How to Build a Whirlpool Tub Deck

Measure the height of your whirlpool tub and the depth from the front to the back of the tub. Side to side doesn’t matter because the tub frame will be built according to the tub space that was provided in the framing for the bathroom. Instead of measuring the length of the tub, measure the distance from wall to wall where the tub will be installed. Use these measurements for your cutting.

Cut down the pieces of 2-by-4 material you need to build the frame using a miter saw. For the horizontal pieces of the frame, you need four of everything: two matching pieces for the bottom of the frame along the front and back and two more pairs that are according to the depth of the tub (the sides).

Make an appropriate number of vertical pieces to use as the studs for the frame. These should be placed 16 inches apart from each other, so make an appropriate number according to the dimensions of your tub frame. Cut these pieces to the actual height of the tub; the bottom and top pieces of the frame will add an extra 4 inches of overall height.

Mount the bottom pieces of the frame onto the subfloor by screwing them down with the drill and 3-inch wood screws. Use the level to help guide the installation of the vertical pieces so they are plumb. Screw them in at an angle into the bottom frame pieces, into the wall studs and along the sides and back. This will provide extra support and tie in the installation to the house.

Screw on your top pieces of the frame to the vertical supports with the drill and 3-inch wood screws. Drill straight down into the vertical studs along the front section of the tub frame. Add extra screws angled in from the top into the wall studs so you have more support.

Measure the overall frame size for the top and cover it with a piece of plywood. Cut the piece of plywood down with a circular saw. Apply some construction adhesive to the top of the frame to act as a bond between the plywood sheet and the frame. Screw the sheet into place with the shorter screws and then mark the top with template provided by your tub manufacturer. Cut out the hole with a jigsaw to make room for the tub.