How Rainscreen Cedar Breathers Solve Moisture Issues in Western Washington Homes

Western Washington’s climate presents a unique challenge for home exteriors. Frequent rain, persistent humidity and mild temperatures create an environment where moisture intrusion into wall assemblies is a constant threat. For homeowners in places like Sammamish, this means traditional siding and cladding materials—especially wood or cedar—are at risk of warping, rot and premature failure.

Enter the solution: the rainscreen cedar breather system. By creating a ventilated gap behind the siding and enabling proper drainage and airflow, a rainscreen cedar breather extends the life of your exterior and protects your home from moisture‑related damage. In this blog, you’ll learn what the system is, why it matters in Western Washington, how to select the right product, how installation should be handled, and mistakes to avoid.

What is a Rainscreen Cedar Breather?

A rainscreen cedar breather system combines two key principles: a rainscreen (an air gap or drainage space behind the siding) and a breather layer (an underlayment or mat that promotes airflow and drainage). In essence, the siding is mounted over a ventilated cavity which allows moisture that penetrates or condenses behind the siding to escape, rather than being trapped against the weather‑resistive barrier or sheathing.

The term “rainscreen” refers to the drainage/vent space behind cladding whereby water that penetrates the outer layer is allowed to drain out and air is permitted to flow, accelerating drying.The “cedar breather” component, as exemplified by products like Cedar Breather, provides a three‐dimensional matrix under the siding that establishes this required space and ensures continuous airflow and drying.

In practical terms, for your home in Sammamish, it means when cedar siding is applied, you’re not just fastening wood to sheathing and hoping for the best—you’re building in a performance layer that manages moisture behind the siding.

Why It Matters in Western Washington & Sammamish

The Western Washington climate is characterized by frequent precipitation (rain, snow, mist), elevated humidity, and moderate temperatures year‑round. These conditions heighten the risk of moisture penetration behind siding, condensation, and slow drying of exterior walls. A typical siding installation without a ventilated gap can leave trapped moisture behind the cladding, leading to rot, mold, degradation of sheathing, fasteners, and the siding itself.

In areas like Sammamish, where premium homes often utilize cedar or wood cladding for aesthetic and market value reasons, ignoring moisture management isn’t just a maintenance detail—it impacts durability and long‑term value. A named rainscreen cedar breather approach offers insurance: it’s an investment that addresses the particular weather challenge of this region.

Specific Moisture Risks to Cedar and Wood Exterior Systems

Cedar siding or shakes are popular for their appearance, natural character and durability—but only when installed and maintained correctly. When cedar is applied directly to sheathing or house‑wrap without a ventilated gap, several risks emerge:

• Warping and cupping: Excess moisture behind cedar causes boards to distort. A breather system provides a space for air to circulate and the back of the siding to dry.
• Rot and mold: If moisture becomes trapped between siding and sheathing, decay or microbial growth can start, compromising structural integrity.
• Degradation of fasteners or sheathing: Moisture‐laden sheathing expands/contracts, screws or nails may lose holding power, siding may loosen.
• Reduced lifespan: Instead of cedar siding lasting decades, you face more frequent refurbishing or replacement.

By using a rainscreen cedar breather system, you effectively provide a channel for ventilation and a capillary break behind the siding. Every inch of wood cladding becomes more resilient and better able to dry after rainfall or humidity fluctuations.

Key Benefits for Homeowners

Here’s what a homeowner in Sammamish stands to gain by installing a rainscreen cedar breather system:

• Extended lifespan of siding and cladding: With better drying and ventilation, the siding lasts longer, reducing lifecycle costs.
• Reduced maintenance and repair costs: Less chance of rot or moisture damage means fewer callbacks, fewer repainting issues or replacements.
• Better indoor wall cavity health: Minimizing moisture intrusion means less mold risk, fewer performance issues in the wall assembly.
• Potential energy/thermal benefits: While not the primary intent, an air gap reduces moisture load and may help with condensation control. Some product descriptions highlight thermal break and noise reduction features.
• Improved resale & curb appeal: Homes in Western Washington that show proper exterior detailing stand out in value.

