I cant get a straight answer from the building inspectors around here (Louisville, KY) regarding the allowable span of a sistered 2 x 6 joist. I have done many attic renovations and I have spanned up to 13' with out a problem. The allowable span for a reg 2 x 6 by itself is 9'. There is a new kid at the inspectors office and he's giving me the run around on a attic renovation. Any help or websites you all could direct me to would be great. Thanks in advance.
is inspector giving you the run around, or is he telling you what you don't want to hear. if span is over nine feet, you say the 2x6 will work, but you also say allowable span is nine feet!!.
check out ONLINE SPAN CALCULATOR. it is true what brad says about species and grade affecting span.
by the way, have the past attic renovations been done on permit??
2-2x6 SPF #2 16" oc. sistered floor joist will only span 11'-8" with a 40# Live Load & 10 # Dead Load with a Live Load Defl. of L/360 & a Total Load Defl. of L/240. A single 2x6 SPF #2 16" oc. floor joist will span 9'-3" with the same criteria above.