How to Build a Floating Deck





Introduction: How to Build a Floating Deck

About: "Inaction breeds doubt and fear. Action breeds confidence and courage. If you want to conquer fear, do not sit home and think about it. Go out and get busy." "La inacción engendra la duda y el miedo. La ac...

Here I will show you how I made a floating deck. The advantage of a floating deck is that it is possible to be moved to any location in the yard. This is by no mean a new Instructable, it was done before by TimBTodd. The deck that we built is 12'x12' and is supported by concrete deck piers.

Step 1: Materials

8 - 2x4x12 treated studs

30 - 5/4 x 6 x 12 treated lumber

10 - concrete deck piers minimum

2x4 stud steel reinforcements

Galvanized 3 1/2'' nails.

Extra cinder blocks and bricks to level the footing.

Step 2: Building Your Deck

I started by nailing four studs temporarily together to make a square. Then I nailed the other studs to the frame I made using the metal reinforcements. I used a square to make sure that every stud was parallel to each other. When the frame has been completed we moved the frame where the piers were.
The ground that we picked for our floating deck was uneven so I had to play a little with cinder blocks and bricks to level the frame. Once I was finished with levering the frame I could start nailing the planks to the frame.
We left some spacing between planks to allow for expansion during hot and humid days and for rain water to filter through.

Step 3: Finished Project!

Our finished project, ready to serv us this summer.



    • Casting Contest

      Casting Contest
    • Oil Contest

      Oil Contest
    • Make it Move Contest

      Make it Move Contest

    We have a be nice policy.
    Please be positive and constructive.




    This is a big help. Thank you for posting!!

    Can this be done if the ground is sloped? If yes, how would you level the deck as all of the deck piers are the same size? Would you have to dig a hole to set some of the piers into where the ground is higher? Would this cause issues with ventilation?

    We have an area against the back of our house that we wanted to build either a raised patio with pavers or lay concrete, but we have too many electrical/cable/phone lines that come into that area to be able to dig deep enough. We also cannot add dirt as there is a door to a utility closet. Just wondering if a floating deck might be an option since we wouldn't attach a deck to our foundation.

    2 replies

    To make it work in a sloped area you would need to place different lengths of "feet" from the deck frame to the concrete piers. This is what I did in my backyard.

    You don't need to attach a deck to your house's foundation. It is known as a "free standing deck" and you use treated 4x4's posts cemented to the ground. You need to install the posts first, then with a chalk line level and later cut the posts. Lowes has a deck designer browser program that allows you to design your deck and calculate how many materials you are going to need.

    It depends. If you are going to use it for an inflatable pool, the weight of the water leaning on one side of the pool walls will end in disaster.

    What I mean is our back yard has a slope

    Could this be built to place an above ground pool on? our backyard has a slope and this seems easier than trying to level the ground where we do not plan to permanently reside. the size of the pool is 16x48

    1 reply

    You need to consider the weight of the pool with the water. It might be better to level the ground.

    Does this deck sway a lot? 
    8' is a really long distance to span a 2x4.

    3 replies

    8 feet for 2x4's is fine for a project like this. You could go to 10 feet as well, but that's pushing it with 2x4's. I am building a similar design deck, and am using 2x6's because of the length spanned, 15-20 feet. Because it is "on grade" (not elevated) the twisting won't be as severe. If I was going above grade or with elevations, you would want 2x8 or 2x10. 8 feet for this purpose is fine. As added piece of mind, you could use joist hangars. Additionally, your rim joists (the outside frame) could be 2x6's with carriage bolts. However, that might be considered over-building for a project like this.

    Not a t all! It is very sturdy.

    I was wondering if a deck 16' x 15' , 5' above the ground could be built as a floating deck. The reason for asking is that someone said it would allow the snow and water to run under the deck where it meets the house where it is attached to the house. My question is what about the ledger board. This is where the person was thinking of the rot that would occur under the sideing and between the house and the deck. What would the joist be attached to for strength and the sona tubes would they go near the house?

    The comments here are a little confusing. I think someone is expecting to anchor boats to this???

    It's not that kind of deck. I built mine on a slope next to the house. It is supported by pieces of 4x4 treated lumber standing vertically in the deckblocks. I had my doubts, but it ended up being incredibly stable. The longest vertical length I used was 30 inches.

    You do NOT attach this TO a house, although it can be right next to a house. The deck will shift up & down a little with the seasons. Your house does not because of the foundation. Moving object connected to non-moving object=problems.

    The deck block website has great install info and a DESIGNER program. Tell it what size deck you are building, and it gives you plans and a lumber list.

    could you use the piers and 4x4's to raise this deck say 7 feet, of course diagonal bracing would be necessary or would concrete footers be the safer way to go here?

    can a floating deck be made above ground so it is not joined to the house. I've heard attaching the ledger board allows the water to rot the frame under the sideing and also the snow collects under the deck where it meets the house over the ledger board, where as if it's floating all water and snow just passes down under the deck

    1 reply

    About your question, it is possible to build a deck without joining it to the house and it is known as a "free standing deck". As long as you use pressure treated lumber you do not have to worry about rotting wood. A "floating deck" is not attached to the house and you can move it anywhere on your yard. However you could build a "free standing deck" next to your house but it will be a permanent structure supported by many 4x4 studs. With a "free standing deck" you do not need to cut into the siding. That seems to be your concern, right? Tell me how your project is going and do an 'ible about it! I wish you the best!

    The floating deck I was asking about is a 16' x 15' and 5' above ground.

    I thought that "a deck" referred to maritime matters : a floating deck should obviously be built with floating devices that help it float on water and be boarded by boats ?…

    Or did I miss something ?…

    1 reply

    i see the word "floating deck" used a lot on diy websites floating refers to the fact that it is not joined to the ground like most decks(patio) by burying 4x4s and pouring cement in the holes. sorry don't know the exact tems used to describe things, not in the construction trade