Engineer staterments, link to joinery and gap studies, links to tests (Ikea)
There are many variables to consider when analyzing the options that are available and I scratched my head about how to write this article.
Best wood bed slats are on the Super Strong Bed. Slats with least sag: birch, popular, fir, maple, oak, and ash with 3.5″ width, 0.75″ thickness, and 2.5″ gaps. Best metal bed slats are aluminum, steel, and alloy at least 1″ wide grid. The best is the SmartBase Super Heavy Duty Mattress Foundation.
Best Wood Bed Slats
The bed with the best wood bed slats is the Super Strong Bed,
This is tough as the best might not be good. The best are the ones that you build yourself to match the foundation for which they are to be installed. This way you can design and overbuild them to make sure they will not sag, break, or fall through the frame after a few months.
I rated models out of 10 based on the following criteria:
- Wood species/type
- Squeak and noise potential
What to Look For When Researching
- Look for beds with slats that are screwed to the frames to reduce noise potential and increased strength.
- Wood species and the strength and flex (you can check wood mechanical properties here and strength properties here)
I only did this for models that I thought had a chance to make this list so that I didn’t waste too much time with this project.
For example, I did not look at any Ikea options as my research over the past year leads me to believe they should be avoided when possible.
I also did not factor in cost since this is a list of the best overall regardless of the prices.
Some companies have designs that are well engineered and this is very important since we spend so much of our lives on this piece of furniture. Think about how many hours per day you spend sitting on a chair while eating dinner. How many hours per day are spent on this piece of furniture.
And if you are like me I focus on the strength and sturdiness of chairs when shopping for a table and chair set. I think the bed deserves at minimum the same considerations when shopping.
Unfortunately, the design that increases the strength of the bed while substantially reducing sagging and noise is not used in most models. This is baffling to me.
As you can see in the table below, simply fastenting the slats to the frame on each end reduces sag by about 75%!!!
I realize that manufacturing costs would go up slightly due to having to drill holes in the slats and providing fasteners, but this would be a tiny cost for a gigantic increase in strength.
And yes, many customers would wine about having “extra” work to assemble the unit. But come on, let’s not be this lazy. An extra 30 minutes of assembly time to decrease sag by 75% is a smoking deal!
Is the company using pine 1×3 or 1×4″ that you find in the lumberyard of most hardware stores in USA and Canada. Below is a list that compares the strength of various wood species and a few important notes include:
- Assuming 30 lbs per foot, which is likely high.
- Center loading (because people are not a flat block and people usually sleep on the middle of a slat).
- Fixed means the ends of the slats are fastened to the frame. Not fixed means floating on top of frame rails.
- I used the Sagulator calculator at the Wood Bin website.
- Results are based on Queen size bed frames with 27″ of total clear span by each slat (assuming a center support beam/rail/frame).
- Wood slats that are 3.5″ wide and 0.75″ thick, which is the true width of 1″x4″ lumber.
Wood bed slats are typically 0.75″ thick and made with a solid piece of wood or plywood. The sag of the slats of the same wood species decrease approximately:
- 50% for 1″ thick (fixed and floating)
- 88% for 1.5″ thick (fixed and floating)
Wood slats are usually between 2.5 inches and 3.5 inches wide. These are two common demensions of lumber, which is a convientent supply of material for the production of furniture.
It would be beneficial if wider options were available to provide a stronger frame and more support for mattresses, but the cost of the additional material is a luxury most buyers are not willing to pay for.
The additional weight also presents shipping challenges as many wood bed frames are already near the weight limit for most shiping companies for reasonable shipping costs.
Wood bed frames typically have slat gaps between 2.5 inches and 4 inches. This is much less than most metal options and therefore is a better foundation for a mattress.
Many mattress companies have warranties that require the gaps not to exceed 3 inches so this is an important design characteristic to consider before making a purchase.
Squeak and noise potential
Wood bed slats squeak and creak less than metals ones that are installed on a metal bed frame. Rub two pieces of metal together and then two pieces of wood. Which is louder and more annoying? Right, metal. Wood is also much easier to modify if your foundation starts creating noises later since you can easily remove components, modify, and reassemble.
Unfortunately, most wood slats only sit on top of the frame and are not fastened to stay in place. The potential for movement is huge and this can cause noises. Many companies add felt to the each end of the slats to provide a noise free buffer between the slat and the frame.
Best Metal Bed Slats
Best Metal Bed Slats
The best bed with metal slats is the SmartBase Super Heavy Duty foundation with 4,400 lb capacity.
- Metal quality
- Squeak and noise potential
The grid system is far supieror to the thin wires that only run in one direction or even the designs that use tube slats in only one direction. If you want to protect your mattress and avoid… voiding the warranty the grid system with retangular metal slats are the minimum you should be considering.
There is pretty much only one material used in most beds these days, an alloy. Gone are the days of steel and aluminum has always been too expensive (except we are using some aluminum components in our own Super Strong Bed design).
Obviously, the standard box spring frame is made from steel, but this is super rare with foundations that do not require a box spring (actually I don’t know of any, so let me know if you are aware of one here: Contact).
Width and Gaps
There are generally two types of bed frames with metal slats:
- Wire mesh/grid style
Most companies producing metal platforms for mattresses, rather than box springs, use a wire platform system with thin wire creating a grid or “slats”. This system is not suitable for many mattress models and will void the mattress warranty for many companies.
This is because there is very little surface to gap ratio and the wires can damage the mattress, especially foam models, when the mattress sags around the wires.
A few companies offer models with a heavier duty design where bars are used to create a grid, like this 4,400 kb capacity model
Bars are similar to wood slats except that they are thinner due to being a stronger and more expensive material. Due to this these bars are much more narrow. Companies say you don’t need a box spring, but check out this model and think about if the approximately 6″ gaps are going to be hard on your mattress!
If the above model has 0.5″ wide metal slats and there are only 11 of them to cover 74.5″ means that only 5.5″ of surface to support a mattress with a whopping 69.5″ unsupported. That means only about 7.4% of your mattress is going to be supported within the exterior frame.
Try putting a foam mattress on this model, sleep on it for a night, and please send me pictures of the indents in your back the next morning haha.
Squeak and Noise Potential
Metal bed slats are rarely the cause of squeaks and noise with beds made from metal. However, connections that are welded by poor quality craftsmen can result in grid style slats squeaking due to:
- Weak and failing joints
- Weak allioy metal
- Poor design that saves materials, but is not strong enough for some of us heavier sleepers (and late night gymnastic wrestlers).