How thick of mattress fits before not having any siderail support left?
1299233
We have a standard mattress on there (no box spring) so my son has probably at least 6 inches of the guard rail above the mattress which seems to be enough. My guess is if you also had the box spring there wouldn't really be any guard rail above that.
1299234
I just used a regular twin size mattress from the twin bed we already had, and it works great - no issues.
367634
I put an 8 inch mattress on the trundle, with sheets and a comforter still on I can put the trundle away easily. I wouldn't get thicker than an 8 inch it may not fit easily
1705205
I have a 12 " thick foam mattress in mine. It is separating and the slats are not held in place any more. Bad quality.
897088
Think thin. You need a bunky board underneath the mattress and if the mattress is too thick it will be above the rail and therefore unsafe.
2220768
The frame actually sits over the box spring so the thickness of the mattress shouldn't matter. This has been a lifesaver for my mother and huge piece of mind for me.
874122
I use a full size 8" mattress. Remember if the mattress is too tall it'll be higher than the railing.
674162
We have a pillow top mattress & it fits a little loose. The mattress we have is almost 11"'s thick. I hope that helps. We got two, one for the mattress & one for the box spring. That seems to have helped a lot. Once we got the frame rails cleaned up. We also bought the sticky traps if any are hiding in the carpet.
1020571
Mine is much thicker than that. Since it is inaccessible right now (it's in long-term storage), I can't give you an actual measurement, but I'd guess it is at least 4.5" thick. I find it firm and yet very comfortable.
1146393
I am sorry, it has been so long I don't remember. I can say that I had two twins to support an 18" king mattress that was very heavy. I gave the bed to my mother, and the box spring covers are still intact like almost new.
576646
The sides are quite deep..it fits very securely and hugs around and under our mattress. I believe that if you did have a zip on mattress cover it would still fit well. I hope that helps answer your question.
494985
Our mattress is about 18 inches thick... 6 inches would be too thin and would not provide enough support, I don't think.
1104709
There is an inch lip surrounding the frame keeping a standard twin size mattress in place
610887
This works fine for thick mattresses. My only problem was that the mattress was below the frame line which made it impossible to lower the rail to easily change the sheets.
1022843
The mattress is ABOUT 4 INCHES thick. I do not suppose it would conform to a non-flat surface. Just a guess on my part. Otherwise, a great sofa mattress replacement.
2243922
It is flat and just goes on top of the bed and not over and around the corners, so it will fit any thickness of mattress.
1626916
The thicker side is the base foam side and should be down. There is printing on one of the edges that guides you as well. I didn't see it until about 2 weeks after I set the mattress up. Hope that helps.
335246
If you have a mattress with box spring, then you're all set. What's deceiving about the pic is the support rails along the side. That is not included.