The frame itself is solid, but the slats are too far apart. We ended up sheeting the entire top with plywood and also adding 2x4 posts underneath in the middle of each side (we have the king) because there didn’t seem to be abough support. With the alterations it’s very solid and we’ve had great night’s sleep. Like others have said: you need to put a non slip mat under the mattress to stop the mattress down sliding around.