Do NOT guess! Most SIP manufactures have span tables that will give you this information based upon the roof load(s) (don't forget to calculate the wind load)!
R-Control has an excellent span table and lots of designers use them. They will contain all the information you seek.
If you have other ques tons feel free to contact me off line.
Good Luck,
Matt B. Phelps, P.E., R.S.
TDI certified windstorm engineer and inspector |