Washington state has two basic climate types: coastal and continental. The Cascade Mountains serve as the big divider between these two distinct sets of climates, with the western side of the state being predominantly coastal-type and the eastern side being predominantly continental-type. Latest Reports have covered how to choose the best roof for Washington’s coastal communities, which lie on the western side of the Cascades, but how about the Cascade mountain region and eastern communities? The Pacific Northwest’s roofing needs vary by climate type, especially considering the effect the Cascades have on homes.
Typical Climate in the Cascades & Eastern Washington State
About 90-125 miles inland, the Cascade Mountains serve as the main climatic barrier that separates Washington state and produces a vastly different climate between the eastern and western sides. This mountain range captures most of the rain and moist air from the Pacific Ocean that would otherwise fall onto the eastern part of the state, while the Rocky Mountains shield the region from Canada’s cold air masses. This creates a large inland basin for most of eastern Washington, creating a rain shadow effect, where the amount of rainfall close to the summits is less than what’s experienced as you move eastward. Also, the center of the Cascade mountains can see an average of 200 inches of snowfall per year, with the highest peaks remaining snow capped throughout the year.
Unlike the western side of the state, which experiences a generally mild climate year round, the eastern side of Washington state can see much hotter summers and much colder winters. Eastern Washington also undergoes a dry season through the summer months, where they can frequently experience 4-8 weeks with only a few scattered showers. This region also experiences windy conditions quite often — with 12 MPH northeasterly winds expected 60-70% of the time during the fall and winter months. Most metal roofing systems will hold up well in the climate challenges the eastern region faces, although certain options could provide you better protection than others.
Roofing in the Different Eastern Washington Regions
It’s important to keep these climatic features in mind when deciding which metal roofing system is best for your eastern Washington home. Unlike the coastal and western side of the state, moisture and precipitation are less of an issue, especially for those directly under the Cascades rain shadow. With fluctuating temperatures from summer to winter and wind being the bigger elements to consider in eastern Washington, metal roofs are a prime choice for homeowners looking for a long-lasting and durable roofing solution.
Eastern Washington state is broken into four main regions including the East-Slope Cascades, Central Basin, Northeastern Mountains, and the Okanogan-Spokane-Palouse Hills.
Roofing for the East Slopes of the Cascades Region
If you reside on the eastern slopes of the Cascades, you fall under the rain shadow effect so moisture and precipitation are not as big of factors. One of the best roofing options for this region is Corrugated or Tuff Rib metal panels because of their durability against the changing seasons and their temperatures. This region sees temperatures below-zero during winter and above 80°F during summer. It’s not uncommon for rapid cooling to occur after sunset due to breezes coming off the mountains. Fluctuating temperatures in this region can cause metal to expand and contract, which may lead to oil canning. You can avoid this by adding striations, a series of ridges and waves, to your metal panels. Metal roofing is the optimal solution for those living in the eastern slopes of the Cascade Mountains.
Roofs for the Central Basin Region
Within the Central Basin Region of eastern Washington, homeowners can experience more wind and drier conditions than others, as this is the lowest and driest section in eastern Washington. Choosing a roofing option with an exposed fastener system also helps keep roofs in windy areas intact. An exposed fastener system will provide a roof with a more rigid connection to the substrate. Homeowners residing in the Central Basin of eastern Washington would benefit greatly from the longevity and strength of metal roofs.
Northeastern Mountains Region Roofing Solutions
Snow is one of the biggest climatic factors for those in the Northeastern Mountain region of Washington state. With increases in elevation and snowfall averaging from 15-80 inches throughout the region, homeowners need a roofing option that can withstand heavy snow loads. It’s important for those with metal roofs to incorporate moisture barriers to protect their roof against snow, as well as designing roofs to prevent ice damming. Both moisture barriers and controlling ice damming can extend the life of a metal roof in the Northeastern Mountain region of Washington.
Best Roof for Okanogan-Spokane-Palouse Hills Region
Comprised of inter-mountain areas and valleys, this region of eastern Washington has a fairly continental climate. However, as elevation increases, so does the amount of rainfall and snowfall, so homeowners may want to consider the heavy snow load roofs. The valley areas of the Okanogan-Spokane-Palouse regions have reported damaging hail storms through the summer months. Choosing a metal roof that can withstand a hailstorm is vital for those residing in this area. For best overall protection, Tuff Rib and Corrugated metal panels, when used in 22, 24, or 26 gauge thickness, can offer strong impact resistance against hail. There is no 100% hail-resistant roofing solution on the market, but both of these options come pretty close.
Overall, homeowners that face heavy snowfall, fluctuating temperatures, and hail storms all have one thing in common: the need for a high-performing roof. Metal roofs are durable, long-lasting, and low maintenance, making them one of the best roofing options for eastern Washington state and the Cascade Mountain region.
