Hello,

Was wondering what some of the more experienced folks do in this situation.

House is about 25 yrs old with 12″ hardboard lap siding, double pane alum windows, and celotex sheathing. 

The siding directly above the windows was rotten from water collecting on the head and weeping back behind the siding.  I am a self employed contractor/handyman, and was asked to repair the siding.  AFAIK, there were no issues with water getting inside the house or leaky windows.  (House is a rental with out of town owner, tenants are never there for me to get inside and look)

The owner had  requested that I replace siding lap above the window only, as that was the only one that was visibly damaged.  I typically make repairs like this using peel and stick flashing (Protecto Wrap or similar) over a z flashing, and then install the siding.  

This is the first time I’ve ever had to do this on a house sheathed with celotex.  My question is, will the peel and stick flashing do any good here? Or is it pointless?

Thanks for the help

David