Unless you plan to raise the daybed, I advise not using a mattress higher than 7" (even though the instructions indicate the sliding bed can accommodate up to 8"). Assembly was so-so; the slats that the mattress sit on aren't very sturdy, and if someone accidently stands on the sliding mattress, I believe the slats will break. However, that said, for the money it's not a bad option. Just be aware that you're only getting "ok" quality.