Box spring vs. foundation: What you need to know

Box spring

When you’re purchasing a new mattress, you’ll have a variety of box springs or foundations to choose from based on the mattress brand from which you choose to purchase. (Not sure whether or not you even need a box spring? Click here to check out our advice.)

The right box spring can actually improve the performance of your mattress, so it’s important to understand what to look for. Let’s take a look at the most common box springs and foundations.


Real, flexing box spring

A real flexing box spring acts as a shock absorber for your mattress. These box springs can help improve the long-term comfort and durability of your mattress by absorbing some of the weight placed on the mattress.

Most mattress manufacturers used to make this style of box spring. But over the years, the mainstream brands made major cuts to quality in order to cut costs. They moved to rigid foundations and platforms, which offer no shock absorption and therefore no direct benefit to the mattress.

OMF still manufactures real flexing box springs. From our good-quality starting line to our highest-quality premium lines, all of the box springs you’ll find here are built to improve the comfort and durability of your mattress.

A flexing box spring can come in different designs that offer different benefits:module box spring

  • Module: Shock-absorbing modules absorb pressure, reduce wire fatigue and side-to-side sway, and increase durability. This design provides a good balance between shock absorption and stability. This is the design that we use in all of our standard box springs.
  • Coil: Shock-absorbing, cone-shaped coils deliver a softer feel than a modular style box spring and are typically used by hotels due to their ability to resist abuse. The design results in more side-to-side sway and motion than a modular box spring. We manufacture these as custom orders.

How can you tell if the box spring is a real, flexing box spring? When you sit on the edge of the mattress, you should be able to see the box spring flex a bit in response.


Semi-flex foundationsemi-flex foundation

The term “semi-flex” is a bit misleading because these foundations offer no shock-absorbing benefits. If you’ll excuse the dad joke, we always say that it would take a semi to flex these box springs.

A semi-flex foundation is a zero-deflection, straight-wire cage with no shock-absorbing benefits. The semi-flex foundation was originally developed by manufacturers to compete against low-cost wood platform foundations found in low-end products. Today, this type of foundation is used by most major manufacturers in products of all quality levels.


Rigid platformplatform box spring

This style is typically a low-cost, zero-deflection platform that is typically comprised of a wooden or plastic box covered with cardboard and fabric. Like a semi-flex, a rigid platform isn’t going to provide any direct benefit to your mattress. And depending on its quality, it may not even provide adequate support for your mattress.

You’ll often see a version of this rigid platform (with assembly required) sold by online bed-in-a-box companies. Real box springs — or even semi-flex foundations, for that matter — cannot be shrink wrapped and stuffed in a box, so they have to send all-wood rigid foundations that can be assembled by the customer at home.


Which box spring is right for you?

A new mattress is a big investment. You want to make sure it lasts as long as it can. The right box spring can help. For that reason, we’ll always recommend that you pair your new mattress with a new, flexing box spring. A real, flexing box spring will help you get the most out of your mattress for years to come.

Ready to start your mattress buying journey? Come to The Original Mattress Factory first. No one knows more than our team about what makes a great mattress great. Whether you buy from us or not, you’ll be better prepared to make a smart mattress buying decision. Find a store near you.