How To Install Cedar Shake Shingles Siding: Precision Installation Guide

Installing cedar shake shingles siding requires precise moisture management, correct fastener placement, and rigid adherence to exposure rules to ensure a 50-year service life. Achieving a weather-tight envelope involves installing a high-performance weather-resistant barrier with a rainscreen matrix, maintaining a 1/4-inch to 3/8-inch keyway gap between shakes for expansion, and securing each unit with code-compliant stainless steel fasteners. Following Cedar Shake & Shingle Bureau standards prevents cupping, splitting, and water intrusion across all exterior wall assemblies.

Pre-Installation Engineering & Material Preparation

Siding performance relies heavily on proper site preparation and material acclimatization. Western Red Cedar (Thuja plicata) is naturally dimensionally stable due to its low density, but uninstalled shakes must equalize with the local climate’s equilibrium moisture content (EMC) before application. Store cedar shakes flat on pallets elevated at least four inches off the ground in a covered, well-ventilated area for 7 to 10 days prior to installation. Moisture content must read between 10% and 14% using a pin-type moisture meter before fast-tracking the envelope installation.

Building code mandates under International Residential Code (IRC) Section R703.8 require a continuous weather-resistant barrier (WRB) paired with integrated flashing at all wall penetrations, corners, and material transitions. Integrating a 3D entrained air mesh or furring strip rainscreen matrix behind the shakes enables two-way drainage and back-ventilation, preventing moisture-induced tannic acid bleed, wood rot, and paint failure.

Essential Installation Checklist

• Fasteners & Hardware: Type 304 or Type 316 stainless steel ring-shank nails (or ASTM A153 Class C hot-dipped galvanized fasteners), 1-1/2 inch to 2-1/2 inch lengths depending on shake thickness; corrosion-resistant metal Z-flashing; 15-lb or 30-lb asphalt felt paper / commercial drainable housewrap.
• Specialized Tools: Pneumatic siding nailer with adjustable depth-drive, block plane, sliding T-bevel, chalk line, utility knife, speed square, high-grade trim saw, fine-tooth hand saw, pin moisture meter, and a custom-milled story pole.
• Prerequisite Standards: Compliance with Cedar Shake & Shingle Bureau (CSSB) installation specifications, local building department wind-load criteria, and manufacturer-specified WRB integration rules.
• Project Benchmarks: Estimated labor output is 120 to 160 square feet per 8-hour shift for a two-person skilled crew, with total material waste estimated at 10% to 15% for standard wall layouts.

Step-by-Step Exterior Cedar Shake Wall Assembly

Step 1: Substrate Preparation and Rainscreen Matrix Integration

1. Inspect the structural wall sheathing (minimum 7/16-inch OSB or 1/2-inch exterior plywood). Ensure all panels are securely fastened to studs with no vertical deflection or protruding fastener heads.
2. Apply a primary layer of weather-resistant barrier (WRB) starting from the bottom of the wall assembly. Overlap horizontal seams by a minimum of 2 inches and vertical seams by 6 inches.
3. Install a secondary drainage layer or 3D rainscreen mesh directly over the WRB. If using 1x3 cedar or pressure-treated furring strips, fasten them vertically over stud locations at 16-inch centers using corrosion-resistant screws to create a 3/8-inch ventilation air cavity.
4. Affix insect screen mesh along the bottom perimeter of the rainscreen matrix to prevent pest entry while maintaining air intake at the sill base.

Warning: Do not use electro-galvanized or common steel fasteners. Cedar contains high concentrations of natural tannic acids that rapidly corrode non-stainless metals, causing black iron-staining streaks and premature structural failure of the fasteners.

Step 2: Trim, Corner, and Window Flashing Setup

1. Install inside and outside corner boards, allowing a thickness depth that exceeds the thickest butt-end of the cedar shake by at least 1/4 inch to ensure a clean flush reveal.
2. If using a woven corner style instead of solid corner boards, prepare alternating left-and-right lap corners during the course layup process.
3. Apply self-adhered membrane flashing (peel-and-stick) to all window and door rough openings, extending 9 inches beyond edges. Integrate head flashings with a 1/4-inch slope per foot and overlap the upper flap of the WRB over the flashing leg.

Step 3: Laying the Double Starter Course

1. Establish the bottom baseline by snapping a level chalk line around the structure, maintaining a minimum 6-inch clearance from unpaved grade or 2 inches above finished paving/hardscape.
2. Install a continuous metal drip edge along the lower plate, beneath the starter row.
3. Fasten the underlying primary starter course of cedar shingles using full-sized units. Ensure the butt-end extends at least 1 to 1.5 inches below the bottom edge of the wall sheathing or sill plate.
4. Apply the secondary (outer) starter course directly over the first layer. Offset all vertical joints by a minimum of 1-1/2 inches relative to the joints in the underlying course.

Pro-Tip: Pre-sort shakes by width and thickness before securing the starter courses. Reserving wide, straight-grained units for field areas around openings and narrow units for fill work saves significant trimming labor later in the process.

Step 4: Executing Field Runs and Maintaining Joint Stagger

1. Construct a custom wooden story pole marked with course exposures (e.g., 5 inches, 7.5 inches, or 10 inches according to the grade and shake size selected).
2. Snap chalk lines across the rainscreen mesh or sheathing at every course height to guarantee consistent level lines around the building perimeter.
3. Position each shake with a keyway gap (expansion space) between adjacent units: 1/4-inch to 3/8-inch for shakes; 1/8-inch to 1/4-inch for kiln-dried shingles. This prevents buckling during wet, humid conditions.
4. Maintain a minimum vertical joint stagger of 1-1/2 inches between courses across any three adjacent layers. Never align a joint in course three directly over a joint in course one if the distance between them is less than 1-1/2 inches.

