Anyone have a Grandee on a Deck

[TimC]

Looking at the Grandee over a Vanguard, but am wondering if the extra weight is risky on a wood Deck.

[Brewman]

Depends entirely on your decks ability to support the weight.  That in turn is determined by the structure of the deck itself- adequate footings, beam, joist and decking.  Someone in your city building department might be able to help you determine your decks load capacity.  You'd also need the weight of the filled spa, and the size of it's footprint.
Brewman

[Chas]

I have put quite a few of our larger tubs on wooden decks with good results.

If your deck is built to standard floor specs, it should hold the tub just fine, but it will most likely sag over a period of years. What to look for: joists on 16 inch centers, not 24 inch centers, and that the span of the joists doesn't exceed standard building practices: that is, about one foot per inch (a 2x8 spans less than 8 feet, a 2x10 less than 10 feet etc).

To keep from having trouble down the road, a couple of extra peir and post combinations can be added near the center of the tub - with a 4x4 or 4x6 beam between them. This can be a very simple addition if you can get under the deck -  you will have to tear off a couple of deck boards and do it from the top if you can't get under.

If you just can't do the peir/post part because of limited access, you can simply double up a couple of the joists or a beam under the spa.

A final idea: if you can't get under your deck at all, and it has less than standard construction, you can build a new section of deck on top: going from existing post to post, but overbuilding. This can also be done by simply taking out the section of deck that will be under the spa and rebuilding just that section, keeping in mind that the tub will cover your work so it doesn't end up looking bad.

[empolgation]

Brewman is right on.

There is no problem putting a tub on wood deck - it just has to be built to support it.

Typical residential decks are built for a live load of 40 to 60 pounds per square foot (psf). A full hot tub is going to exceed that pretty quickly. Many building departments require/recommend decks support a live load of 110 to 150 psf for a tub - but that of course will depend on the size of the tub. You should have someone qualified help you to determine what improvements, if any, are required of your deck to support your tub.

[TimC]

Ok, so what do you think

Deck is basically a 10X10 extension of a much larger deck.

Joists are 16 inches on center.

Originally the joists were supported by the a double 2X8 at the 7 foot mark and then hanger supported at the house into the Ledger(?) board.

I have sence installed three additional supports on Deck Blocks between each joist with a 2X4 support (very low clearance).

So now under the tub there are 3 - 2X4 supports on Deck blocks spaced 16 inches appart and then there are the existing 2 additional supports one at the house and the other at the end.

Seems like it should hold a ton, but then again it needs to hold a little over 3 tons.