Re-roof Question

Home built in 1914. Rafters 3-4 ft apart. Rafters have battens running across them with a metal roof for the covering. Client hires a roofing company to replace the metal roof with another one. Roofer says the battens need to come off and 3/4 inch plywood deck should be installed before the new roof covering. The local AHJ says the battens should stay and just put the plywood over the top then the new metal roof. To me I would think the plywood should be directly on to the rafters. Now I know as far as a wind mitigation is concerned it would not matter because the rafters are to far apart. Just looking for opinions. Thanks

Experts have said their piece .
I would try to say nothing more.

I am done talking, they can do what they want. I told the owners to get everything in writing and save it forever. I was just curious for my own mind what others thought.

The code allows adding the plywood over the battens. Removing the battens would require engineering, and possible adding support rafters due to span.

Thanks Brad.

Good info Brad Thanks

I had a similar situation and I don’t remember where I found the thread but Jerry Peck’s stance was the battens had to come off and the sheathing applied to directly to the trusses…he spelled it out like he typically does and I could see his point…

I have seen numerous instances where the plywood was nailed on top of the decking. It is also nailed to the battens to keep it flat. I suspect it is up to the AHJ and what he says.

I have always wondered, why, after the roof covering was removed, the spaces weren’t just filled in with 1 x 4 or 1 x 6 wood?
It seems to me, that it would be easier and you would have a stronger deck for whatever roof you wanted to install.