Originally Posted by Daniel Holzman
Concrete buildings with concrete floors are EXTREMELY DANGEROUS in earthquakes if they are not properly designed, as the floors have a nasty habit of detaching from the walls and pancaking the unfortunate occupants. If you plan to have concrete floors above the basement level, make absolutely certain your engineer is 100 percent versed in correct design. In an earthquake, it isn't the earthquake that kills you, its almost always the building you are in that kills you when it falls down.
Thanks for all the info!
The home will NOT have 2nd story concrete floors, it will have wood "I-Joist" floors and 1/2 the home will be open/vaulted ceiling.
The home will be slab on grade (no basement). I plan on utilizing a steel SIP roof. They are very lightweight but very strong. It saves $$ money because you eliminate the need to stick frame/truss a roof & you eliminate the need the blow in insulation or spray foam insulation.
It consists of 12" of EPS form sandwiched between 2 layers of steel. It carries on R-Value of R-51 and basically are laid on the ICF wall and on a ridge beam. They are then secured using long galvanized screws (8" - 12" OC) that go through the SIP and screw into the treated 4x12 wood that is sitting on top of that ICF wall. That treated wood is anchored into the concrete utilizing anchor bolts that were inserted prior to the concrete curing.
Here is some info on that:
PAGE#34 has a diagram of ICF to SIP attachment
It seems that a thin screw with a small head every 8" OC would still not be strong enough to resist wind uplift, especially if you had a 24" overhang. In high winds the roof would want to act like a sail and lift up off of the home.
Yet the engineers in that study claim that it will hold to 140MPH. I wonder if a wood truss roof would be stronger than a steel SIP in high winds or seismic? Have you ever dealt with steel SIP roofs?