I am soooo excited! I have been waiting to write this post ever since I read Miss Mustard Seed’s post about her new guest bed! Here’s what she says:
One reason we had just a metal frame for our own queen bed for so long is that I couldn’t find an antique bed frame that would fit a queen mattress and I couldn’t find a new bed that had the antique look I was going for. (I know you can sometimes convert a full to a queen, but I haven’t heard many success stories with that.)
Well my friends you are about to hear a success story! My mom bought this double size antique cast iron bed frame for me straight out of college. So that means I have been sleeping on my antique double bed for almost 5 years. We took it home and set it up in our guest room… I hadn’t moved out yet and we wanted to see how it looked. We knew right away that if we wanted it to work we would have to find a way to convert the rails to a queen size… a double just wouldn’t cut it.
So we did some research. A Queen size bed is both longer and wider than a double… so in order for the conversion to work the rails have to become longer to support the added length… and you have to be okay with a little overhang. The Queen size mattress will be a tad bit wider than your headboard and footboard. Luckily I really haven’t had a problem with it!
So what exactly are the steps? Well friend, I’m glad you asked!
UPDATE: Want to see this little bed after 10 years of use? I update it here!
Step One!
Longer rails! In order for the larger mattress to fit your bed rails have to be about 6 inches longer. See where the seam is on the rail above? That’s where the extention was welded on. If you are an expert antique cast iron welder then don’t bother asking me for tips… go lengthen those rails! If you happen to be in the 99.9% of the population that doesn’t know how to lengthen cast iron (that would be me!) it’s ok! We did a quick google search for extended queen bed rails and were able to find a gentlemen who specializes in this sort of thing. That was five years ago so I don’t remember exactly where he was… but he shipped the rails to us in Colorado so you don’t have to be local! Score!
Of course if your little brother is helping you put your bed together and doesn’t realize you can’t use a hammer to put cast iron rails into cast iron pin holes… you may need a second set of rails! Did you catch that?! If you use a normal hammer to put your rails together THEY WILL BREAK!! Take it from me and use a rubber mallet! It’s not worth it!
Luckily fate was on my side and I happened across a pair of already extended rails at an antique store for a very good price. Someone must love me.
See the point where the rails fit into the joint? Do not hit those with a hammer! USE A RUBBER MALLET! I don’t want what happened to me to happen to you! Learn by my mistakes grasshopper.
Step Two!
We made the bed longer… now we have to make it wider. Mainly because our larger mattress will not fit down into the rails like a double size mattress would. This part is easy… all we need is a couple two by fours! Cut three pieces as wide as your mattress… then cut 12 smaller pieces… nail them together like so.
Now your mattress has a great platform to sit on top of!
Side note: Make sure your boards are only as long as your mattress… I thought it would be a good idea to make mine a bit longer so the bed had room to slide. Not a good idea. I have permanent bruises on my legs from hitting those darn boards in the middle of the night. They are not 3am potty run friendly.
And that’s it! Now you have an antique QUEEN bedframe! Slap your queen mattress on top and take a nap. Heavenly isn’t it?
So tell me… could you tell my bed was converted?
P.S. Did you catch the sneak peek into our new bedroom at the new house?!
P.P.S. DIY Lamp Transformation… How to Color Transparent Glass and How to Accessorize your Nightstand

















I’m in awe since I’m not craft at all. You did an amazing job!
Thank you Joyce! It was kind of a crazy project! We had already bought the bed so we had to make it work!
I think this is a great idea for a bed frame someone may have had that a queen didn’t fit into a room, but then move to a larger place. The frame could be easily upsized and recycled without having to buy a larger one. A penny saved is a penny earned!
It’s always nice to make what you have work instead of buy a new one! Thanks for stopping by Sue!
this is something I will definitely be pinning! I love vintage/antique beds so I know this will come in handy.
Thanks for stopping by Jessica! I love my antique bed, hope you find a beautiful one!
Resent gifted two and considering the stretch to queen on one, Thanks for the info
It’s semi-unrelated to this, but next year at college I’ll have a full size bed but I only have a twin size comforter. I decided the twin would look strange with no fabric hanging off the side, so I searched for a new comforter. The one I love only comes in a queen–luckily too big is better than too small! Nice work with your conversion.
Thanks for stopping by Sabina! Kudos on having a full size bed in college! I was stuck in a twin all four years, haha! I totally agree, too much overhang is way better than not enough… in fact I like to buy my comforters big on purpose that way there’s plenty of overhang… otherwise my hubby and I fight over the covers all night!
Beautiful bed frame, and such an informative post!
Thanks Jessica! I’m glad you like it!
Cute idea, thank you!
Wow, so clever. I love being able to restore and reuse things especially those items you love and have an attachment to. The bed looks great!
You’re so sweet! I think restoring is the best… the craftsmanship in the past was so much better! Thanks for stopping by!
What a fantastic idea! My husband and I have been saying we need a much larger bed – this looks totally do-able. Visiting from the Pretty Pintastic Party!
