Introduction: Twin Bunk/Single Bed

Many people with disabilities have issues with muscle tone. Sometimes it is too little - and sometimes it is too much. I have worked with children who have performed incredible feats of destruction because they are far stronger than they know or can control. This project started off as building a replacement bed for some young ladies with Down Syndrome who have absolutely destroyed many prettier (albeit flimsier) store-bought beds. In this case, we are building custom furniture as an accommodation for extra strength and decreased impulse control - no frills, nothing fancy, and as rugged as I can make it.

A side goal is flexibility - to have an mattress frame that would work as a single bed, as well as in a "bunk bed" configuration. This provides future flexibility and means that if at some point a bunk bed is not desired, the beds can be separated and some of it can be reused without having to rebuild everything. I have seen many commercial beds where the single beds can stack into bunk beds, but that connection point is a weak spot given the intended users.

So far, they have not been able to bust through 2x4s and 2x6s used in this. project. These beds are built similar to a deck - the mattress frame is fully supported all the way to the ground (vs. suspended in the air by fasteners).

Everything was modeled in OpenSCAD before building. The cutlists, Bill of Materials, and OpenSCAD model are attached.


The supplies for the bunk bed configuration are:

(14) 2"x6"x96" boards (1.5" x 5.5" x 96" actual dimensions)

(14) 2"x4"x96" boards (1.5" x 3.5" x 96" actual dimensions)

(144) 4" Screws (I personally like torx-head griprite construction screws)

(140) 2.5" Screws (I personally like torx-head griprite construction screws)

(8) 3" Lag Screw + washer


For the single bed configuration:

(5) 2"x6"x96" boards (1.5" x 5.5" x 96" actual dimensions)

(5) 2"x4"x96" boards (1.5" x 3.5" x 96" actual dimensions)

(46) 4" Screws (I personally like torx-head griprite construction screws)

(32) 2.5" Screws (I personally like torx-head griprite construction screws)

(4) 3" Lag Screw + washer

Useful tools:

Paint, Miter Saw, Impact Driver, Router with Roundover bit, Handheld Sander

Step 1: Build the Frame

If we are making a single bed, make one.

If we are making a bunk bed, make two.

A "Twin" size mattress is 38" x 75", so we will make the frame a little bigger to fit up to a 39"x76" mattress - this gives a little wiggle room.

From 2x6 lumber, cut two end-caps at 42" and cut two sides at 76". Make sure the corners are nice and square, then secure the corners with (3) 4" construction screws in each corner.

Cut seven (or more) slats from 2x4 - in this case, 39" wide.

Leave a gap of 4.5" on from the corners and arrange the slats evenly. If you are using the frame in the "single bed" configuration, the leg supports might use the interior corner; and leaving a gap gives space for the legs.

Screw each board into place with (4) 4" construction screws - if using 7 slats, this means 28 screws.

Step 2: Build the Vertical Supports

The vertical supports for the bunkbed use the following parts:
(8) BOARD: 2x6, 75.75" - Vertical Rails

(8) BOARD: 2x4, 14" - Lower Bed Supports

(4) BOARD: 2x4, 35.25" - Upper Bed Support

(20) BOARD: 2x4, 4.25 inches - Ladder Supports

2.5" screws (ladder supports): 40

2.5" screws (upper bed support, every 5 inches): 32

2.5" screws (lower bed supports): 32

4" screws (main uprights, every 5 inches): 64


Screw two vertical rails together at a 90° angle using a construction screw every 5" or so. Screw in (2) 14" 2x4s at the bottom of every support, using (4) 2.5" screws in each 2x4. This will support the lower bed.

Move up 5.5", then do the same with the upper bed support on one side (screw every ~5") and the ladder spacers on the other (measure with a scrap 2x4 to ensure the spacers have 3.5" of space), each held in place with (2) 2.5" screws.

CRITICALLY IMPORTANT - The drawings are of a "right" handed piece. The photo is of a "left" handed piece. For the ladder to work, you have to make two right handed assemblies and two mirrored "left" handed pieces.

Step 3: Assemble the End Frames

You will need:

(8) 2x4 - 39" ladder rungs

(4) vertical assemblies (two left, two right).

Clamp the ladder rungs into place between a "left" and "right" piece.

Secure each rung with (4) 2.5" construction screws, two at each end.


At this point we have two mattress frames and two ladder assemblies. It is time to SAND EVERYTHING (no splinters) and go over all user-facing surfaces (everything but what touches the floor) with a roundover bit and a power sander. 90° edges and corners are SUPER BAD NEWS.

A couple of years ago we were on vacation. My daughter ran into the cabin, tripped over her feet, and smashed her face on a windowsill. Because the unknown person who made the windowsills had the forethought to use a 1/2" roundover bit on the windowsills, my daughter was only bruised. If the edge had been left sharp, that would have been an Emergency Room visit, with stitches at best and loss of an eye at worst. This is a place where little details matter greatly. Always assume that someone will trip and fall and hit your project in the worst possible place. A rounded edge softens an impact considerably. Round the corners and edges!

I see far too many pieces of furniture (made for general use, not even counting for children or for people with special needs) - that is covered in sharp edges and sharp corners. Murphy's law is a thing, gravity is a harsh mistress.... sand down the edges and corners.

Step 5: Paint?

In this case, the client wanted it the brightest, hottest pink we could find.

Paint or sealant goes a long way to keeping the project from absorbing fluids.

Step 6: Assembly

Push a frame into the lower frame slot in one ladder assembly, then fit the other ladder assembly in the other side. Do the same with the top frame.

For this assembly (on site), we used a belt clamp and a ratchet to help pull everything together and make sure the frames are ALL the way in the sockets. Rocking it back and forth and hitting a 2x4" placed over the joints with a hammer helped everything to wiggle into place. Always remember that paint adds a thickness to parts. :-)

Once everything is snug and tight and square and flush, we inserted a 3" lag screw (with a washer) through the vertical rail and into the mattress frame (4 per mattress frame, 8 in total).

Cut a Safety Rail at:

(1) - 2x4 - 79" - Safety Rail

and screw into the top supports using (4) 2.5" construction screws. If needed, another safety rail could be added on the short side; although in practice this does not seem to be needed; the extra height of the vertical rails helps serve as a handle to make entry and exit from the top bunk easier.

For extra points, screw a right-angle bracket into the top mattress frame and then into a wall stud to prevent the bed from being tipped over. Tipping would not be accidental - this bed is extremely heavy and does not move at all if an adult hangs on the side - but it is still a good safety measure.

Step 7: Single Bed Variation

If using a single bed version, the frame is the same, the only thing that we need is the feet.

Make four of the legs shown using these parts:

(8) 2x6, 19.5 inches - Outside support

(8) BOARD: 2x4, 14 inches - Support under the frame

4" screws: 16

2.5" screws: 32

Screw the 2x6 pieces together at a right angle, using (4) longer screws for each, then attach (2) 2x4s at right angles and screw into the 2x6s using (4) 2.5" screws for each piece of wood.

Again, you will need to make two left-handed versions and two right-handed versions of the leg. The drawing above is a right-handed part.

The photo shows a "Single" bed using a similar model of leg (the legs in the photo are inside and under, vs. outside and under in the drawing). This was an earlier model, and I changed the later model to legs outside and under the corners,

Secure Legs to Frame with (4) 3" lag screws, as before.