Right now he is wearing both the tab diaper type and pull up at night. He can still wriggle out of them just enough to make them ineffective. We do slightly better during the day. My floors are covered with canvas drop clothes and my laundry is ridiculous. I dread this winter and additionally washing a blanket every morning. I would appreciate any suggestions.
I'm pretty sure you can buy a vinyl gel mattress topper to fit whatever size bed he sleeps in. Then you won't have sheets to do.
Mom sleeps under a washable quilt. It seldom gets wet, but I have a matching one so I can wait a while to wash the soiled one.
These briefs hold over a quart of liquid. If he's losing more than THAT at night, yikes.
http://www.yourdiaper.com/adult-diapers-atn-disposable-brief-p-331.html
If it's because he's taking them OFF during the night, try these one-piece zip-up-the-back PJ's. $42 (Buy two pair; one to wear while one is laundered.)
http://www.buckandbuck.com/mens-clothing/sleepwear-and-robes/sleepsuits/mens-two-tone-back-zip-sleeper-suit.html
Good luck. I hope at least one of these is helpful.