Case #662, titled “Digger” has a Mr. Conrad W. Crete, his close buddies refer to him as “Con” or “CW”, looking to extend his existing backyard deck by another six feet.
His present deck spans the width of the home, but only extends out about 10 feet, which up to this point, has provided plenty of sitting and lounging space.
However, with a just purchased hot tub on the way, measuring about eigh ft. in diameter, the existing 10 foot depth allowance is going to be eaten up pretty quickly. Plus, C dub’ya wants to access his hot tub comfortably from all sides, which would require a new deck depth of at least 16 feet.
Mr. Crete’s present deck is of standard wood construction, complete with a ledger board attached to the home’s foundation, and four poured concrete piers, which support a beam and the balance of the joists system. At issue is the fact ‘Con’ wants to simply attach this deck extension to his existing deck, using deck blocks to support this new framework. In essence, he wants to attach a floating deck to a poured concrete pier deck.
Adding more challenge to the situation is the fact Mr. Crete is hoping to simply butt this new piece of framework up against the existing series of joists, enabling him to make a seamless transition from old surface decking to new.
In theory, and if all things could remain as dry and as warm as the day of assembly, then a floating deck attached to a permanent structure could possibly work. However, that’s not going to happen. Once the rain and snow melt seep through the floor boards, and/or the water runoff from the downspouts surround the deck blocks, with this dampening of the soil either causing the blocks to sink slightly, or heave up a little during the colder months, you’ll be able to sell tickets to school children by having them experience your crooked deck exhibition. Floating decks and permanent structures (such as a deck supported by piers, or your home) are like the Toronto Maple Leafs and the Stanley Cup. They’re fine apart, but never the two shall meet.
A floating deck can provide a good surface to live and play on, but because it’s susceptible to whatever ground forces lie underneath, it’s got to work independently. So, a floating deck can butt up to a home, or existing deck, which would allow you to make various adjustments to this deck if necessary, but it should never be attached.
C dub’ya really wanted to float this deck addition, since the thought of mixing cement was about as enticing as attending a 6 a.m. outdoor yoga class. The challenge would be in maintaining a seamless transition between existing deck structure and floating deck, since the floating deck is most likely to move a little bit, whereby even a one-quart to one-half inch of difference would create a dangerous trip hazard. It was then suggested to Con that he add 16 feet of floating deck, positioning it one step lower than his existing deck, creating a second tier (which would look quite attractive) while solving the issue of having to maintain a perfect seam, or transition, between the two surfaces.
This suggestion was quashed. Con and his wife Babette enjoy winter hot-tubbing, where C dub’ya felt the 10 ft. sprint between patio door and hot tub, dressed only in his bathrobe, at any point below 10 degrees Celsius, would result in shrinkage significant enough to affect the intimacy.
So, it looks like we’re digging. Because we’re elongating an existing deck, the support beams already in position were simply made about six feet longer, and would be supported by a second series of poured concrete piers. Additional lumber was then added to the existing piers, in order to help them support the connection between new and existing beams.
Case #662 closed. Good building.