Foam Mattress Bigger than Boxspring

Discussions General Mattresses Questions
1

I just bought a new sleep options cool gel 9" mattress set (foam mattress that has a cool gel layer and a box spring). Both the box spring and the mattress are full sized, but the mattress hangs over the box spring by about 2 inches.
Can someone tell me if that’s normal? do you think it will damage my mattress to hang over the box spring that much?

thanks!

2

Hi Emily12345,

Box Springs are often just a little bit smaller than a mattress but a 2" difference is a little larger than the norm.

If it’s in the length it’s not likely to be an issue unless you sit on the end of the bed and if it’s in the width it’s also not likely to be an issue unless you sit on the sides or sleep very close to the edge of the mattress.

Phoenix

3

thanks for the info! it’s 2 inches wider, not taller. I guess if we centered the mattress on the boxspring it’ll only be 1 inch on either side.
Is this normal for a foam mattress? the person who sold it to me said that foam can grow/shrink 2-3 inches depending on temperatures.

thanks!

4

Hi Emily12345,

Full size mattresses are typically 53" or 54" wide depending on the manufacturer and a typical mattress can have a size variance in the range of 1" in either dimension (because you are dealing with soft materials that can stretch or be compressed).

Foundations are also made in the same widths and will often be a little bit smaller so that they fit into the bedframe.

With all the variances … it would be inside the range of “normal” that you have up to a 2" difference between the mattress and the foundation.

The Classic Brands (Sleep Options) full size 9" gel mattress is “supposed to be” 54" wide (see here).

The Classic Brands instant foundation is also “supposed to be” 54" wide (see here) but they may have sent you a different foundation.

I don’t believe that a memory foam mattress would vary 2" to 3" with temperature although the sides of a mattress can “bulge” as the material compresses or over time.

It would be interesting to know the specific dimensions of your mattress (top edge to top edge) and your foundation to see how the measurements compare and which one is either narrower or wider than the “standard” measurements but if you center the mattress over the foundation and there is only an inch overhang there shouldn’t be any issue.

Phoenix