My goal is to make hardwood slats for a 4' wide bed, (center support, so span is 24"), thin enough so my heavier parts flex, adding comfort so I can minimize mattress. (Ideally, pad will be 1 inch cork, a nylon 'Persian-style' rug, and a very thin bed futon. I am thinking Japanese style bedding, minimal cushion. It needs to be thin to flex under my weight, but not so thin that ot causes degradation that excessively shorten it's life-expectancy.
I saw the swing discussion, and thought about the International Council of Building Officials books, and tables that I used 40 years ago to determine thickness of joists and rafters for given spans, dead or live loads, pitch, etc.
I found a series of tables for hard and soft woods in a PDF download, I don't have the link, but it is titled, "Chapter 4, "Mechanical Properties of Wood," by David W. Green, Jerrold E. Winandy, and David E. Kretschmann."
I am struggling to grasp the understanding of the data. If someone would like a look, I think I can attach it to an email & send it.
Back to my problem: I am thinking of going with 3" wide ash stock, ripped to 1/2" to 5/8", to span the 24". I would like the board to flex at my shoulders for instance, to cause the bed at my shoulders to support an equal amount of weight as my abdominals for instance.
Best Answer
IKEA sells slatted wood bases for beds. The Luroy model is the most basic where “16 slats of layer-glued birch adjust to your body weight and increase the suppleness of the mattress”.
I’m not quoting them as an advertisement but just to give an example solution. (Although, you should consider whether the double/full at 52 3/4” wide could be used or modified to suit your need.)
Perhaps you don’t want to tackle layer-glued wood to start with a bend. Straight hardwood works but is going to be a little less springy since you will have to make it thicker to avoid rolling towards the center.