I have a 10 year old cal king sized mattress set. Is it ok to replace just the mattress and not the the box spring, especially if the box spring is in good shape? Does it make a difference if the new mattress is from the same manufacturer although the model may be different?
Hi hugo,
That will depend on whether you have a foundation (with no springs and minimal or no flex) or a box spring (with springs inside it that flex) and on the type of mattress you purchase.
There is more about the different types of support systems that are most suitable for different types of mattresses in the foundation post here and the posts it links to (in the second paragraph) but if your “box spring” is suitable for your new mattress and is still in relatively new condition and is still flat with no soft spots or sagging or weak areas throughout the surface, especially in the areas under the heavier parts of your body, (you can test with a straight edge to make sure its completely even and with strong pressure all over the surface with your knee to make sure there are no soft spots or weak areas) then it should be OK. I would also be aware though that some mattress manufacturers require that you buy their foundation as well to meet their warranty criteria so I would always make sure that using your foundation or box spring wouldn’t void the warranty.
Phoenix