Depreciation on roof repair?

I am a carrier adjuster working a unique claim where I have to work in tandem with a Nationwide adjuster. they rejected my estimate for a roof repair stating that I need to withhold depreciation on multiple line items. But this is a roof repair, not a replacement. we are replacing less than half the facets. At Allstate this is a repair and no depreciation is withheld. Does this rule vary from carrier to carrier? is it policy specific? I thought depreciation was just about universal in this regard. any nationwide people who can help me out?