11/29/2017
Why does my wood siding melt?
"In wet climates, house wrap sometimes reacts poorly with certain kinds of wood siding. Lignin (a naturally occurring substance in many species of wood) is water soluble and acts as a detergent. Like all detergents, it decreases surface tension and destroys the house wrap’s ability to repel water. Research has shown that wood lignin makes it easier for liquid water to pass into the wall. Certain types of wood siding, such as redwood, cedar, and manufactured hardboard siding, seem to accelerate the problem. To avoid this problem, carefully attach heavy building paper (30-pound asphalt impregnated) to the walls as a substitute for house wrap. You also might consider installing felt paper over the house wrap as a water-repellent surface."
https://www.hometips.com/buying-guides/insulation-air-barriers.html