# Do I need to add plywood sheating?



## roofnoob (10 mo ago)

I’m doing a complete remodel of my house with extension and a new second floor build up. The old roof (70yrs+) sheet are shiplap old wood that look to be very thin from this photo angle (red). 

GC recommends to add new 1/2” CDX plywood on top on the shiplap. It would cost me $15k to do that (I’m in HCOL norcal area).

I’ve attached some photos from below and top of the roof to show the conditions of the current old roof deck. Do you pros think I need the plywood layer? Thank you


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## roofermann (Jul 7, 2012)

If this were in my area and the boards are 3/4in thick, no. But some locales do require covering or replacing sheathing boards with ply/osb. Also the shingle warranty requires that there be no gaps between boards larger than 1/4in. Call your bldg. department and ask them.


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