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How would you build this bunk bed?

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Forum topic by Derrick posted 01-23-2018 10:16 AM 744 views 0 times favorited 15 replies Add to Favorites Watch
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Derrick

84 posts in 1314 days


01-23-2018 10:16 AM

My two boys have expressed an interest in bunk beds. Right now, they both sleep in separate queen beds(which is total overkill for their age). If we decide to go with bunk beds, we would be utilizing their current mattresses. Neither needs a box spring, so that could cut down on the overall height. Looking around the web, I’ve found a few queen over queen beds that would work. This is the one I keep coming back to though:

It’s a full over queen, but it’s close enough. It looks like it could be made out of dimensional lumber, but I’m concerned about the joinery. I guess concerned isn’t the right word. Curious is more like it.

The corners are my first question. What would be the sturdiest method for joining the corners at a 90* angle to each other? There’s an article out there(that I’ve since lost the link for) where a person made a loft bed with similar corners, and all he did was glue/screw. Pretty basic stuff. Is it the most effective though?

The rails are also where I have questions. It’s hard to tell, because I only have this one picture, but I’m guessing that all of these joints aren’t just butted up to the corners. I’ve seen other designs that have bolted half-lap joints. Would that be a safe method? Even though this design looks to be fairly simple, it’s still a lot of weight being held up. That’s what I’m most concerned about.

So my question is, if this was the design that you decided on, what joinery would you use, and why?

Any help would be awesome.

Thank you.

Derrick


15 replies so far

View jmos's profile

jmos

894 posts in 2546 days


#1 posted 01-23-2018 12:59 PM

You’ve got a lot of options.

For the corners, you’ve got a lot of face grain to face grain area, and a glue joint would probably be strong enough. However, it’s easy to reinforce the joint with dowels, a spline, or floating tenons.

To attach the rails, keep in mind a lot of the joint is hidden, so you don’t have to be too fancy. You could butt the rail between the corner posts and screw and glue a separate board across the rail and corner to join them. You could do a sort of half-lap joint, where you notch the rail, and notch the corner, so that the rail fits into the notch in the corner, then screw and glue it in place. I’d probably go this route, very strong, good mechanical support, lots of glue surface. Floating tenons would also work well. As you said, you could go with through carriage bolts, would would be really strong, but you’d either have to like the look, or recess and cover the bolt heads, which would be large, noticeable covers.

For a queen I would also install a hidden rail running head to foot in the middle for more support on the top bed. This could be mortised and tenoned (or loose tenoned into the end rails.) Then use a bunch of 1×4 slats to support the mattress. For the lower bed I’d use a center leg or two on full width slats to prevent sagging.

-- John

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jmos

894 posts in 2546 days


#2 posted 01-23-2018 01:10 PM

For the rails I forgot to mention the traditional method – use a short tenon on the rail into a mortise on the leg and use bed bolt hardware to lock them in. This is usually used to join the side rails. The headboard and foot board are typically permanently attached.

Another question you’ll have to address is whether you want to be able to take this apart to move it, or if you want it permanently assembled. If the later, you’ll need a saw to get it out of the room. If the former, I’d probably skip gluing any of the rails and use screws or bed bolts.

-- John

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bilyo

394 posts in 1279 days


#3 posted 01-23-2018 04:00 PM

First, a couple of observations: I know that looking at a picture, my perspective could be off a bit. To my eye, the whole unit looks a bit tall and I can’t help but wonder if the upper bunk will have good head room under a ceiling. Also, could the lower bunk be raised just a bit? Remember, someone will need clean the dust bunnies and toys out from under it.

To your questions: I would be inclined to make the corner posts by mitering the corner with a spline. This would be one of the more difficult methods, but by doing it this way, it will not only be strong, but the joint line will be masked by the corner and the grain will seem to wrap around the corner. I would use epoxy for this as it will give you lots of working time to get it assembled and clamped. Be sure to keep the corner square during glue up.

I agree with jmos. One of your primary concerns is designing in the ability to break it down for moving. Since you are working with queen size, I think it will be difficult to make single headboard/footboard components because of the ultimate size for moving. You will need to do some measuring to see if you can glue all those pieces together and still be able to move them where you need them. Otherwise, most everything needs to be assembled with removable fasteners.