Incorrect Alignment (Risk of Leakage): | Course 3 | ------- | | Course 2 | ------- | (Joints align vertically) | Course 1 | ------- | Correct Staggered Layout: | Course 3 | ------- | | Course 2 | ------- | (Joints offset >= 1.5 inches) | Course 1 | ------- |

Step 5: Fastener Mechanics and Placement Rules

1. Use exactly two fasteners per individual shake, regardless of width. Shakes wider than 8 inches require additional internal fasteners spaced 1 inch apart near the center only if specified by localized high-wind codes.
2. Place fasteners 3/4 inch to 1 inch inward from each lateral edge.
3. Drive fasteners 1-1/2 inches to 2 inches above the anticipated exposure line of the subsequent overlying course, ensuring no nail heads remain exposed to weather in the finished field.
4. Drive fasteners flush with the wood surface. Do not countersink or crush the wood fiber cells, as crushed wood creates pockets that trap moisture and cause premature wood rot.

Step 6: Wall Tops, Gables, and Flashing Intersections

1. Measure wall heights continuously to adjust course exposures incrementally (up to 1/4 inch per course) across 5 to 6 runs to align perfectly with window sills, head trim, and soffit lines without awkward narrow courses.
2. For top courses under eaves, cut shakes to width using a fine-tooth hand saw. Fasten with stainless steel face nails driven through countersunk holes, sealed with color-matched exterior polyurethane sealant, or trim with a top shadow moulding.
3. At gable ends, use a sliding T-bevel to match the roof pitch angle, transferring the angle to the cedar shake before trimming with a circular saw or block plane.

Cedar Shake Technical Specifications & Exposure Matrices

Field Diagnostic Troubleshooting & Structural Failures

• Buckling, Tent-ing, or Structural Cupping Across Field Shakes
  
  
  • Root Cause: Insufficient keyway expansion gaps (installed butt-to-butt without space) or high moisture swelling occurring after dry installation.
  • Actionable Fix: Remove damaged shakes using a flat pry bar or specialized shingle ripper tool. Cut replacement units to size, leaving a minimum 5/16-inch expansion clearance on both edges, and re-fasten using flush stainless steel ring-shank nails.
• Accelerated Rot and Substrate Decoupling Near Wall Bases
  
  
  • Root Cause: Direct contact between cedar shakes and masonry or soil, combined with lack of an integrated rainscreen cavity causing liquid water entrapment behind the shakes.
  • Actionable Fix: Snap a cut line 6 inches above unpaved grade or 2 inches above concrete, remove bottom courses with an oscillating multi-tool, install a Z-drip edge flashing with an integrated ventilation mesh, and replace cedar courses with proper ground clearance.
• Dark Iron-Staining Streaks and Fastener Back-Out
  
  
  • Root Cause: Utilization of electro-galvanized or standard steel nails reacting with cedar’s natural tannic acids, or over-driven nail heads penetrating the wood face.
  • Actionable Fix: Extract compromised fasteners, inject exterior-grade polyurethane sealant into nail holes, reinstall Type 316 stainless steel ring-shank nails, and adjust the air pressure regulator on pneumatic nail guns to ensure flush seating.
• Water Intrusion at Exterior Window and Door Caps
  
  
  • Root Cause: Omission of metal head flashing or failure to lap the upper weather-resistant barrier over the vertical leg of the window drip cap.
  • Actionable Fix: Pry off cedar courses directly above window frames, slip self-adhered membrane and Z-flashing under the upper WRB layer, extend flashing 1/4 inch past outer window trim edges with vertical end-dams, and re-lay shakes maintaining a 1/4-inch drainage gap above the metal edge.

Frequently Asked Questions

What is the primary difference between cedar shingles and cedar shakes?

Cedar shingles are smooth, machine-sawn on both sides with precise uniform taper, offering a tailored, formal appearance. Cedar shakes are typically hand-split and resawn, featuring a rough, highly textured face and thicker butt-end, offering a rustic look and increased shadow lines.

Do I need a rainscreen system when installing cedar shake siding?

Yes, installing a rainscreen system—such as a 3D drainage mat or vertical furring strips over a high-performance WRB—is critical. Rainscreens create a continuous drainage cavity that enables equalized air pressure, rapid drying of moisture, and prevents water entrapment that causes premature decay and paint failure.

What size nails should be used for cedar shake siding installation?

Fastener sizes range from 3d (1-1/4 inch) to 6d (2 inch) depending on shake thickness and length. Always select Type 304 or Type 316 stainless steel ring-shank nails that penetrate the wood sheathing or wall studs by a minimum of 3/4 inch to achieve proper wind load holding capacity.

Can cedar shakes be installed over existing wood or vinyl siding?

Installing cedar shakes directly over existing siding is strongly discouraged. Old siding hides underlying rot, prevents proper weather-resistant barrier integration, and impedes keyway expansion space. Strip old siding down to the structural sheathing, inspect substrate integrity, and install a modern WRB/rainscreen system prior to shake installation.

Protect Your Building Envelope with Master-Grade Cedar Application

Mastering the installation of cedar shake siding requires strict attention to structural flashing details, precise fastener alignment, and robust back-ventilation practices. By implementing these engineering specifications, your exterior envelope will deliver maximum curb appeal, energy performance, and structural weather defense for decades.