In that our Scottsdale residence is a 2-story structure, it was an obvious choice to configure our log home in a similar fashion. Our desire to maximize exposure to the dramatic views and visions of a monumental staircase certainly helped cement the 2-story concept. The obvious function of 2nd-floor framing is structural…..plus a whole lot more.
With a plethora of available framing options, we elected to use 9 1/2” deep I-Joists 16” O.C. for their structural efficiency, ease of erection and economy. We over-designed the sub-floor with 1-1/8” T&G plywood sheathing (my framers were not thrilled as each sheet weighs ~90lbs).
The ‘whole lot more’ of what ‘lies within’ gets to be an exercise in precise coordination. Plumbing drain-lines take precedent having to land directly under the fixtures while maintaining minimum slopes. Fire sprinkler pipes are not slope dependent but must be isolated as the CPVC piping material will degrade from being in contact with certain plasticizers in electrical cabling, foam insulation, etc. (A little know fact not even my building inspector was aware of.) The rest of the systems are not quite as demanding albeit the refrigerant lines for our 5-zone mini-split system are not overly flexible and can kink quite easily.
LESSON LEARNED: I’d dial up the TJI depth a notch to 11 7/8” providing a few more inches for the systems.
