Can I cut a king-sized mattress in half to create twin beds?

No, definitely not!!

mattresses have a stronger outside edge, if you cut it up you will loose this, buy 2 new mattresses

Do you have a bed frame you are planning to use for him? If so, then buy a new mattress or *my idea* place a piece of plywood, just large enough to cover the frame and 'make' a mattress. The material list can be as long or as little as you like. I usually have plenty of old ripped comforters and blankets. I would fold until you have the size you like. Tack with needle and thread around edges as you add. Occasionally, tack some where in the center. (Try not to tack center the same place each time). When you get to a 'thickness' you like, then sew a cover. It doesn't have to be fancy. I would use an old flat sheet from your bed. Good Luck!

No; cutting a mattress up will destroy the edges of the matterss that make it strong; and will crete a huge mess. You are better off in trying to find soemthing through freecycle or purchase a new one. foam core twin size mattresses are not tht expensive, unless he is a large kid; then you will want to invest in a regualr twin mattress

I once had a (really good) foam mattress cut from full to twin. It's a bit messy. We peeled back the mattress cover, cut the foam with an electric saw, and then immediately secured the cover underneath for the smaller size. We put a sheet of plywood underneath the mattress. The mattress lasted about five years on the twin platform. I don't think you can do this with a traditional mattress. Good luck!!

tyty. Just trying to get by :) appreciate your time. Happy New Year!

Fabulous Ideas, Glenda. He is 6'1" and it is gonna be a stretch to put him on a twin. Money is almost none since the hurricane and the box springs on the king are 84" Not sure they even sell twins that long .... sigh. Appreciate your help and Have a Happy New Year.

my husband once had a very large art studio and he wanted a bed there. He made a plywood bed and got a long piece of foam for it. Wish you were nearby I'd love to give it to you! We bought a second hand single bed recently for only $25. You could tell the mattress was clean. I would try Craigslist or something like that.

There are extra long twin bed mattress's out there. When I was in college way back when, that is what they used in the dorms. Every fall it like everyone is advertising the extra long linens. These are made for the longer legged people out there. I know that a lot of the semis that my hubby has driven had the extra long mattress's

try Goodwill or any other used furniture store.

Generally no, you cannot cut the mattress unless it is foam. If it is, you can use an electric carving knife to do that. These are usually found at flea markets.