I have built a couple of beds with exposed fasteners where the rail fastened to the footboard/headboard. I used a simple overlap (no dado) with exposed hex head bolts, The heads were countersunk and inserted from the outside into “T” nuts on the inside. I sanded off the cadmium plating and then used gun bluing to darken them. Looked good to my eye. You could also do the reverse and insert screws from the inside out into threaded inserts in the backside of the post. Be sure to use enough and make the bolt holes snug to resist racking of the whole system. Extending the side rail all the way into the backside corner of the post will also provide some rigidity.

I would support the mattress with a sheet of plywood supported by ledgers around the perimeter and two or three cross pieces. Remember that a queen size mattress will be larger than a single sheet of plywood. So, the mattress support will require two pieces. You will need support at the seam; probably crosswise at the midpoint.

View Derrick's profile

Derrick

84 posts in 1314 days


#4 posted 01-23-2018 05:49 PM



You ve got a lot of options.

For the corners, you ve got a lot of face grain to face grain area, and a glue joint would probably be strong enough. However, it s easy to reinforce the joint with dowels, a spline, or floating tenons.

To attach the rails, keep in mind a lot of the joint is hidden, so you don t have to be too fancy. You could butt the rail between the corner posts and screw and glue a separate board across the rail and corner to join them. You could do a sort of half-lap joint, where you notch the rail, and notch the corner, so that the rail fits into the notch in the corner, then screw and glue it in place. I d probably go this route, very strong, good mechanical support, lots of glue surface. Floating tenons would also work well. As you said, you could go with through carriage bolts, would would be really strong, but you d either have to like the look, or recess and cover the bolt heads, which would be large, noticeable covers.

For a queen I would also install a hidden rail running head to foot in the middle for more support on the top bed. This could be mortised and tenoned (or loose tenoned into the end rails.) Then use a bunch of 1×4 slats to support the mattress. For the lower bed I d use a center leg or two on full width slats to prevent sagging.

- jmos


For the rails I forgot to mention the traditional method – use a short tenon on the rail into a mortise on the leg and use bed bolt hardware to lock them in. This is usually used to join the side rails. The headboard and foot board are typically permanently attached.

Another question you ll have to address is whether you want to be able to take this apart to move it, or if you want it permanently assembled. If the later, you ll need a saw to get it out of the room. If the former, I d probably skip gluing any of the rails and use screws or bed bolts.

- jmos


First, a couple of observations: I know that looking at a picture, my perspective could be off a bit. To my eye, the whole unit looks a bit tall and I can t help but wonder if the upper bunk will have good head room under a ceiling. Also, could the lower bunk be raised just a bit? Remember, someone will need clean the dust bunnies and toys out from under it.

To your questions: I would be inclined to make the corner posts by mitering the corner with a spline. This would be one of the more difficult methods, but by doing it this way, it will not only be strong, but the joint line will be masked by the corner and the grain will seem to wrap around the corner. I would use epoxy for this as it will give you lots of working time to get it assembled and clamped. Be sure to keep the corner square during glue up.

I agree with jmos. One of your primary concerns is designing in the ability to break it down for moving. Since you are working with queen size, I think it will be difficult to make single headboard/footboard components because of the ultimate size for moving. You will need to do some measuring to see if you can glue all those pieces together and still be able to move them where you need them. Otherwise, most everything needs to be assembled with removable fasteners.

I have built a couple of beds with exposed fasteners where the rail fastened to the footboard/headboard. I used a simple overlap (no dado) with exposed hex head bolts, The heads were countersunk and inserted from the outside into “T” nuts on the inside. I sanded off the cadmium plating and then used gun bluing to darken them. Looked good to my eye. You could also do the reverse and insert screws from the inside out into threaded inserts in the backside of the post. Be sure to use enough and make the bolt holes snug to resist racking of the whole system. Extending the side rail all the way into the backside corner of the post will also provide some rigidity.

