Building Better Exterior Systems for BC Weather

In the Fraser Valley, heavy rainfall and persistent moisture challenge the durability of building exteriors year after year. Many assume that metal siding alone can protect a structure, but without a proper rainscreen system, moisture can become trapped behind the exterior finishes. This trapped moisture leads to rot, mold, and premature failure of materials, reducing the lifespan of the building envelope.

West Royal Contracting builds exterior systems designed specifically for British Columbia’s wet climate. By combining metal siding, metal roofing, and other cladding materials with effective rainscreen systems, ventilation, and quality waterproofing, buildings can withstand the region’s harsh weather for decades.

!Eye-level view of metal siding installation with rainscreen system on a commercial building in Fraser Valley

integrated rainscreen systems for metal siding

Why Metal Siding Needs More Than Just a Surface Layer

Metal siding offers excellent durability, low maintenance, and long-term protection. For clients looking to further improve building performance in the Fraser Valley climate, West Royal Contracting can also offer rainscreen systems designed to help exterior walls breathe and manage moisture more effectively.

Although not always required, rainscreen systems can help improve the lifespan of your building while reducing future maintenance concerns.

Combined with concealed fastening systems, ventilation details, and proper waterproofing practices, these systems are designed for long-lasting performance in British Columbia weather conditions.

Trapped moisture causes several problems:

• Wood framing and sheathing can rot

• Mold and mildew growth increases health risks

• Fasteners may corrode or loosen, leading to siding failure

• Exterior finishes deteriorate prematurely, requiring costly repairs

  
  

A rainscreen system creates a gap between the siding and the building’s sheathing, allowing air to circulate and water to drain away. This ventilation helps the building “breathe,” reducing moisture buildup and extending the life of the siding and structure.

How Horizontal Rainscreen Systems Improve Building Performance

West Royal Contracting recommends horizontal rainscreen systems when installing metal siding, stone features, or other cladding. This system includes:

• A drainage plane behind the siding to channel water away

• Ventilation openings at the top and bottom to promote airflow

• A durable, weather-resistant barrier on the sheathing

• Proper flashing and waterproofing details to prevent leaks

  
  

This setup allows any moisture that penetrates the siding to drain out quickly and air to flow freely behind the cladding. The result is a dry, stable wall assembly that resists rot, mold, and fastener failure.

Additional Best Practices for Exterior Systems

To further protect buildings in wet climates, West Royal Contracting also recommends:

• Using concealed fastening systems when possible to reduce water penetration and improve aesthetics

• Installing bug screens at ventilation openings to prevent insect intrusion

• Selecting durable, low-maintenance exterior materials suited for BC weather

• Ensuring proper ventilation behind all cladding systems to maintain airflow

• Applying high-quality waterproofing membranes and flashing details around windows, doors, and joints

  
  

These measures work together to create a resilient exterior system that requires less maintenance and lasts longer.

Examples of Effective Exterior Systems in BC

West Royal Contracting has applied these principles across various projects, including custom shops, agricultural buildings, commercial properties, and residential renovations. For example:

• A custom agricultural shop in the Fraser Valley used metal siding with a horizontal rainscreen and concealed fasteners. This combination prevented moisture buildup despite heavy seasonal rains, reducing maintenance costs.

• A commercial building renovation incorporated stone cladding with a rainscreen system and bug screens at ventilation points. The building envelope remained dry and mold-free after several wet winters.

• Residential exterior upgrades included metal roofing paired with proper ventilation and flashing details, extending the roof’s lifespan and preventing leaks.

  
  

These examples show how investing in well-designed exterior systems pays off in durability and peace of mind.

!High angle view of a commercial building with metal roofing and rainscreen cladding system

Building for the Long Term in BC’s Climate

The Fraser Valley’s wet climate demands building systems that go beyond surface protection. Metal siding and metal roofing are excellent choices, but they must be paired with rainscreen systems, ventilation, and quality waterproofing to perform well over time.

West Royal Contracting focuses on general contracting and shop builder projects that prioritize these durable building practices. Their approach avoids shortcuts that lead to early failure and costly repairs. Instead, they build exterior systems designed to last through many seasons of rain, wind, and moisture.

If you want a building that stands strong in BC’s challenging weather, consider:

• Installing horizontal rainscreen systems behind metal siding or cladding

• Using concealed fasteners and bug screens for added protection

• Choosing durable, low-maintenance materials suited for wet climates

• Ensuring proper ventilation and waterproofing details throughout the exterior

  
  

Contact West Royal Contracting to learn more about metal siding systems, rainscreen construction, and long-lasting exterior solutions built to perform in the Fraser Valley and beyond.