This was a fairly big project in terms of research, planning, finding materials, getting the materials shipped and finally putting it all together. I finished it a year ago. I am very satisfied with how it turned out. I think everybody should build their own mattress for a few reasons: you know what’s inside, you can replace any individual component for a fraction of the price of a new mattress, if something doesn’t work you can modify the internals of the mattress rather than buying a “topper” to try to cover up a problem, and in the long run it will cost less because you never replace the entire thing.
Materials and content of mattresses
We all know the basics of mattresses: springs, foam & a large fabric encasement with some fluff to hold it all together. That’s not all though, there are usually glues to hold pieces together, and fire retardants either chemical or physical. Do a search for “toxic mattress” to discover all the different possible chemicals that could be in your mattress. It’s complicated, and difficult to know which specific chemicals are in your mattress since manufacturers don’t want to disclose them unless legally required to – it’s more common as a marketing ploy for mattress sellers to list which ones are not in the mattress, while just not listing the ones that are.
- Memory foam: that’s crude oil refined and turned into a foam product (that means chemical processes). It’s not recyclable, only reusable, and it is up to government to enforce the reuse option since it is so cheap to produce and most governments do not have requirements for mattress recycling. It’s known to off-gas for quite a long period and may be irritating to some until it stops. Cheap mattresses use lower quality foams that break down more rapidly so you replace everything much faster than a more expensive one. It generates a lot of waste.
- Polyurethane bases: more crude oil. The end result is a firmer product designed to add height rather than provide comfort. Springs are far more durable, longer lasting, will be recycled, and much better for the environment.
- Latex foam: latex is made from the sap of a rubber tree. It is more expensive than memory foam, but is also more durable and cooler to sleep on than memory foam. Since it will last longer than memory foam, it is cheaper in the long run. There are two main processes to make it dunlop and talalay with different properties. This foam can be produced fairly ecologically or with some chemicals to improve the foam generation.
- Glues: commonly used to weld multiple pieces of foam together to prevent slippage during manufacturing. Whether you know what glues if any are used would be up to government requirements, and listed on the label. They can be large contributors to off gassing and many glues use formaldehyde as one example that you’ve probably heard of.
- Fire retardants: these can be broken down into definitely carcinogenic chemicals, probably not carcinogenic chemicals, and natural (wool or glass thread). Early flame retardants were mandated by law to be included in furniture so they were everywhere but later found out to cause cancer. Newer chemicals were found and some laws updated (California is at the forefront of this, so look for California specific labels in regards to figuring this out). Matted wool is an all natural flame retardant. The glass thread is FDA approved, but does break down over time, the mattress should not be opened without PPE, and can damage your lungs if any broken fibers are inhaled and the broken fibers are a skin & eye irritant.
Mattresses don’t last as long as they used to
Before memory foam really dominated the market it was fairly common for mattresses to be flippable. Every few months you would rotate the mattress 180 degrees, then a few months later you would flip it onto its other side, sleep like that for a few months, then rotate, then flip, ensuring even wear. This requires a supportive core with equal padding and finishes on both sides. Nowadays a mattress like that is hard to come by and very expensive compared to the other options.
Most mattresses produced today use either springs or a very stiff foam base as the bottom layer to the mattress and then add one or more layers of foam on top, so if you were to flip it, you wouldn’t be comfortable at all. So now our mattresses wear twice as fast because we can only rotate them. The majority of mattresses sold now are also made of materials that are cheaper and less durable, so we can spend less per purchase but do so more frequently.
Worst yet, the first part of the mattress to fail is going to be the upper layer(s) of the mattress. If you use a mattress cover, a 5 year old mattress fabric encasement will likely look brand new. The base of the mattress, whether springs or a foam base, will have little to no wear and could be used for much, much longer with no problem. If you could just replace the top layer(s) you’d be set for a much lower cost than buying an entirely new mattress.
Can’t I just get a mattress topper and remake the comfort profile of an old mattress?
It depends on the issue you’re facing. If there are hills and valleys, it won’t do much to level things out, your hills and valleys will just be raised up and still noticeable through the topper. If the bed is too firm for your liking but otherwise sound, yes it will make a difference. If your bed has less noticeable issues, try getting a latex foam slab instead of memory foam. It’s pricier, but it is also stronger and will transfer less of the underlying deformities than memory foam would.
What if you could open your regular mattress up and just flip the individual layers?
That would definitely help increase the lifespan of the mattress and your overall comfort if you could, but it’s not really practical. If the mattress uses glass threads for fire retardant, then it’s dangerous to even open the fabric casing, and that entire mattress is sealed inside the glass thread – you would have to cut it off. Then all the foam layers are heavily glued together. Trying to separate them would be difficult and likely result in masses of foam tearing apart unevenly. There’s also the glue dust – you don’t want that near any eyes or orifices. Don’t try this. If you do try this, wear PPE.
If you build your own DIY mattress you can flip every layer independently and replace layers at will.