I would support the mattress with a sheet of plywood supported by ledgers around the perimeter and two or three cross pieces. Remember that a queen size mattress will be larger than a single sheet of plywood. So, the mattress support will require two pieces. You will need support at the seam; probably crosswise at the midpoint.

- bilyo

Wow! Thank you guys for being so descriptive!!! Bilyo, I think you’re right. I think the bed does look very tall. Everything would have to be adjusted to work with my 8’ ceilings. The bottom could definitely be raised up a bit, and the top would need to come down. I think they should both be able to sit up in bed without hiting their head on the ceiling or the underside of the top bunk.

The thought of whether or not I want to be able to take it down or not did cross my mind. They’re not going to have bunk beds forever. Since I’d be doing this with dimensional lumber, I don’t think I’d have too much of an issue cutting it up to remove it. I’ll let my wife decide on that on though.

You two have given me plenty to work with.

Thank you very much!!

View jbay's profile (online now)

jbay

2764 posts in 1075 days


#5 posted 01-23-2018 05:56 PM

How funny,
I’m getting ready to build something similar.
Mine will have a pop up trundle bed under the bottom bunk.

-- “Hanging onto resentment, is letting someone you despise live rent-free in your head.” (Ann Landers)......

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Mario

182 posts in 3572 days


#6 posted 01-23-2018 06:08 PM

You could certainly build it several ways but if it was to be built as the one in the image, a Festool Domino and glue combination would make a quick job out of it and sturdy enough to survive a couple youngsters.

View bilyo's profile

bilyo

394 posts in 1279 days


#7 posted 01-23-2018 07:17 PM


The thought of whether or not I want to be able to take it down or not did cross my mind. They re not going to have bunk beds forever. Since I d be doing this with dimensional lumber, I don t think I d have too much of an issue cutting it up to remove it. I ll let my wife decide on that on though.
- Derrick

Understood. However, don’t forget you have to get it from the shop to the BR somehow unless you do the assembly there. Will you pre-finish the pieces or do both assembly and finish in the BR?

View Walker's profile

Walker

146 posts in 648 days


#8 posted 01-23-2018 08:01 PM

if you do need/want to make some of the joints reversible for ease of transport….rockler has some beefy cross dowel bolts. They worked great joining the 4×4’s I used to build my workbench. Striplox is a company with some new(ish) products that work like bed rail connectors but more sleek.

-- ~Walker

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Mario

182 posts in 3572 days


#9 posted 01-23-2018 08:05 PM

I would pre-finish the largest sub-assemblies that would fit through the door and do the final assembly/touch up inside.

View Markespen's profile

Markespen

8 posts in 650 days


#10 posted 01-24-2018 02:06 AM

I’ll throw in my two cents. Someone suggested using plywood under the mattresses. If plywood is used, it needs to have large holes drilled throughout each sheet to allow the mattresses to breathe. A grid of holes cut with a hole saw bit would work. Otherwise moisture would get trapped and potentially cause mold to grow. Moisture build up is the reason box springs are used and bed frames utilize slats instead of solid sheeting.

-- Mark - Owasso, OK

View Derrick's profile

Derrick

84 posts in 1314 days


#11 posted 01-24-2018 02:16 AM



How funny,
I m getting ready to build something similar.
Mine will have a pop up trundle bed under the bottom bunk.

- jbay

That is a pretty cool looking setup! What is the overall height? I like the trundle bed feature, but don’t know if I could comfortably squeeze everything in with 8’ ceilings. They like to have sleepovers, and that would make things real convenient.

Thank you for sharing!


You could certainly build it several ways but if it was to be built as the one in the image, a Festool Domino and glue combination would make a quick job out of it and sturdy enough to survive a couple youngsters.

- Mario

I don’t have a festool in my lineup of tools, but I see what you’re getting at. I’m a pretty good salesman, but I don’t think I could sell this to my wife as a reason to buy a new tool.


if you do need/want to make some of the joints reversible for ease of transport….rockler has some beefy cross dowel bolts. They worked great joining the 4×4 s I used to build my workbench. Striplox is a company with some new(ish) products that work like bed rail connectors but more sleek.

