Originally Posted by Jdmrenovations
what spacing are the rafters?
Excellent question. 2"x6" rafters are solid.,Depending on length and on center width and bracing.Close enough and 3/8" and 7/16" would be fine.Wider would require 1/2" or 17/32".
IMO a complete open overhanging/Carport structure is all the more reason for proper spacing.3/8",1/2" or 5/8" or more will buckle over time without proper spacing.That holds true for carports especially.Constant exposure to the elements.
Houses are built as one.One component handles the other and settling or movements of the structure have been figured by architects and the compatibility formulas are present and are used.
The problems with carports or porch overhangs is the after market effect.(Built by Uncle Buck on the weekends).Improper fasteners and length will also give the appearance of buckling when its actually seam pops.(The seams are nailed with inadequate number of fasteners)(Not enough)
The house shifts and is always moving and sometimes the carports or porches settle their own way resulting in twisting or shifting of the porch/carport against the houses movements.So binding and contorting of too tight of seams for the plywood is the effect from improper spacing.
Maybe a silly question to some.,but is the plywood running parallel to the gutterline?.,I have seen plywood ran vertical.Obviously wrong but it does happen.
How wide are your overhangs from the post points?.,Post some pix.Assumptions are a.,.,well you know.