valley rafter question

Code states, I believe, a valley rafter can be no less then 2 inches. Going by that, is a 2x10, that is really 1 1/2 acceptable. It is very rare to see it done any other way. I dont write it up but I do write up valley rafters that are not correctly supported at the tops and that I see all the time. thanks

Not sure what your standards of practice are however here in NC if you mention code then you have to cite the source and provide documentation; one way around that is simply put that the item in question does not meet acceptable construction standards and further evaluation would be warranted by a licensed general contractor.


The code states that a 2" minimum nominal thickness. Nominal means the name not the actual thickness. A 2x10 would be just fine depending on the length of the valley. I have had valleys with 2x4, 2x6 etc. depending on the roof specs. Since I am not a structual engineer I go by the plans.

Thanks guys, no I never use the word code I just use codes as a basis for my inspections. If we dont at least know the codes how do we know what is at least the minimum for building practices, we cant go by what we think is right. My other question was a partial valley rafter should be supported by a column down to a bearing wall or some type of system made to hold the weight correct. I searched for quit a while and could not find a section of the national code that states anything about a partial rafter and how it should be supported even though it makes alot of sense. Thanks

I know this post is getting old, and you may not still be looking for comments, but How do you mean partial valley rafter ? A partial should be seated on something, usually a doubled rafter acting as a header, no ? or am i misunderstanding your comment

There is a such thing as a Valley Jack Rafter which some people call a partial Valley rafter. A valley jack rafter is a valley spans between a ridge board and typically a common rafter…it has no seat cut or seat support; those should be supported with bracing below.