Updated February 22, 2021
When shopping for a new mattress, you may be considering whether you should buy a new box spring (foundation) as well. Or, you may wonder if it would help to replace your box spring periodically regardless of a new mattress.
It's not always necessary to replace your box spring every time you replace your mattress, but it’s probably a good idea to do so. Box springs do wear out at a similar rate as mattresses. Box springs usually last around 10 years, which is a slightly longer lifespan than the typical mattress.
If a box spring has any major defects like broken slats or noticeable sagging, it won't provide adequate support and you will need a new one. Worn-out box springs can cause your new mattress to sag sooner and create discomfort. Mattress warranties will often be voided if you use a box spring that's broken or sagging.
To learn more about the purpose and features of a box spring, read our explanation here: What is a Box Spring?
You do not have a box spring or platform bed appropriate for your mattress
Your current box spring has broken slats
Your current box spring has noticeable sagging
You’ve already had your current box spring for 8-10 years
So, what is a box spring? A box spring (also known as a foundation) is a wooden frame that uses either springs or metal rods to provide a supportive base for the mattress. The box spring should be the same size as the mattress that sits on top of it. It ensures that there is a flat, solid surface to act as a base, reducing sagging and extending the lifespan of the mattress. Box springs also absorb shock to reduce wear on the mattress itself. Box springs will raise the height of the mattress. If you prefer a lower total bed height, low-profile box springs give more options.
If you're wondering whether you really need a box spring for your bed, check out this article: Do I Need a Box Spring with my Mattress?
In a complete bed set, box springs are typically placed on a bed frame that connects to the headboard and footboard. It's also common to see mattresses and box springs used together without a complete bed frame. Those who don't feel the need to have a decorative looking bed can simply place their box spring on the floor or on casters, with the mattress on top.
With large mattresses, like a king-size, the box spring can be difficult to maneuver through tight spaces in your home. In this case, it may be beneficial to purchase a split box spring, which is split into two halves.
Most manufacturers require you to support your mattress with a box spring in order to file a warranty claim. There are exceptions if the mattress has approved box spring replacements. One example is mattresses that work with a platform bed. Since platform beds feature either wooden slats or a deck, the mattress shouldn't need the added support of a box spring. Adjustable bases are another possible option.
For options other than a box spring, check out the Alternatives to Box Springs article.
If you're unsure whether you should buy a box spring with your new mattress, or you have questions about a certain box spring, give us a call at 1-800-455-1052. One of our friendly mattress experts will be happy to assist you further.