A split box spring is the foundation of the mattress that has two pieces placed side by side. It is essentially a mattress that can be folded in two and is perfect for a mattress that has to be delivered up staircases or through tight doors. King-size mattresses use this type of foundation because of their unusually large size that would make it impossible to bring inside the home.

Reasons for Using a Split Box Spring

So, why use a split box spring? The box spring is the foundation of the mattress that is created to work together with it. It is this foundation that takes on most of the pressure applied on the mattress and supports it. It creates a firm structure that the mattress can be ideally flat upon. Besides its ability to absorb the shocks that are placed on the mattress, it also raises the bed high enough so that you can get more conveniently in and out of bed.

Ways to Select a Split Box Spring

Now that you know why to use a split box spring, you have to have some idea of how to choose the right product for you. Here are some things to know when choosing a box spring that will match your mattress perfectly.

Consider the Bed Height

Box springs add height to your bed. To make the correct height, you will have to consider both your mattress and box spring height. Most box springs measure 9 inches or 5 inches. As more mattresses are created thicker for more comfort, a 9-inch box spring will make a very tall bed. If the mattress is already tall, look for a shorter box spring. Smaller box springs provide the same support as taller ones.

Select the Materials

Box springs can be made of different materials. For the most part, it is the material of the box spring that can make a difference in the prize. Depending on your considerations, you might want to look into box springs that have hypoallergenic or organic fabrics as well as natural fillers. The springs and parts of the box spring may also vary in the materials used.

Why Choose a Split Box Spring

Unlike a whole box spring, split box springs are made of two pieces that are easily folded together and moved through tight spaces. The two pieces of the box spring can also be taken apart and carried separately making it a much lighter task to move the whole thing from one place to the other. Split box springs are usually lighter than the whole box spring model. People who frequently move from one place to another, those who prefer more height to their bed, those who want extra durability, and those that want more bounce to their mattress will benefit from this type of spring box.

Downsides of Split Spring Box

Although the split spring box is just as good as the traditional ones, there are some downsides to this model. Because of the fold, there is going to be a slight gap in the middle of the mattress where the two halves fold. Of course, this depends on the model and the prize of the spring box.

For someone who is a very sensitive sleeper, this detail may annoy them at night. Although the gap is underneath the mattress, some may still be able to feel the gap. People who are restless sleepers and toss a lot at night should also probably steer away from split box springs since too much movement at night can shift the halves and make the mattress shift as well. This could also cause the sheets to shift. If the downsides are too much then we it would be worth checking out Asizebeds homepage for alternative options.

Why Use a Split Box Spring

Besides all the benefits of having a spring box, it is a great idea to have a spring box for your mattress because many modern mattresses require a box spring for their warranty. Most companies want to have this standard for their mattresses because setting the mattress on an uneven or poorly supported surface can contribute to a shorter lifespan. This way, companies know that any warranty claims do not come from a lack of proper mattress support that would otherwise eliminate problems and prolong the mattresses lifespan.

Best King Size Split Box Springs

Here are the five of the best king size split box springs that you can choose from.

Mainstays Half-Fold Metal Box Spring

This half-fold box spring is great because it is a design that does not contain fabric. This makes it naturally resistant to bed bug infestations and mold growth. The box naturally folds so that it is easily stored and moved. Because of its black classic design, it is great to use with any room decor. The steel bars that make up the box spring are easy to clean and can withhold a very heavy mattress. The box is easy to assemble and has a coverlet that does not slip off the frame. It can be removed, washed, and dried quickly.


  • Strong, steel design
  • The classic design matches most room decors
  • Does not collect mold or become a breeding ground for bed bugs
  • Has a removable coverlet
  • Easy to clean
  • Design that is easy to fold
  • Lightweight
  • Makes no noise


  • The cover can be hard to put on at first
  • The assembly can be hard at first
  • Some products can be a little squeaky

Mainstay Classic Premium High Gauge Steel Black Finish Half-Fold Metal Box Spring

This king-sized box spring is 80″ x 76″ x 7.5″ and has a weight capacity of 2400 pounds. It is made of high gauge steel, polyester, and plastic. The spring is made to be naturally resistant to mold and bed bugs. The box folds in half so it is easily stored and hidden away when not in use and easier to move through tight spaces. The black finish of the frame makes it good for any decor. The coverlet can be removed and washed with the laundry.


  • Heavy gauge
  • Steel bars
  • Easily folded
  • Compact and flat when folded
  • Easy to clean when cover is removed
  • Non-slip surface
  • Requires zero assembly


  • Could use more bars for extra support
  • Frames not wide enough for some mattress models
  • Cannot exceed the recommended weight limit

Zinus Victor 9 Inch Quick Lock High Profile Smart Box Spring

This box spring is good because of the densely placed steel slats that are less than 3 inches apart. The packaging makes it easy and quick for construction because of its quick lock construction. The 9 inches of height makes it a good fit for a low-height mattress. The steel frame has foam-padded tape to reduce and eliminate noises when used. The item weighs 60 pounds and has dimensions of 79 x 75 x 9 inches.


  • Foam-padded tape to stop squeaking
  • Made to be assembled and constructed fast and easy
  • Sufficient height to compensate for low mattresses
  • Dense steel slats for greater support


  • Too firm for some users
  • Cover hard to zip

Zinus Edgar 8 Inch Profile Wood Box Spring

This mattress foundation is for the ones that prefer a wooden box spring instead of a steel one. The wood mattress support is still sturdy but more gentle than steel box springs. This one is created to be assembled in a matter of minutes. Because of its wooden frame, this box spring is lighter than the other ones and easier to maneuver with throughout the home. People who are constantly rearranging their furniture might benefit from this lighter design. The height of this box spring is 8 inches, which makes it perfect for short-height mattresses. The weight of the item is 54.6 pounds.


  • Lightweight
  • A softer, wooden frame
  • Tight slats of the wood frame
  • Sufficient height to compensate for a short mattress
  • Easy to assemble


  • Compromised strength

NOAH MEGATRON 7 Inch Heavy Duty Metal Box Spring

 This box spring is made to evenly distribute the mattress weight on its surface. The fabric of the cover is made of microfiber and is resistant to shrinking and wrinkling after washing. The model was created to be noiseless when getting in and out of bed. The easy set up of the box spring requires less than 30 minutes of assembly. The king-sized bed is 7 inches in height which makes it good for both high and low mattresses. The mattress weight a total of 48 pounds.


  • Very lightweight
  • Stainless steel frame for durability
  • Easy to assemble
  • A moderate height of 7 iches
  • Cover is made of an easy to maintain fabric


  • Cover is sometimes hard to fit

The Best Choice

All of these products are good because they cover the basics of a split spring box. They are all easy to use and transport inside your home through tight staircases and doors. Undoubtedly, the one that is most preferred is the Mainstays Half-Fold Metal Box Spring. It is easy to use, has a strong and sturdy construction, and is lightweight. Because it is made of metal and a washable cover, it is hygienic for usage and does not collect mold or promote a bed bug infestation.