- Walker

I’ll have to take a look at those.


I would pre-finish the largest sub-assemblies that would fit through the door and do the final assembly/touch up inside.

- Mario

That’s likely what I’d have to do. I’m not a fan of finishing in place, but this thing is massive, so some of it will have to be.


Understood. However, don t forget you have to get it from the shop to the BR somehow unless you do the assembly there. Will you pre-finish the pieces or do both assembly and finish in the BR?

- bilyo

Yeah, I think like Mario said, I would probably break it down into sub assemblies. The largest I could safely get through the doors. Then assemble/finish in place. It’s not ideal, but because of the room I have, it’s probably my only option.

Thanks again everyone!!!

View jbay's profile (online now)

jbay

2764 posts in 1075 days


#12 posted 01-24-2018 02:47 AM


How funny,
I m getting ready to build something similar.
Mine will have a pop up trundle bed under the bottom bunk.

- jbay

That is a pretty cool looking setup! What is the overall height? I like the trundle bed feature, but don t know if I could comfortably squeeze everything in with 8 ceilings. They like to have sleepovers, and that would make things real convenient.

Thank you for sharing!

- Derrick

Mine is 79” to the top. It’s going in a room with a 10’ ceiling.
Check below to see some standard sizing.
https://www.bing.com/images/search?q=bunk+bed+standard+sizes&FORM=HDRSC2

-- “Hanging onto resentment, is letting someone you despise live rent-free in your head.” (Ann Landers)......

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avsmusic1

273 posts in 861 days


#13 posted 01-24-2018 02:54 AM

I’ve never heard of the moisture thing and am a bit skeptical having owned platform beds with plywood support w/ a mattress only. I never had any issues but I suppose that doesn’t mean nobody would, and I guess the 10min it would take to add the vents to the ply may be worth it just in case

View Derrick's profile

Derrick

84 posts in 1314 days


#14 posted 01-24-2018 06:17 AM


Mine is 79” to the top. It s going in a room with a 10 ceiling.
Check below to see some standard sizing.
https://www.bing.com/images/search?q=bunk+bed+standard+sizes&FORM=HDRSC2

- jbay

Man. Maybe I should’ve been using Bing. Looks like I can get away with 73-75 inches of overall height, and still keep the bottom bunk at a decent distance from the floor, and give either kid that decides they want the top bunk, plenty of room without hitting their head on the ceiling.



I’ve never heard of the moisture thing and am a bit skeptical having owned platform beds with plywood support w/ a mattress only. I never had any issues but I suppose that doesn’t mean nobody would, and I guess the 10min it would take to add the vents to the ply may be worth it just in case

- avsmusic1

I’ve heard of it, but never experienced it. I was researching another type of bed, and it utilized holes punched in the plywood specifically for that purpose. Just to be on the safe side, adding some vents would not be a problem. My initial thought was to use slats with a center support as well.

I’ve seen different examples(I know there are plenty of ways to skin this cat). I was thinking 2×4’s flipped on their side in an “I” set up, and then have a few of them spaced out. I’ve seen 5-6 spaced evenly for a bed of this length/width. Since I’d be using a center support, I’d imagine that I’d have to do a half-lap where each of the slats crossed it.

I can visualize the support system in my head. Putting it to words is the tough part.

View bilyo's profile

bilyo

394 posts in 1279 days


#15 posted 01-24-2018 07:41 PM


I’ve never heard of the moisture thing and am a bit skeptical having owned platform beds with plywood support w/ a mattress only. I never had any issues but I suppose that doesn’t mean nobody would, and I guess the 10min it would take to add the vents to the ply may be worth it just in case

- avsmusic1


Markespen is correct. I learned this the hard way many years ago. After the mattress was ruined, I bored holes in the plywood and never had the problem again. If my memory is correct, I drilled (hole saw) about 1” holes in a grid about 4-5” OC.

The mattress I had the problem with was foam. I’m fairly certain, if you use foam, you will have a problem without vent holes. I’m only guessing, but an innerspring mattress be less likely to have problems due to better interior air circulation. Again, just guessing. To be safe, the effort to vent is minimal.

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