Measure the width of the hot tub's access panel (Image 1). This will be the width of the access panel door. Cut several 2x4 beams to the width of the access panel. Lay the beams next to each other and make sure they are flush along the edges. Then, screw two 2x4s across the beams to keep them together. Once the access panel door is screwed together, set it in place in front of the hot tub access panel (Image 2).
Begin nailing 2x4 pressure-treated beams across the frame of the deck. Since the corners of the hot tub are rounded, use a jigsaw to cut a radius into the pieces of wood that will fit up against the hot tub's corners. Once it's determined that they fit around the hot tub, nail the boards into place. Continue nailing 2x4s into place until the deck is finished.
Remove the access panel and the access panel door. Connect PVC pipes from the base of the hot tub to the nearby water heater. Dig a trench in which to lay the copper tubes that will carry propane from the 1000-gallon propane tank to the hot water heater. Connect the copper tubes to the hot water heater.