next year, every deck I ever see has some rot or other defect developing over time (just like you mentioned about how yours needed to be repaired recently). Most of these decks don't catastrophically fail before repair/replacement because they don't see the kind of loads that a hot tub would put on them.
If you live in earthquake country then I'd say heck no! Two thousand extra pounds of water sloshing back and forth at the end of 12' columns? Oh yeah, that's coming down and you better hope you're not in it!
 

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Along with the other folks replies, remember decks are designed for much higher weight per square foot than regular floors. The reason being, if you have the strength for the tub, don't forget the keg party with all your friends you want to show your new tub to. This is how decks fail. way to many people on a deck asking 1/2 lags bolts in old studs to hold everthing up.
 

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I'd be leery of any deck attached to the ledger with lag bolts instead of carriage bolts. If anything, I'd be inclined to build a set of stairs and put the hot tub on the ground.
 

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The typical deck is designed for approximately 40 pounds per square foot loading. There is no telling what your deck was designed for, if it was designed at all. A hot tub with three feet of water in it will exert about 180 pounds per square foot, which is more than four times what the average deck is designed to carry.

A deck which is designed to support a hot tub must be specially framed to hold up the weight. In some case, if the tub is directly over a post, a deck framed in a conventional manner might be able to hold up the tub. However, no one on an internet chat forum can possibly know if your deck can hold the tub. If you leave your post up long enough, you will certainly get all sorts of answers, ranging from "You will certainly die if you install the tub" to "Don't worry, be happy". What are you going to do with the answers? Average them and decide accordingly? Accept the most pessimistic answer? Accept the most optimistic answer?

I get it that no engineer wants to be bothered with a small job with essentially unlimited liability for a few hundred dollars. I would not do it either. Your building inspector is unlikely to offer an opinion, nothing in it for them except trouble if they tell you to go ahead and the deck collapses with you in the tub. The hot tub manufacturer, if they value their business, will refer you to an engineer to determine if the deck can safely hold up the tub. But you can't find an engineer, so catch 22.

My suggestion is to put the tub on the ground. There is no prescriptive code for designing a deck to hold up a hot tub, so even if you wanted to rebuild the deck to code to hold up the tub, you would need design support. Easier and safer to put the tub on the ground.
 

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Discussion Starter #10
I understand the issues. The balcony is right off our bedroom and above our porch (10-feet). I checked our design from the architect. It was designed to support 50psf. The hot tub company recommended 100psf. Looks like a no go. Thanks
 
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