How to Support a Hot Tub on a Raised Deck

Locate exact points under the deck to place 8-inch-square post material made of pressure-treated lumber. Choose the placement of posts based partially on visual appeal to ensure the spacing looks appropriate from every angle. Be sure to install a support post for general support under every third or fourth deck floor joist, for example.

Install a support post underneath deck flooring at all four corners of the hot tub, regardless of other deck support placement. Add support in these areas to ensure the safety of the occupants in the hot tub. Plan to hide the posts from yard view via decorative lattice or plantings, if needed.

Locate ground-level dimensions for concrete footings 12 inches square each. Build concrete pads to support posts after carefully defining placement of these footer forms, so they'll each sit under the decking in the right footprint. Drop a plumb bob to define the center of each square you will construct.

Dig down to solid soil to build the footings below the frost line in your area. Remove dirt with a small shovel to install the wooden forms. Cut 1-by-4-inch boards held in place by 10-inch stakes around the pad's perimeter. Make the cuts for all the separate form pieces using a circular saw. Pour concrete in each form and trowel to a smooth finish. Mix your own concrete from a bag if you have ten posts or less. Call a concrete delivery truck, as a time-saver, if you have many posts to support.

Cut each post to the precise length needed with a circular saw. Measure the exact height needed to within 1/8 inch by checking the height between the concrete pad and the floor joist above it. Push each post into place and tamp gently with a sledgehammer, if needed. Position each post in the exact center of a joist, allowing for visual appeal from every angle.

Fasten a steel post sleeve attaching the support post to a deck joint. Purchase a cradle-type sleeve or a retrofitted metal connector that you will use to join the post and beam with either 4-inch screws or 12d nails, gauging the size of the screws or nails by the diameter of the pre-drilled holes in the metal.

Paint or stain the posts to help preserve them. Choose a color that harmonizes with your home's colors. Cover the front and sides of the decking with lattice if the posts are too visible to blend in with your home's design. Select crisscross lattice for a more casual look, but install window-pane lattice with horizontal and vertical pieces to look more formal -- especially if your deck is visible from the front curbside of your home.