I have a new roof in progress and am putting the insulation on top of the roof deck. I’m still waiting for my screws to arrive but I must waterproof for snow (the budget for screws is almost as much as the metal roof :)) and rain. I plan on putting 30lb felt over the 7/16 osb until my screws arrive and then add 6″ foam and then a layer of 1/2 OSB, then the metal roof. Do i need to remove the first layer of felt before adding the insulation or just leave it? Thanks