Buy Mattress Encasement Mattress Protector for Bed Bugs California King (Cal-King) Size, – Waterproof Secure 6 Sided Zippered Sleep Defense System – Allergy Relief Bed Cover Mattress Protector: Mattress Protectors – Amazon.com FREE DELIVERY possible on eligible purchases Buy Classic Brands Cool Gel and Ventilated Memory Foam 12-Inch Mattress, CertiPUR-US Certified, California King: Mattresses – Amazon.com FREE DELIVERY possible on eligible purchases This week I set out to ditch our box-springs and get low! Read more to find out how to build your own king sized platform bed. Please GO HERE for the updated 2015 king-sized platform bed plans! They’re BETTER! Because the instructions to build this bed are essentially the same as the plans for the Queen sized (including the bed frame), I will just be providing diagrams on how to build the Heaboard and Footboard in the king size. .