Hot tubs are installed on a variety of surfaces, including concrete slabs, gravel and the ground. No matter which of these bases you choose, the first step is to properly level the ground the hot tub will sit on. If the ground is not perfectly level, the water level will be slanted once the hot tub is filled. Levelling the ground is a labour-intensive process but reduces future problems with your hot tub.
Determine the measurements of your hot tub by examining the installation instructions or by measuring it with a tape measure. Transfer the measurements onto the desired ground location using spray chalk to create the outline.
Dig out the top 1 to 2 inches of soil using a shovel, staying within the perimeter of the chalk line. Place the removed soil into a wheelbarrow and transport it to a compost pile or another area of the yard.
Locate a wooden board that is the width of the area within the chalk line. If needed, secure two boards together using wood screws.
Fill the area with coarse sand until it is flush with the rest of the ground, and smooth it out as evenly as possible using the shovel.
Walk to one side of the pit and place the board on the ground. Push the board all the way across the sand to level it off. Then, place a level on top of the board and ensure the air bubble is centred. If not, determine which area of the soil is higher, and dig it out using a shovel or hand spade.
Move the level to a new section of the board and repeat the process to determine if the soil under it is level. Dig out additional soil if needed. Continue until you reach the opposite end of the board.
Shift the board to a new location on the ground and repeat the process to level the soil under it. Continue using this method until all of the ground is level.
Place the plate end of a hand tamper tool on the inside bottom of the pit and hit the ground with it repeatedly to pack down the sand tightly. Continue tamping the soil all the way around the perimeter of the installation area.
If you are constructing a gravel base for the hot tub, dig down 12 to 18 inches before levelling the ground.