How to Build a Low-Level Deck for a Hot Tub

Measure the height from the ground to the top of the hot tub, using a tape measure. Add 12 inches to this measurement to find the length of the support posts you will need. Measure the length and width of the hot tub. Add 24 inches to the length and width measurements. Note all these measurements on a sheet of paper.

Cut 16 pieces of two-by-four lumber to the support post length, using a circular saw. Varnish the posts using exterior grade varnish and a paintbrush. Cut 12 pieces of two-by-four to the length measurement and 12 pieces to the width measurement. Cut the length measurement pieces in half. Cut the width measurement pieces in half.

Measure 12 inches across the ground from the middle of each side of the hot tub. Mark these points with chalk. Mark out on the ground a square around the hot tub with sides touching these marked points. Dig a hole 12 inches deep at the corners of the square and in the middle of each side of the square, using a spade. Dig a hole 12 inches deep at each corner of the hot tub and in the middle of each side of the hot tub.

Mix a batch of concrete using 1 part cement, 3 parts sand and 1 part water. Plant one of the support posts in each hole you just dug. Fill around the posts with cement. Wait 48 hours for the cement to set before continuing. Measure the distance between the outer middle support posts and the outer corner posts. Repeat for the inner distances. Cut the length and width pieces to these measurements.

Screw half of the length-measurement pieces between the corner and middle posts on inner and outer lengthwise sides of the hot tub, at ground level, using 6-inch long screws screwed diagonally into the pieces. Screw an L-bracket onto the top of the horizontal pieces to reinforce the joint. Screw the width-long pieces between the support posts on the width-long sides of the hot tub in the same manner. Repeat with the pieces at the top of the posts.

Cut 10 one-by-two inch beams as long as the width of the frame. Screw one beam across the inside of the top of the frame on both width-long sides, using countersunk 2-inch long screws. Screw another beam across the outside of the top of the frame in the same manner. Screw three beams in between the inside and outside beam on each side of the frame, to cover the width-long sides with supports.

Measure the distance along the lengthwise sides of the frame between each of the innermost support beams on the width-long sides. Divide the measurement by four to find the number of support beams for each side of the frame.

Measure the distance from the edge of the hot tub to the outside edge of the frame on the lengthwise sides of the frame. Cut as many pieces of one-by-two lumber to this length as you calculated needing to make support beams. Screw the beams across the lengthwise sides of the frame with a 2-inch gap between each beam.

Cut strips of decking as long as the length of the frame, using a circular saw. Lay decking against the edges of the hot tub on the lengthwise sides of the frame. Screw the decking to the support posts using countersunk 1-inch long screws. Screw decking to the rest of the lengthwise sides, keeping each piece flush with the previous piece, to form a solid deck.

Measure the distance from the outermost edge of one of the widthwise cross-pieces on the outside of the frame, to the innermost edge of the widthwise cross-piece on the inside of the frame. Cut decking slats to this length using the circular saw. Screw the slats on top of the width-long sides of the deck frame using countersunk 1-inch long screws. The end slats should be snug with the edges of the lengthwise decking.