Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: What size should I get if my mattress is queen size but only 8" thick (no box spring)? Memory foam mattress.
Document: We have no box spring and have only a Cal King size memory foam Serta mattress. So this thing is both floppy and HEAAAVVVVYYY. It was SO hard to get this product on our mattress. That isn't even the worst problem. For whatever reason, it is not easy to tell which way is to be the top, bottom or sides so when we started to put it on we were half way up the heavy mattress before we realized it didn't seem to fit the mattress the way we were putting it.
This was a lot easier to get onto my double-mattress situation than we expected. I have a 4&#34; memory foam on top of a thick California King mattress. First we unzipped the two halves of the new pad. We rolled up the memory foam and removed it, stood the mattress on its side, and placed the bottom half of the new pad on the box springs.
My girlfriend and I purchased this protector for our Sleep Innovations 10" Sure Temp Memory Foam Mattress (Queen) as an extra line of defense for the brand new mattress. The product was delivered two days early, it was packaged perfectly and was very easy to get out of the box and onto the bed.It took us a few minutes to orient the protector correctly but part of this was due to the difficulty of manipulating the memory foam mattress enough to get the protector underneath it.
Good quality material. Easy to install. Big enough for a thick queen mattress and 2 inch memory foam. Have not slept on it in the summer yet or had a cat pee on it so am not sure how it is under those situations. At this point I would definitely recommend it. If it doesn't hold up I'll write again later.
To finish, I tuck the remaining fabric under the mattress. I have a 10&#34; memory foam mattress, and there is ample fabric for thicker mattresses... possibly box spring AND mattress together.Overall, I love the cover... The only reason I have 4 stars instead of 5 is due to the price. I do agree that the quality is pretty good; however, I still believe that the price is a bit much.
Very ample size--I have a mattress, egg crate foam topper. & a memory foam 2" thick topper encased in it & still have more than enough room. It doesn't crinkle & make noise like many do. I haven't had the cover long enough to put it through a washing/drying yet so if I encounter any problems with that I will revise this review. With mattress sets costing thousands of dollars this is a very wise & economical purchase.
This mattress protector fits our very thick extra plush memory foam mattress with ease. I was nervous to buy a protector online in fear that it would not be a big enough width but it claims to fit every size mattress and sure enough it did. It is well made and I can see it lasting for a long time. I bought this protector specifically because it encases all sides of the mattress including the bottom and it works wonderfully.
This is the third brand of mattress protector we have tried. Love the fabric - it feels very nice, cloth-like and quiet. Also love the six-sided zipper style - makes it easy for washing just the top side of the mattress protector. However, this mattress protector is way too generous in size. We ordered the regular Queen size. We were able to encase both mattress and box spring in a single mattress protector. It fit both the box spring and mattress perfectly!
I bought this for a Natura brand latex mattress, which is only about 8" high, that I combined with a box spring that was about 10 inches high. This cover managed to contain both the mattress and the box spring (a bit tight, but it did fit).
I wanted a zippered waterproof mattress protector for my new mattress. It fits my queen size bed just fine. It is a little baggy, but would be good for larger/thick mattresses unlike mine. I also never washed it, so it may shrink a little. But it zips completely close and there is no noise made from the material. Exactly what I was looking for. Would buy again!
Answer: Buy the one that is for the box spring same encasement but for smaller size up to nine inches and the cost is much lower.