An improper base is anything that is flexible or does not provide enough support for the mattress. The result of the mattress being used on an improper base includes sagging, dips, or indentations. Issues with the mattress caused by being used on these types of bases voids the warranty.
Examples of improper bases include:
- Box springs with wires, coils, or thin metal bars
- Slats that are arched/curved or spaced more than 4" apart
- Platforms with thin metal bars (most commonly in a grid-like pattern)
If you plan on using one of these bases, you must add a solid board, like plywood, on top. The plywood should be 1/2" – 3/4" thick and cover the entire surface of your base.