Because you put all the components of the bed together in place you don’t have to worry about layers shifting like they would during the manufacturing process, so no worries about glues. You know everything inside the bed is safe to open, take apart, flip and reassemble. Super easy. A diy mattress will wear more evenly and last longer because of this. If your top layer is wearing out and you want to replace it, you only pay for that single layer, and the waste you are generating is limited to that layer. If you are an individual who requires fire retardants for your mattress, make sure you get a cover that either has 1″ of wool on top or add something that has fire retardant properties in the cover itself.
How I planned and built my diy mattress
I knew I wanted a durable pocket coil base, around 6″ tall, and a latex slab on top of that. Whether I wanted the firmness to be medium or soft for the latex slab was another question, which meant I was going to order the medium slab first, and if it was too firm, I would order a soft layer and just have a taller bed.
There are not a ton of choices for pure coil spring bases, so the Leggett and Platt Caliber Edge 6″ King size was my choice. Kind of pricey and no free shipping, but it should last a very long time under the latex slabs. I was concerned about foam sitting directly on top of this, but the marketing images are not what it looks like in real life. IRL there is non-woven fabric connecting all the springs that the foam will sit on top of.
For the latex I knew I wanted to purchase from a company that made an effort to make a greener product and found Sleep on Latex where I bought a 3″ Medium firm King size slab. They carry the following certifications: Greenguard Gold Certificate, Oeko-Tex Certificate, ecoInstitut Certificate, GOLS Certificate. I was quite happy with the medium firmness, but my opinion isn’t the one that counts the most, so I went ahead and ordered a Sleep on Latex 2″ Soft King size slab to go on top of it, and everyone was happy.
While I was testing the firmness and while I was waiting for the mattress encasement, I just put this King Size Mattress Protector over the layers, and then made the bed normally on top of that.
Once I had my inner mattress height of 11″ I could find a mattress cover to hold everything together and offer protection to the layers inside. This is a surprisingly difficult thing to search for, because the terminology is intermixed between covers that stretch over mattresses and are just protectors, zippered covers that cover all sides of the bed, but are thin and meant to offer only protection, and the infinitesimally smaller category of real honest to god mattress covers to cover mattress innards. I found SleepEz.com and their Natural Cotton and Wool cover to be ideal. The 12″ cover contains the 11″ of inner layers plus has 1″ of its own height for the wool layer for a total of 12″.
Issues to look out for
When you consider a King size mattress is officially 76″x80″ (in the USA, other regions vary). Naturally the thickness of the walls of the cover should account for some of that, so you would expect the inner components to measure just under that. The reality was very different, and I can only account for the products that I purchased, other vendors may conform to sizing better. For the Caliber Edge base, the width is perfect at 75.5″ but the length is 78.25″ which is about 1.25″ short. The two latex layers were off a bit more, but according to the seller, within their margin of error. As a natural product with some give it’s kind of understandable. The 3″ layer measured 75″ x 77.25″ and the 2″ layer 76.75″ x 78.5″. Sleep on Latex will give you a replacement if there are any sizing issues outside of their margin of error.
When I assembled everything inside the mattress cover, things were fairly tight around the coil springs. The medium foam layer had little gaps on the sides, and the top and bottom were 0.5″ shorter than the coils. The top layer overhung the sides of the middle layer by 7/8″ and had to be compressed a little to fit in the mattress cover. Zipping it up was a little tight, which is good because it means it is holding everything together quite well.
Reasonably cheaper alternatives
Buy a very cheap and short mattress and add a layer on top
This is something I considered heavily, and there are some 6″ tall coil mattresses or 8″ coil + foam (medium to firm) that would be perfect, but I wanted to avoid unknown fire retardants and other possible chemicals, and off gassing memory foam. If that’s not part of your selection criteria then these would be good options. A 3″ foam slab would be fine.
Flip your old mattress so it is base side up and add a layer on top
If the sleeping side of your mattress is worn out, and the mattress height could be 3-5″ taller then this would be the least expensive option of all. Your only expense would be the foam slab and a cover. Make sure you check the bottom side for any irregularities first. Since the base is firmer you may need a foam slab thicker than 3″ for comfort.
Use a box spring as the base
Take a basic box spring mattress, and add 2 layers of foam on top, one firmer above the box spring and a softer layer on top for a total of 5-6″. If the first layer of foam is not rigid enough to span the supports in the box spring of your choice, you will need to add a firm layer to support the foam.
Covering the layers for any solution above
You can cover both the base of choice and foam slab with a basic mattress protector, or if you want to cover all 6 sides you can get a zippered mattress protector, or better yet, to look like a finished bed, you could get a custom mattress encasement made that is slightly longer and wider to accommodate a finished mattress inside of it. Sleeping directly on foam without a breathable layer in-between may be uncomfortable – especially memory foam since it retains heat very well. Wool blankets are a good option to place directly on top of the foam and underneath the cover for breathability. Many custom mattress encasements will be able to add wool for you.
There are sites that will let you customize, based on their available options the components of the bed and cover and ship it to you pre-made. I did not use any of them, so I cannot recommend anything.