Hi – working with a client who has access to old factory floor. It was true 2×4 floor and is glued and doweled with what looks to be 3/4″ hardwood pegs every 12″ OC. This floor was laid over 36″ OC beams. The floor was removed in 9′ x 4′ sections, every third board is solid 9′ length. They want to use this material in an entertaining space to create a mezzanine and they want to use as few beams as possible, ideally spanning 9′ and landing the end on top of a steel beam. Has anyone ever seen something like this used? Two engineers I spoke with don’t want anything to do with it because they can’t verify the glue used for construction nor the material. Where can we go from here?
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Commercial or residential?
Residential
So, this flooring was originally laid over joists scheduled at 36"OC. Your Client wants it installed to span 9' - 3X it's previous span. Load rating at 36" was probably different than its current proposed use. But by how much does that translate when applied to greater spans?
Can you test 3 panels and document/ film tests? Apply a load to center of span until panel fails or reaches equal/ double the load rating of a traditionally framed floor.
Frankie
I would imagine the loads are significantly different (40psf residential vs whatever it was originally designed for) I didn’t think of doing a film with a centered load. Theoretically measuring the deflection with a known centered load should allow extrapolation of the designed load given span. Or the load test film is enough to get the inspector off our back.... or it’s a film of our spectacular failure and need to use more supports!
This can be calculated just like a beam. For true 2x4 using 60 psf load the load on the beam is 4/12 x 60 plf. The width of the beam is 4”. The depth is 2”. From this the span can be calculated. My power is off so I can’t use my computer. You’ll have to use your best judgment as to the species and grade.