How to Choose and Specify a Good Rainscreen Cedar Breather System

When reviewing options for your home, focus on the following product and system criteria:

• Design of the air gap / void space: Products should clearly specify the thickness/void that provides drainage and air flow. According to manufacturer guidance, the air space should be at least ~3/16″ to break capillary bridging.
• Compatibility with your cladding (cedar/wood) and fasteners: The product you choose should be intended specifically for cedar siding or shakes, or at least rated for wood cladding.
• Fire resistance and durability: In Western Washington you want materials that handle moisture, UV exposure and local building code requirements. For example, Cedar Breather has a Class A fire rating.
• Ease of installation and contractor familiarity: Choose a system that your contractor has used before or that has strong documentation and guidance (installation guides, flashing details, etc).
• Warranty and longevity assurances: Since this is an investment in durability, ensure the product/vendor supports long‐term performance.
• Detailing and drainage path: Ventilation at top and bottom of the air gap, proper flashing, and drainage must be part of the assembly. Without these details the benefit is compromised.

From a budgeting/ROI standpoint, while there is additional upfront cost compared to a non‐rainscreen installation, the reduction in future maintenance, risk mitigation of moisture damage, and extended siding lifespan make it a smart investment.

Installation Tips & Best Practices for Sammamish Area Homes

To ensure the system performs as intended, follow these best practices:

1. Work with a contractor experienced in rainscreen systems—They should understand drainage planes, air flow design, flashing and local climate implications.
2. Proper flashing, ventilation openings at top & bottom—Air intake at the base of the wall and exhaust at the top help drive convective drying. Without both, moisture may become trapped.
3. Mount siding over the breather/underlayment per manufacturer’s instructions—Avoid compressing the air gap, ensure the cladding does not block airflow.
4. Choose materials rated for local exposure—Westside Washington homes face rain, wind and temperature fluctuations—so UV resistant, moisture resistant products are important.
5. Inspect after installation and maintain the ventilation channel—Clean debris from vent openings, check for insect intrusion, ensure the cavity remains clear.
6. Mind timing of installation—While you can install during many months, it’s better to avoid heavy rain periods or ensure temporary protection during the job.

Common Mistakes to Avoid:

• Installing siding directly over housewrap / sheathing without a ventilated gap.
• Skipping or poorly executing flashing around windows, doors, penetrations—these become moisture traps.
• Compressing or blocking the breather layer during siding installation (nails too long, siding tight).
• Using products not rated for wood siding or ignoring manufacturer specs.

‍

For homeowners in Western Washington, the investment in a rainscreen cedar breather system is a strategic decision. With the region’s moist climate, good intentions alone are not enough; you need a system that actively manages moisture, enables drying and protects your home’s exterior assembly over decades.

By choosing the right product, insisting on proper installation, and maintaining the ventilation path, you significantly reduce risk, improve your siding’s lifespan, lower maintenance costs and bolster your home’s value. If you’re planning an exterior upgrade or installing cedar siding, contact us to day for a complimentary consultation.

FAQs

Q1. What exactly is a “rainscreen” and how is it different from regular siding installation?
A: A rainscreen adds a ventilated air space behind the siding that allows drainage and drying of any moisture that penetrates the siding, whereas a regular installation often has siding mounted directly over housewrap or sheathing, with little ability for air flow or drying.

Q2. Will a rainscreen cedar breather system work with my existing cedar siding, or only new installations?
A: It depends on condition and how the siding is mounted. Often it’s best incorporated at siding replacement or major reroof/cladding jobs. Contact us for a complimentary evaluation to see what's feasble.

Q3. Do I still need to maintain my cedar siding even with a rainscreen system?
A: Yes. While the system reduces risk, you still need proper flashing, clean vent openings, regular inspections, finish re‑coats, and ensure no damage or blockage in the ventilation gap.

Q4. How do I know if I have moisture problems in my wall assembly and whether a rainscreen system would help?
A: Signs include warped or cupped siding, recurring rot or repairs behind cladding, blistering paint, mold or mildew in wall cavities, or visible staining on siding or sheathing. A professional inspection can reveal whether a rainscreen solution is warranted.

‍