Foam-backed Vinyl Siding
Water Infiltration: Foam-backed vinyl siding installed directly over flat wall sheathing leaves no space for water to escape. Plus most foam backing is un-faced expanded polystyrene (EPS), which has a water absorption rate of approximately 4%.
Water Management Solution: Install a drainage wrap to move the water to the base of the wall. A drainage mat with thicker drainage channels is even more effective. Both approaches allow air movement in the space between the wrap and the siding to help facilitate drying.
RainDrop® Building Wrap is an ideal secondary weather barrier for foam-backed vinyl siding. It drains water and maintains space for air movement.