Thanks for stopping by Kelly! It’s definitely a great way to get a larger bed with the same frame!
This is a great idea. It allows one to keep a “too small” bed and make it work.
I agree! And I really think it looks just fine!
Great idea. This is the way beds are made in Europe. Just a ton of wood pieces on the bottom. And if one breaks j ust replace it. Very clever idea!
I never thought of that… but you’re so right! Europeans have all the good ideas!
GENIUS!!! is all I have to say lol great job!
Thanks Ak! I love how it turned out… and after almost 5 years it’s still holding strong!
I really wish I had the skills to DIY this. I want the antique look for my bed frame, but I’ll have to buy one and just save our frame for my daughter to use someday. Cool post, though – that frame looks great!
It’s really more ordering than DIYing but I completely understand… as much as I love this bed it will probably move to a guest room or daughters room down the road when we upgrade to a king sized bed. In the meantime Queen is so much better than a Double!
Excellent job Betsy! I think you did great! I love the idea but I’m kinda hesitant if I wanna try this, i am afraid I’ll just mess up. lol. Anyways, thank you for sharing! 🙂
Thanks hon, you’re so sweet! It’s super easy… Not much to mess up! If you cut your two by fours wrong just get a new board!
Memory foam is something that we have wanted to invest in for some time now, and we might be able to do so this Christmas. Some of the prices we have seen are ridiculous, but around 549, like what you have listed here for a queen, seem like a good deal. Thanks for listing more information about foam mattresses, as well as their prices.
It was a great deal… we just bought another one for my brother when he needed a new mattress. We loved that mattress for over 10 years and it was so comfy. We did get rid of it when we moved houses and upgraded to a Sleep Number Bed though which I am OBSESSED with. Good luck with your new mattress!
“How to Turn Your Antique Double Bed into a Queen” is awesome. The antique bed is transformed into a new bed, even the mattress fitted well.
Thanks! I think it was a pretty easy solution to making the bed into a queen. The mattress looks fairly decent as well.
I loove the antique bedframe. What a great project and the story!
Isn’t it a great bed?! You’re such a sweetheart! Thanks for stopping by!
This is such a cool and unique idea. It is amazing that you were able to turn this double bed into a queen sized bed! How did you go about figuring out how to do this? This is definitely something that I would want to try out in my own home one day!
My mom actually taught me how to do it… I have no idea how she learned it! Crazy the kinds of things parents teach us! 😉 Thanks for stopping by Elise! Good luck if you try this in the future!
nice idea to share with us. thanks admin
I have a very similar frame, full size and very short. It’s been in the family over 50 years and I hate to part with it. Thanks for the ideas! My guests will appreciate sleeping in a larger bed for sure! BTW- how much did the welder charge you for lengthening the sides pieces?
Nan,
Thanks so much for stopping by! It sounds like you have the perfect bed for this little trick… what a wonderful bit of family history! It was over 5 years ago that I had these rails lengthened so I don’t remember exactly but I feel like it was in the ballpark of $100. Good Luck!
I called a metal fabricator here n town. They extended my rails for $40. Your wood setup is not supporting much and it putting strain on the rails. Cut the boards to fit into the grooves and add legs underneath. Then buy L brackets to extend out 3″ on each side. screw them on and viola your box bring is going nowhere
Thanks for the opinion Vikki! My wood setup has been working wonderfully for almost 10 years now without any strain on the rails so I love it. I can see how additional legs would add support but no more than an extra leg would provide support to a double sized bed using the rails as intended. I love that you took the time to read the entire post though, I appreciate your comments! Have a great night hon!
Awesome j0b!!! Thank you so much for the detailed instructions. I just bought an Antique Mahogany 4 Poster bed and wanted to put my Queen mattress on it. Yeah, now I can. Thank you. Great job!
Thanks for your post, very clever and not too hard for a non-handy person! Did you install a box spring and mattress, or leave the box spring off altogether?
We used a low profile box spring so it’s pretty trim! Thanks for stopping by Debbie!
Great job. I would like to see a pcture that includes both sides of the bed. This would give me a better idea of how much wider the mattress appears on the frame. I’m considering converting a waterfall wood bed and am concerned about the finished esthetic.
Hi Lisa, Thanks so much for your comment. I actually did a post last year where you can see both sides of the bed with the mattress and linen on the bed. Let me know what you think! Good luck with your bed!
Hi, This is great BUT I have wood rails and would love to make the full fit a queen. Any ideas?
If you have wood rails the same concept should work you will just want to build the new rails on top of the wooden rails you already have. Good luck!
Great, Here you have mentioned the easiest way to turn your antique double bed into a queen that really help people like me who can not afford a new queen size bed. Keep sharing this kind of informative idea with us.
This os such an interesting idea! Does the mattress slide along without any edges on the wood?
Not anymore than a traditional bed! I had no problems with it sliding for years when using it by myself… once we added the hubby it did slide a little over the course of a month since he plops on everything… but not on a daily basis.