My house is in CA (USA, we don't have many stroms / heavy winds) and i am undergoing a re-roofing project. House is about ~65 year old the current "plank decking" looks in decent condition.
Is it a good idea to put a OSB on top of it to make it a "SOLID SHEATHING" before putting the singles ?
My roofing contractor told that very few people chooses that option (1/100) or so.
Cost of adding OSB (solid sheathing) is ~20% higher (2K $). Is it worth the investment?
I already have adequate attic insulation and my question is primary related to longevity of the new roof.
Best Answer
What do you expect to gain by this?
Your roof deck is in good shape, so if you put a roof on it that keeps it dry, I'd expect it to stay that way.
Redoing the deck happens when you let the roof go to long, it leaks and rots the deck, and you need to remediate that.
If you are worried about meteors, they will not care about another layer of wood. I doubt you are getting hailstones of a size to break your roof deck, or it would be broken, and lacking some reason like that, I don't see much advantage to adding a layer of OSB to support your roof while it sheds water and ordinary size hailstones, when your current roof deck is doing that job just fine.