This is called, from what I’ve read, a Kentucky Stick Chair. I was told about it from a Lumberjock buddy, Eddie. He told me where to find the plans over at the BuildEasy website. You can view the instructions for free, or purchase a PDF copy of the plans. I suggest the purchased option. It’s only five dollars and the PDF version is simply easier to carry to the shop with you to have on have to reference to.
They are surprisingly easy to build. They consist of three two by fours ripped into sticks and various hardware to hold it all together. I made two. I made one out of yellow pine that I treated with Thompson’s Waterseal. Then I made one from pressure treated pine. The yellow pine one is light enough to carry anywhere. You can carry the pressure treated one, but it has a little weight to it, so it may not be suitable for you beachgoers out there.
They are surprisingly strong. They are also comfortable. When I first seen them, I must admit I was a little worried about these two things. Once constructed though, they will make great lawn chairs that everyone will like and will hold even a heavy man like myself.