CSSB Trade Show & AGM 2026
October
14-15, 2026
Chicago, IL
Is Cedar Siding a Good Choice for Wet Climates?
Press Release |
October 16, 2026
Few questions come up more consistently among architects and contractors working in high-rainfall regions than whether cedar siding belongs on a wet-climate building. At the Cedar Shake & Shingle Bureau, we’ve watched cedar perform across some of North America’s most demanding coastal and Pacific Northwest environments. The answer isn’t a simple yes or no. It depends on species selection, grade, installation practice, and ongoing maintenance. Get those variables right, and cedar is among the most resilient exterior cladding options available. Get them wrong, and moisture becomes an adversary rather than a manageable factor.
Cedar’s Natural Resistance to Moisture
Western red cedar’s durability in wet climates is biological. The species contains naturally occurring thujaplicins, a class of tropolone compounds with proven antifungal properties. Combined with cedar’s low density and stable cellular structure, these give it an inherent resistance to decay that most softwood species simply don’t possess.
Several properties support performance in wet conditions. Cedar’s low shrink-swell ratio means it absorbs and releases moisture with minimal dimensional movement, reducing the risk of splitting, cupping, and joint failure. Its natural oils and phenolic compounds actively resist fungal decay and insect activity without chemical treatment. Across seasonal moisture cycles, that cellular stability translates to consistent performance where prolonged wet seasons would compromise lesser materials.
Higher-grade cedar siding carries more of these extractives and performs more predictably over time. In wet climates, grade selection isn’t aesthetic preference; it’s a performance specification.
Find out how long a cedar roof lasts.
Where Installation Practice Determines Outcomes
No species, however naturally resistant, can compensate for poor installation. In wet climates, installation details are the difference between a fifty-year exterior and a fifteen-year problem.
Ventilation and Back-Priming
Cedar siding needs to breathe. A ventilated rainscreen gap behind the cladding allows moisture that penetrates the face of the boards to drain and dry rather than accumulate against the substrate. This assembly reduces bulk water intrusion and prevents the saturation cycles that accelerate decay even in naturally durable species.
Back-priming (applying a coat of primer or water-repellent to the back face and edges of each board before installation) is standard practice in wet climates and a significant factor in long-term performance. Unsealed end grain is the primary moisture entry point in any wood siding application.
Clearances, Drainage, and Fastening
Maintain a minimum clearance between the bottom course and finished grade, roof surfaces, and horizontal trim elements. Ensure positive drainage away from the building at all horizontal surfaces. Cut all field joints square and seal end grain before installation. Use corrosion-resistant fasteners, either hot-dipped galvanized or stainless steel, to prevent staining and fastener failure in high-moisture environments.
Finish Coatings
Cedar accepts both solid and semi-transparent finishes. In wet climates, penetrating finishes that allow moisture vapour transmission generally outperform film-forming coatings, which can trap water beneath the surface. The finish schedule and reapplication cycle should be established at the time of installation and communicated clearly to the building owner.
Maintenance Expectations in High-Rainfall Regions
Cedar siding in wet climates is not a set-and-forget application. Professionals should communicate realistic maintenance expectations to clients upfront.
Inspect annually for areas where the finish has worn, with particular attention to sun-exposed south and west elevations and roof eaves where water concentrates. Recoat cycles vary by product type, exposure, and climate zone, but high-rainfall regions consistently demand more frequent attention than arid ones. Keep surfaces free of leaves, moss, and organic debris, all of which trap moisture against the cladding when left to accumulate. Cedar’s extractives resist fungal growth, but surface mildew can still develop on the finish layer. Address it promptly with appropriate cleaning before recoating.
Learn more about maintaining cedar sidewalls.
When Cedar Remains the Right Material
The Pacific Northwest, one of the rainiest inhabited regions on the continent, has been cedar country for generations. Historic structures clad in cedar throughout coastal British Columbia, Washington, and Oregon continue to stand as evidence that the material, properly installed and maintained, belongs in wet climates. Cedar’s thermal properties, workability, and visual character make it difficult to replace on purely practical grounds.
That said, cedar is not appropriate for every wet-climate application. Below-grade or near-grade contact, consistently submerged conditions, or applications where maintenance will not be performed on a reasonable schedule are scenarios where alternatives merit serious consideration.
Informed Decisions Start with the Right Resources
Cedar siding is a sound choice for wet climates when specified, installed, and maintained to professional standards. At the Cedar Shake & Shingle Bureau, we have supported the trade community with technical documentation, grading standards, and certification resources for over a century. If you’re working through material selection, installation specifications, or maintenance protocols for a project in a high-rainfall environment, reach out through our contact form.
