opposing rafters

[rfigueroa]

I inspected a house today that had different sized opposing rafters across the ridge board from each other (?). Is this allowable? Or do they have to be the same? I will post a picture.

[mnahrgang]

Well, regardless if they are supposed to be the same size (they are), you've got to ask yourself why are they different? Maybe part of the roof was replaced. Maybe some of he rafters were replaced. Why would that be? And while we are asking why, why is there white paint on the underside of the rafters and decking? Sure seems like there might have been some sort of damage from something (maybe a fire) that has prompted these changes to the house....

I'm just guessing, based on two pictures, but I'm leaning towards the smaller boards were original, the bigger boards were the replacement, and there was a fire (first picture the decking looks very dark under the paint.

BTW on the second picture, you have plywood decking and the first picture is OSB. Again, why?

[Paul Pendley]

um...I would be more interested in why there is paint in the area....That usually means fire or moisture damage.

[Christopher Currins]

Basically what Mark said.

[Paul Pendley]

Its more like a primer that kills the smoke/mold stuff. Seen this twice in 3 months now. Buyers had no Idea....go figure.

[David A. Andersen]

Looks like low e paint.

Would help to know where the house is.

[rfigueroa]

Sorry, I should have included information about the paint. The paint is a radiant barrier type that is commonly applied if the house was originally built without radiant barrier type roof decking. There is no evidence of fire.

[Jeffery L. Haynes]

Over sizing rafters have no impact on one another however under sizing does have an impact, without knowing the clear span it would be difficult to answer your question.

Depending on the age of the home what may come into question is when the top cut of a rafter exceeds the ridge board.

I did note that both OSB and plywood is present which could possibly indicate that repairs were made at one time.

Jeff