I'm not a stairbuilder, but I am designing and planning go build this staircase for my upcoming house. See the image and attached Sketchup file.
It's open riser stair, with a set of 4x4 columns on one side as stringers, and a regular 2x12 stringer setup on the other side. Span between the two is 39 inches. Trying to build frugally but good.
First question. I've hit upon the idea of getting a bunch of IKEA's 1-1/4" thick beech butcher block counter tops and cutting them up as treads. I'm no engineer, but does anyone have an opinion as to whether this is a suitable thickness and material for a tread with 39" span, supported only on the ends?
Next, as you can see from the illustration, each tread is drilled out with a bunch of 3/4 inch holes to allow light to pass through. Would these holes impact the above mentioned concerns about flexing of treads over that 39" span?
Finally, what's the best way to fasten the treads to the stringers. Some architect said I should just get underneath and drive some screws in, pocket hole fashion. Ewww! That seems kinda unkosher to me. How does the real high lama stair builder do it so that the stair is bomb-proof.
This staircase cannot be trial-assembled in the shop, it's gotta be built on the site (since the 4x4's are structural).