A hot tub deck must be able to support the weight of a hot tub, which is a considerably large load. The hot tub deck must therefore be carefully constructed and supported properly by blocks and beams secured in the ground. Before building a hot tub deck, however, the builder must consider a few factors: first, do I need a building permit? Second, is the deck going to be built close enough to the proper power supply? And third, how is the hot tub going to be placed on the deck? This last question may affect the height and location of the deck within a yard.
Once the location of the hot tub deck has been determined, it is time to begin building. The first consideration is size: an 8 foot by 8 foot (2.4 meter by 2.4 meter) square deck will accommodate most hot tubs. To build such a hot tub deck, a perfect square must be determined. Pound stakes into the corners of the square, then determine the center point of the square. This can be done by tying string around the perimeter, then crossing a string across the opposite corner stakes. These stakes and the center stake will be the location of the concrete feet, as well as the centers between the corner stakes. Nine supports in all will be used.
Dig holes at the stakes. This is where the concrete supports will be placed. The builder can pour concrete feet or buy pre-formed ones. If pouring concrete, the vertical beams can be added directly to the concrete, but they must be steadied at level. Pre-formed concrete blocks will have metal tabs that the beams can be affixed to. Sand should be lain beneath the feet for support and leveling.
Once the feet are lain and the holes filled with earth for support, put the center post onto the center block. Measure the height, and cut the other posts to the same height. Lay those posts, then lay a beam across to make sure they are level. Once the level has been determined, secure the beam to the posts and the posts to the blocks. Repeat this process with the outer posts and beams. At this point, measure the diagonals to ensure the proper positioning of the beams.
Secure all beams together using beam ties and nails. Then secure a 2 x 6 (.6 x 1.8m) board by "toenailing" it to the tops of the beams, perpendicular to the beams. Repeat this process with four 2 x 6 boards across the beams. Add another board to the ends of the toenailed boards to box them in. Add deck boards to the top of the boards to provide the top surface where the hot tub will sit.