Rain Screens: The Perfect Siding System for Seattle Homes

“It rains nine months a year in Seattle.”

“I know!”

– Sleepless in Seattle

Seattle is famous for its rain. But talk to a Seattleite about how rainy Seattle is and brace yourself for a discussion on raindrop size and inches of annual rainfall versus days of rain. Seattle doesn’t get that much rain, but as a local homebuilder we still like to be prepared for drizzly Pacific Northwest weather. One of the most important areas where homebuilding has evolved for wet weather is exterior cladding on a rain screen system.

In conventional homebuilding, cladding (siding) is nailed directly onto the weather resistant barrier (WRB) to keep out rain.  Over time, cladding materials break down and moisture can get trapped between the cladding and the WRB. Over time this can cause premature degradation of the structure.

Enter the rain screen system. The concept is simple: (1) Wrap the home in a breathable weather resistant barrier; (2) Create air space between the wall sheathing and siding with vertical furring strips; and (3) Attach siding onto the furring strips. (See infographic.)

Those furring strips act as spacers that create a gap where water can pass through if it gets behind the cladding. Instead of water getting stuck between materials that are tightly pressed together, we have air and moisture circulating and evaporating. The result is a wall that dries faster, prevents peeling paint, and is more durable.

We’ve adapted to the rain screen system in all of our homes at Isola. While Seattleites shun umbrellas and have great debates over rainfall, most locals would agree that rain screen system is a sensible, modern way to keep our homes dry while living in the Northwest. We know we are going to have rain, but it’s all in how you manage that moisture!