How to Frame a Tub Wall

Measure and mark the wall location on the floor. Plan the wall only after you have the tub you are installing and make the wall exactly 1/8 inch away from the tub when properly situated. This may involve measuring over from an existing wall to the length of the tub plus 1/8 inch for a wall at the head or foot of the tub, but the same gap is necessary along the length as well. The 1/8-inch gap around the tub allows for expansion and contraction without cracking the wall surface or creating instability.

Cut two 2-by-4-inch boards to the length of the wall desired. Lay the boards, which are the top and bottom wall plates, flush with the widest face up. Make a mark 1 1/4 inch from the edge of the boards, again at 15 1/4 and every 16 inches thereafter as needed. Mark the plates 1 1/2 inch from the end even if the space is less than 16 inches. Use a carpenter's square to mark this stud spacing on both boards at once. Reduce the stud spacing to 12 inches if desired; any less won't provide adequate plumbing room.

Find the floor-to-ceiling height. Subtract 3 1/4 inches, the combined thickness of the plates plus 1/4-inch clearance, from the height to find the stud length needed. Cut enough 2-by-4-inch boards to match the number of stud marks on one plate.

Construct the wall, attaching each stud flush with a stud mark. Nail through the first plate, into the stud ends, with two 16d nails. Stagger the nails slightly to prevent splitting the wood. Attach the remaining plate similarly to the free ends of the studs.

Cut additional 2-by-4-inch boards into short blocks that fit between the studs snugly. Nail them in place, flush with the wall surface, driving the nails at an angle through the blocks into the studs. Base the installation height on your needs Just above the top edge of the tub, when it sets in position, helps reinforce the immediate surrounding as well as providing support for soap dishes and such. Other heights may prove more convenient for tub seats, hand bars or accessories. In addition, two blocks, flush against the rear of the studs, provide support for any plumbing necessary inside the wall.

Bore holes, using a hole saw, through the bottom wall plate to allow plumbing lines entry into the wall, if applicable. Base the location and size on the plumbing used.

Situate the wall as indicated by the floor guide lines. Hold a level against the stud surface to determine the wall is plumb, meaning straight up and down. Adjust as needed, then push wood shims under the plate to fill the 1/4-inch gap created for clearance. Nail through the base plate into the floor joists and through the top plate into the ceiling joists. Secure to any adjacent walls.