Few questions come up more consistently among architects and contractors working in high-rainfall regions than whether cedar siding belongs on a wet-climate building. At the Cedar Shake & Shingle Bureau, we’ve watched cedar perform across some of North America’s most demanding coastal and Pacific Northwest environments. The answer isn’t a simple yes or no. It depends on species selection, grade, installation practice, and ongoing maintenance. Get those variables right, and cedar is among the most resilient exterior cladding options available. Get them wrong, and moisture becomes an adversary rather than a manageable factor.
Cedar’s Natural Resistance to Moisture
Western red cedar’s durability in wet climates is biological. The species contains naturally occurring thujaplicins, a class of tropolone compounds with proven antifungal properties. Combined with cedar’s low density and stable cellular structure, these give it an inherent resistance to decay that most softwood species simply don’t possess.
Several properties support performance in wet conditions. Cedar’s low shrink-swell ratio means it absorbs and releases moisture with minimal dimensional movement, reducing the risk of splitting, cupping, and joint failure. Its natural oils and phenolic compounds actively resist fungal decay and insect activity without chemical treatment. Across seasonal moisture cycles, that cellular stability translates to consistent performance where prolonged wet seasons would compromise lesser materials.
Higher-grade cedar siding carries more of these extractives and performs more predictably over time. In wet climates, grade selection isn’t aesthetic preference; it’s a performance specification.
Find out how long a cedar roof lasts.
Where Installation Practice Determines Outcomes
No species, however naturally resistant, can compensate for poor installation. In wet climates, installation details are the difference between a fifty-year exterior and a fifteen-year problem.
Ventilation and Back-Priming
Cedar siding needs to breathe. A ventilated rainscreen gap behind the cladding allows moisture that penetrates the face of the boards to drain and dry rather than accumulate against the substrate. This assembly reduces bulk water intrusion and prevents the saturation cycles that accelerate decay even in naturally durable species.
Back-priming (applying a coat of primer or water-repellent to the back face and edges of each board before installation) is standard practice in wet climates and a significant factor in long-term performance. Unsealed end grain is the primary moisture entry point in any wood siding application.
Clearances, Drainage, and Fastening
Maintain a minimum clearance between the bottom course and finished grade, roof surfaces, and horizontal trim elements. Ensure positive drainage away from the building at all horizontal surfaces. Cut all field joints square and seal end grain before installation. Use corrosion-resistant fasteners, either hot-dipped galvanized or stainless steel, to prevent staining and fastener failure in high-moisture environments.
Finish Coatings
Cedar accepts both solid and semi-transparent finishes. In wet climates, penetrating finishes that allow moisture vapour transmission generally outperform film-forming coatings, which can trap water beneath the surface. The finish schedule and reapplication cycle should be established at the time of installation and communicated clearly to the building owner.
Maintenance Expectations in High-Rainfall Regions
Cedar siding in wet climates is not a set-and-forget application. Professionals should communicate realistic maintenance expectations to clients upfront.
Inspect annually for areas where the finish has worn, with particular attention to sun-exposed south and west elevations and roof eaves where water concentrates. Recoat cycles vary by product type, exposure, and climate zone, but high-rainfall regions consistently demand more frequent attention than arid ones. Keep surfaces free of leaves, moss, and organic debris, all of which trap moisture against the cladding when left to accumulate. Cedar’s extractives resist fungal growth, but surface mildew can still develop on the finish layer. Address it promptly with appropriate cleaning before recoating.
Learn more about maintaining cedar sidewalls.
When Cedar Remains the Right Material
The Pacific Northwest, one of the rainiest inhabited regions on the continent, has been cedar country for generations. Historic structures clad in cedar throughout coastal British Columbia, Washington, and Oregon continue to stand as evidence that the material, properly installed and maintained, belongs in wet climates. Cedar’s thermal properties, workability, and visual character make it difficult to replace on purely practical grounds.
That said, cedar is not appropriate for every wet-climate application. Below-grade or near-grade contact, consistently submerged conditions, or applications where maintenance will not be performed on a reasonable schedule are scenarios where alternatives merit serious consideration.
Informed Decisions Start with the Right Resources
Cedar siding is a sound choice for wet climates when specified, installed, and maintained to professional standards. At the Cedar Shake & Shingle Bureau, we have supported the trade community with technical documentation, grading standards, and certification resources for over a century. If you’re working through material selection, installation specifications, or maintenance protocols for a project in a high-rainfall environment, reach out through our contact form.
