Kojak:
We are removing the existing painted spruce trim and then will install painted 1" thick smart panel trim. The trim will attach to the plywood subsiding on the house and the existing hardi plank lap siding will butt up against it. The caulk will be used to fill any gaps between the windows and the trim and between the trim and the lap siding. The 4" face of the trim will be exposed to the weather as will a small portion of the edge of the trim where it butts up against the lap side.
