Sheet Metal & Custom Fabrication

Custom Sheet Metal for Performance Driven Building Envelopes

Rainier Building Supply fabricates custom sheet metal components that protect buildings from water intrusion, manage drainage, and support long-term exterior performance. Our work is designed around real job conditions, dimensions that actually fit, details that install cleanly, and materials selected for durability in the field. We support residential, multifamily, and commercial projects with fabrication services that integrate directly with siding, roofing, and waterproofing systems.

What We Fabricate

We produce both standard and fully custom components, with an emphasis on waterproofing, drainage, and architectural integration.

  • Head, sill, and jamb flashing
  • Door pans and window flashing assemblies
  • Transition flashing and WRB integration components
  • Custom waterproofing details built to project conditions
  • Parapet coping
  • Wall caps and trim caps
  • Roof edge and termination flashing
  • Custom wall, roof, and façade vents
  • Metal vent covers and protective hoods
  • Flashing-integrated vent assemblies
  • Airflow flashing components designed to maintain drainage and ventilation paths
  • Custom soffit vent panels
  • Continuous and sectional vented soffit metal
  • Vent trims and terminations coordinated with cladding systems
  • Metal details designed to support balanced airflow and moisture control
  • Custom exterior trims
  • Architectural accents and formed profiles
  • Metal designed to complement modern and traditional façades
  • Custom metal cladding elements
  • Panel trims, reveals, and terminations
  • Integrated details coordinating with siding and rainscreen systems
  • Custom gutters
  • Downspouts and collector boxes
  • Drainage components fabricated for proper water management

Materials We Work With

We fabricate using materials suited for exterior exposure, corrosion resistance, and long-term performance:

  • Prefinished steel
  • Aluminum
  • Stainless steel
  • Galvanized steel
  • TPO- and PVC-wrapped metal components

Material selection is based on application, environment, and compatibility with surrounding systems—not just cost.

Fabrication Capabilities

Our in-house shop is equipped to handle both straightforward production runs and complex, job-specific details.

  • Precision bending and forming
  • Soldered assemblies for watertight performance
  • Custom profiles and non-standard dimensions
  • Small runs to large-scale multifamily production

We fabricate with installation efficiency in mind—clean seams, accurate hems, and consistent tolerances.

Design & Consulting Support

We don’t just fabricate what’s on paper—we help make the details work.

Consulting & Design Services
  • Design-assist for flashing and waterproofing details
  • Custom drawings and job-specific fabrication details
  • Coordination with siding, roofing, and WRB systems
Value Engineering
  • Material and detail optimization
  • Cost-effective alternatives without sacrificing performance
  • Simplifying complex details for practical implementation
Waterproofing Solutions
  • Support for building envelope transitions
  • Metal solutions that integrate with membranes and sealants
  • Practical recommendations based on field experience
Sustainability
  • Durable materials designed for long service life
  • Efficient fabrication practices to reduce waste
  • Long-term performance over short-term fixes

Who We Work With

  • Siding contractors
  • General contractors
  • Builders and developers
  • Design professionals
  • Homeowners 

We regularly support multifamily and commercial projects, as well as residential builds and replacements.

Brands & Products

We carry and source trusted exterior building products from leading manufacturers used across the Pacific region.

Send drawings, photos, or dimensions and our team will help develop a fabrication solution that fits your project.