i have a 14x50 mobile home with shingles and want to go with metal. My question is do i have to put down 1x4 boards or can i screw down on top of the shingles? also im wondering if there is a heat factor difference with boards or not? im planning on ridge venting the full length of the home.
The proper way is to remove the shingles, otherwise the metal might not lay flat. If you are going to leave them it would be best to use 1x4 strapping so you have something solid to screw into (especially around vent stacks and other projections).