DIY Built-in Quad Bunk Bed | Part 1: Bones and Boxes
Before we moved into this house in May I promised the girls I would build them an awesome bunk bed setup. It is time I deliver on that promise.
This post is part of a paid partnership with the Home Depot and contains affiliate links.
I just released Part 1 of the series over on my YouTube channel but I wanted to share it with my readers as well. If you want to watch the video I have linked it below.
The Bunk Bed Bones
Let’s just jump in- I started the build by cutting 4 2x4s the entire width of the bunk beds. I also cut 8 2x4s the width of the mattresses. These 2x4s will make up the structural frame of the beds. I also cut two 2x4s to the height of my ceiling, these are going to function as posts for the middle of the bed.
I marked the studs on the wall ahead of time to speed up installation and then got to assembling. Each horizontal frame piece is attached with 3 3 ¼ screws before mounting it on the wall. You could replace these screws with joist hangers to add strength and simplify this build, but I prefer this cleaner look. Then the 2×4 plates are installed into the studs using 3” lag bolts.
These subassemblies are large and unwieldy so do what you can to assemble them in place if possible. Once I mounted the top bunk to the wall, it made a decent impromptu workbench for assembling the bottom bunk, using top bunk as a giant story stick. Once again the bottom bunk was installed into the studs using 3” lag bolts.
On-Wall Installation
Now its time to install those 2x4s that were cut to the height of the ceiling. These fit into the channel I left between what would become the headboards of the two beds. The total width of my bunk beds is 13’ 3”. If you have a little more space, it would be better to install these columns parallel with the bed rails for added strength. Either way, this thing is like the Rock of Gibraltar.
After installing the posts with screws, the sandwich can now be completed with the outer bed rail. I attached this from the outside with 3 ¼” screws, quadruple checking that everything is still level. This framing is the backbone of the bunk bed structure. If you screw anything up it will be compounded and give you headaches later in the build. In other words, take your time.
For the inner bed rails, I ripped down a few 2x4s and screwed them into the structural rails. This is a critical failure point for the bed so you may want to add glue to these joints.
I chose to use ½” plywood for the bases of the beds, which might be a little springy for some, but it is more than strong enough for these beds. If you wanted something stiffer you could use 3×4” plywood, or if your kids are hot sleepers you might consider slats to allow air to circulate under the mattress.
I cut my plywood to size and dropped it in. I also added a 2×4 furring to the front faces of each of the posts to nail my trim boards into. It is also at this point, of course, time for a strength test. Honestly, add some simple rails and ladders from here and your kids will be happy. The novelty of sleeping up high will outweigh any fancy touches you could ever come up with.
But that doesn’t mean we’re not going to try. The next step is going to be covering up all of that 2×4 framing with some clean smooth 3×4” MDF. I used a track saw to rip this into 8” strips and measured and cut them all to length. It is important to measure the actual dimensions in the room before cutting because walls are rarely square and, even if they are, they may have a slight bow from installation.
I started from the center and worked my way out. I used a cut piece of MDF cutoff to give myself the proper spacing on the rail facia so I could come back and add the top piece without any fuss. Each piece of MDF was attached with several 1 ¾” brads without glue. If you wanted to build something like this even more permanently, you could add construction adhesive to the MDF before sticking it on. Honestly, that just sounds like more work when the girls grow out of this thing in 5-8 years.
Bunk Bed Boxes
With the facia now installed, I went back to the shop to assemble the boxes that would cover the columns. It is very important when working with MDF to predrill and countersink all of your holes before assembling with screws. MDF is going to mushroom on you if you try to drive in even the best self-tapping screw, and that is no bueno.
If you measured and assembled everything carefully you’ll end up with a pretty snug fit. I then installed the front boxes with countersunk screws through the facia.
The other side of the box and the headboard is going to be a little more complicated, so let’s measure carefully for these and go back to the shop so I can walk you through it.
Headboard
I started by building a headboard that was just the right width to fit between the two boxes and whatever height you want. I positioned the headboard on top of the box and predrilled a few holes through the inside of the box using a collet extension on my drill. Then I removed the headboard and completed predrilling the holes to avoid the aforementioned mushrooming.
I then repositioned the headboard onto the box and gave the box a little bit of counterweight so I could hang the headboard over the edge of my workbench. In this case, was my table saw, don’t judge. In other news, workbench build coming very soon.
This is where the unexpected hero of this bunk bed build came into place, rapid setting Cyanoacrylate (CA) glue. I used a couple of different kinds throughout this build but my current favorite CA glue is Starbond Thick and the rapid cure aerosol. Its got just the right consistency for these fiddly kludges that always seem to happen in woodworking.
To be clear I used CA glue to clamp the pieces in place so I could then follow up with screws into the predrilled holes for a stronger connection. Then I screwed the box and headboard into the post and toe-nailed it into the other side.
With all of the trim boards, or facia, whatever we’re calling it installed, it was time to get the whole thing cleaned up and ready for paint. I set all the brad nails that weren’t sunk beneath the surface of the MDF then filled all of them along with the countersunk screws with two-part Bondo wood filler. This stuff sets up fast and is a little tough to work with, but it is really the best filler for MDF or plywood when prepping for paint.
After Bondo-ing my little heart out, I sanded everything flush with 80 grit sandpaper and added some round overs with Makita’s cordless router with a ¼’ round over bit to make sure those kids wouldn’t hurt their pretty little heads.
I went with a ¼’ round over bit so my lines stayed pretty clean, but you could use a larger radius round-over bit if you wanted a smoother transition or a chamfer bit if you wanted a harder edge. MDF does need some sort of edge treatment before painting or it is going to get messed up.
Now its just time to prime and paint and we’re on to Phase 2 of the bunk bed build.
Must-Have Tools
I want to call out a few all-star tools from this build.
They had the power to meet every need in this project and kept on ticking. Also, THAT BATTERY LIFE. I drilled countless holes, countersinks, drove lags, cabinet screws, and the like and I was only down one notch of battery life from this whole project. These are going on my tool wall Mt. Rushmore FOR SURE.
If you want to pick them up, you can get them from Home Depot at the below link
Makita LXT sub-compact impact drill and driver
This all-aluminum 7” speed square has all of the clever little scribe holes and speed-square hacks printed right on the square. It has very fine measurement markings and feels like a really well-made piece of kit for the price. I have used speed squares for twice the price that weren’t as well machined and it’s light enough to carry on your tool belt. Great buy.
You can pick one up from the Home Depot at the Below link.
Check back for Part 2 Next Week. Until then…
Keep your tools sharp and your mind sharper.
Rick
I acknowledge that The Home Depot is partnering with me to participate in the promotional program described above (the “Program”). As a part of the Program, I am receiving compensation in the form of products and services, for the purpose of promoting The Home Depot. All expressed opinions and experiences are my own words. My post complies with the Word Of Mouth Marketing Association (WOMMA) Ethics Code and applicable Federal Trade Commission guidelines.
