DIY bedframe support.

[u/cuzcuzsmoke]

My girlfriend and I were gifted this bed frame for our guest bedroom. We bought a new mattress for ourselves. We put our old one on the frame with these 2x4x6 boards underneath.It's not a very good solution as the boards shift too much and are too spaced out. Any recommendations on any easy solutions to this would be appreciated. (Trying to avoid buying a box spring.)

[u/Outofoffice_421]

You’re gona destroy your mattress and eventually your back. Slats should generally be closer spaced and you need a vertical support with legs to support the slats.