How to Build a Playroom Loft Above a Children's Bedroom With Stairs or a Ladder

Measuring, Cutting and Framing the Loft Platform

• 1

  Measure the floor-to-ceiling height of the room and record. Use this as a factor to decide at what height you want your loft, along with the age of the children and the intended activities. The higher your ceiling, the higher the loft floor can be, although you need a minimum of 36 inches even for younger children to read or watch television, for example.

• 2

  Mark the height, length and width of the loft floor along the walls where it will attach. Repeat at least once per wall and run a straightedge between marks to create a guide. Consider making the loft span the full length of a wall, if possible, to utilize as much wall framing on three sides as possible. While your loft can stand free of the wall, technically -- for an easy-to-disassemble-and-move item -- anchoring it to the studs in the wall provides extra stability and safety.

• 3

  Cut four posts from untreated 4-by-4-inch boards. Use the height of the loft floor, minus the thickness of the loft flooring used -- either 3/4-inch or 1-inch-thick plywood -- when measuring. Once assembled, the posts will nestle under the floor and inside the loft framing boards, so allowing for the floor thickness is critical to obtaining the precise loft floor height you desire.

• 4

  Measure and cut two 2-by-8-inch boards to reflect the width of the loft desired and another two the length of the loft minus 1 1/2 inches. These are the loft's outer frame boards. Subtracting 1 1/2 inches allows the width boards to overlap the length boards in a butt joint.

• 5

  Cut additional boards, using 2-by-6-inch-thick lumber, to provide support framing inside the loft frame, much like floor joists in a floor. Make one board per 12 to 16 inches of loft length. Use wider boards, for either the outer framing or support framing, for heavy-duty construction. Make each board 3 inches less than the width of the loft to allow it to fit between the frame boards.

• 6

  Assemble the loft floor, laying each of the outer frame boards on edge with the widest face running vertically. Overlap the long ends with the boards running widthwise. Drive wood screws through the shorter boards, into the ends of the long boards, three per side.

• 7

  Set a frame support board inside the outer frame boards, positioned with one board for every 12 to 16 inches in length. Ensure that the edge of the board is flush with the edge of the outer frame; any variance will cause problems when installing the flooring. Attach with wood screws, driving two or three per end through the outer frame into the support board ends.

• 8

  Cut a sheet of plywood to fit the width and length of the loft precisely. Lay the board on top of the loft floor frame, ensuring the side where the support boards are flush with the outer board supports the plywood. Secure with screws, driven down through the plywood into both the outer frame boards as well as into the support frame boards, every 6 to 8 inches.

• 9

  Flip the frame upside down to expose the underside. Fit a post inside each corner, snug to the outer boards. Use screws to attach the frame to the post, two or three for each side of the frame. When each has been secured, turn the frame right side up and drive additional screws down, through the plywood, into the top of the post. Thus, each post is attached to the loft floor on two sides and again on the top.

Completing the Loft

• 10

  Find the studs in the wall framing wherever the loft guide previously marked runs. Use a stud finder or tap on the wall to find where it sounds and feels solid rather than hollow. By definition, studs should be 16 to at most 24 inches apart in modern homes. Mark a long line vertically to identify the studs.

• 11

  Stand the loft up along the wall. Check that each post is flat against the floor and the platform itself is snug against the wall. Drive 6-inch-long lag bolts through the posts into the wall framing every 12 inches vertically as well as through the platform framing, into the studs, whenever encountered.

• 12

  Cut two 2-by-4-inch boards to create a top plate and bottom plate for any rails needed. The entire loft, less about 24 inches for the stairs opening, should be enclosed with rails. Thus, take the lengths needed and cut the boards accordingly. Use smaller boards -- 1-by-2-inch at minimum -- for railing if space is limited.

• 13

  Measure and cut additional rail boards to run between the rail plates, one every four or five inches. Make these the height desired; for rails running up to and anchoring to the ceiling, measure the ceiling to loft platform and subtract twice the board thickness to fit. Ensure your railing is high enough to protect children from accidentally falling out -- generally at least 12 to 18 inches.

• 14

  Construct the railing, sandwiching the rails between the plates and attaching with screws, driven through the plates into the rail ends. Secure each rail section, flush with the edge of the loft, using additional screws driven through the platform as well as into the wall or ceiling, as appropriate. Attach end rails to side rails if applicable.

• 15

  Measure from the floor of the loft down to the bedroom floor. Divide the result, in inches, by seven to determine the number of steps needed for the ladder. Then divide the height by the number of steps. The result is the rise measurement needed -- the distance from one step to the next.

• 16

  Multiply the number of steps by 11 -- the step depth, called a run -- to find the distance the stairs will extend out from the loft. Picture the height of the loft as one leg of a right triangle and the distance extended as the base leg of the same triangle. Find the hypotenuse -- the length of the stair stringer needed -- by applying the Pythagorean Theorem: square the total rise and square the total run. Add both together; take the square root. Test for adequate clearance before cutting the stringer to length; increase the step rise or shorten the run slightly to create a shorter stringer, which will not extend as far into the room.

• 17

  Clamp a straightedge to a large carpenter's square, aligned with the rise measurement on one side and the run on the other. Allow the square to overhang a 2-by-10 board with the straightedge gliding along the edge. Starting at one end of the stringer, trace around the square leg indicating the rise, then around the leg showing the run. Slide down and repeat. When finished, this creates a zigzagging pattern like teeth on a saw blade.

• 18

  Cut the stringer out, using a circular or jig saw to cut out the bulk of each cut but switching to a hand saw in the inner portion of each cut. Avoid cutting past the guide, into the stringer, which weakens it significantly. Use the first, finished stringer as a template to outline and cut the second. Square the bottoms of the stringers, cutting off 2 inches to account for the thickness of the thread and allow the stringers to rest flat against the floor.

• 19

  Attach the stringers on either side of the opening left between the rails. Use screws to attach to the wood framing. Run 2-by-4s, or wider boards, as desired, across the tread area of each step. Drive screws through the boards into the stringer to attach. Enclose the backs of the steps, called risers, similarly if chosen.

• 20

  Cut a hole in the plywood platform of the loft, making it the width of the support framing and about the same depth. Frame the opening with boards screwed between the support boards. Add hinges to the removed section of flooring and secure to the platform to create a hinged trap door.

• 21

  Create a rope ladder by drilling 3/4-inch-diameter holes through either end of 1-by-4-inch boards or desired material. String 3/4 inch nylon rope through the boards, one on either end, tying the rope after each board to secure it in place. Space the boards, which become rungs, every 8 to 10 inches. Attach the finished rope ladder to the loft with eye bolts or by drilling additional holes in the platform framing and knotting the free end of the ladder on the other side of the hole.