Meta description: Learn what 18-inch Perfection cedar shingles are, how they differ from other cedar products, where they work best, and what to check before installation.
“18 Perfection cedar shingles” usually refers to 18-inch-long cedar shingles known as Perfections. They are a traditional option for roofs and exterior walls, but the name describes a size category—not a guarantee of a particular wood grade, exposure, or performance. Understanding those differences helps homeowners compare products, plan installation, and avoid ordering the wrong material. Here is what to know about 18-inch Perfection cedar shingles, from common applications to maintenance and code considerations.
What Are 18-Inch Perfection Cedar Shingles?
Perfection cedar shingles are commonly sold in an 18-inch nominal length. They are sawn from cedar and have a tapered shape: the butt, or lower edge, is thicker than the upper portion. Installed in overlapping courses, they create a layered exterior surface that sheds water while showing the shingles’ natural texture.
“Perfection” is a traditional size designation. It should not be read as a grade or a statement that every bundle is identical. Product quality depends on details such as the cedar species, grade, manufacturing standard, and whether the shingles are intended for roofing or sidewall use. Buyers should check the bundle label and product documentation rather than relying on the name alone.
Western red cedar is a familiar choice for shingles because it is relatively lightweight and naturally resistant to decay. Other cedar species may also be available. Color, grain, durability, and local availability vary, so the species should be confirmed before purchase.
Common Sizes and How Perfections Compare
Cedar shingles are often grouped by nominal length. Perfections are typically 18 inches; shorter and longer options may be sold under other traditional names, including Fivex and Royal. Exact product descriptions and customary exposure recommendations can vary by manufacturer and intended application.
| Common category | Typical nominal length | General planning note |
|---|---|---|
| Fivex | 16 inches | Shorter shingle; verify the specified course exposure. |
| Perfection | 18 inches | A widely used middle length for roofs and sidewalls. |
| Royal | 24 inches | Longer shingle; often used where a larger scale is desired. |
These names describe customary length categories, not interchangeable installation instructions. The correct exposure—the portion of each shingle left visible after the next course is laid—depends on the product, roof pitch, application, and manufacturer’s directions. For example, guidance for a particular 18-inch roofing shingle cannot automatically be applied to an 18-inch sidewall shingle.
Roofing Versus Sidewall Applications
Roof applications
On a roof, the overlapping courses form a water-shedding surface. The shingle length, exposure, roof slope, underlayment, flashing, and ventilation all affect how the assembly performs. Roofs typically require more conservative exposure than walls because they are directly exposed to rain, snow, and flowing water.
Before ordering for a roof, confirm that the selected shingles are approved or specified for roofing. Check the recommended exposure and minimum roof slope in the manufacturer’s instructions. Local building codes and project conditions may impose additional requirements. A roof covering should not be designed from nominal length alone.
Sidewall applications
Perfection shingles are also used on exterior walls, where they create a textured, traditional finish. Wall exposure may differ from roof exposure, and details around windows, doors, corners, and the foundation need careful planning. A properly installed water-resistive barrier and appropriate flashing remain important behind cedar siding.
Wall shingles are not simply roof shingles installed vertically by default. Product specifications may distinguish between roofing and siding use, and the wall assembly must be designed to manage water. The project’s plans and manufacturer guidance should identify the correct materials and details.
Grades, Appearance, and Product Labels
Cedar shingle grades describe qualities such as the amount of clear wood, knots, and other characteristics. Grade names and definitions should be verified against the applicable standard and supplier documentation. A higher grade generally has more restrictive appearance requirements, but the specific description matters more than a sales shorthand.
When comparing bundles, ask for the following information:
- Species: Confirm whether the product is Western red cedar or another cedar species.
- Grade and standard: Request the grade designation and the standard under which the shingles were manufactured or inspected.
- Intended use: Verify whether the shingles are for roofing, sidewalls, or both.
- Dimensions and exposure: Check actual nominal length, thickness, and recommended exposure.
- Treatment: Determine whether the product is untreated, preservative-treated, fire-retardant-treated, or factory-finished.
- Coverage: Ask how many square feet a bundle covers at the specified exposure.
Appearance also varies naturally. Cedar shingles can show differences in color and grain within a bundle and between bundles. If a uniform appearance is important, discuss sorting, blending, and finishing with the installer or supplier before work begins.
Estimating Coverage and Material Needs
Coverage is not determined by shingle length alone. It depends on the manufacturer’s stated coverage per bundle at a particular exposure, the number of courses, the roof or wall layout, and the amount of cutting required. A bundle’s listed coverage should be treated as an estimate for its specified installation conditions, not a universal figure.
To estimate an order, measure the net area to be covered, subtract large openings where appropriate, and divide by the product’s stated coverage per bundle. Add a reasonable allowance for trimming, breakage, layout, and future repairs. Complex roofs, dormers, valleys, and many openings can increase waste. The supplier or contractor can check the calculation against the project drawings.
It is often useful to keep a small quantity of matching shingles after installation. Cedar naturally weathers, so replacement material from a later production run may not match the existing surface exactly. Store extra shingles dry and in accordance with the manufacturer’s recommendations.
Installation Details That Affect Performance
Good installation depends on more than attaching shingles in evenly spaced rows. The installer must follow the product’s specified exposure, joint spacing, fastener placement, and fastening schedule. Shingles should be arranged so joints in one course do not line up with joints in the adjacent courses, which helps prevent direct paths for water.
Fastener type and placement matter. Corrosion-resistant nails are commonly specified for cedar, but the appropriate material, size, and number depend on the product and exposure conditions. Fasteners placed incorrectly can split the shingle or fail to hold it securely. The manufacturer’s instructions and applicable building code should control.
Roof assemblies also need properly detailed valleys, ridges, eaves, penetrations, and flashing transitions. For walls, installers need to coordinate shingles with housewrap or another water-resistive barrier, flashing, trim, and openings. A qualified contractor should be familiar with cedar installation and local code requirements.
Ventilation and moisture management are important in both applications. Trapped moisture can contribute to deterioration, while excessive heat or poor ventilation can affect the roof assembly. The appropriate underlayment, ventilation strategy, and water-control details depend on the building and local conditions.
Finishes, Weathering, and Maintenance
Unfinished cedar typically changes color as it is exposed to sunlight and weather. The resulting appearance may vary with climate, shade, moisture, and surrounding conditions. A finish can alter the initial color and influence how the surface weathers, but it does not eliminate the need for sound installation and periodic inspection.
Finish choices include products intended to preserve color, add a tint, or provide other specified protection. Not every coating is suitable for cedar shingles, and some finishes require more frequent maintenance than others. Use a product approved for the application and follow preparation and reapplication instructions. Before coating a large area, test the finish on sample shingles.
Inspections can help identify displaced or damaged shingles, failing flashing, debris buildup, and signs of moisture problems. Roof inspections should be performed safely, often by a professional. Promptly addressing localized damage can reduce the chance that water reaches the layers beneath the shingles.
Fire, Building Codes, and Local Requirements
Wood shingles are combustible, and fire performance depends on the specific product and assembly. Some products are factory treated for fire resistance, but treatment does not mean that every installation is allowed in every location. Requirements can vary by jurisdiction, building type, roof assembly, and wildfire exposure.
Before buying 18-inch Perfection cedar shingles, check with the local building department, project designer, or qualified contractor. Ask whether wood shingles are permitted and whether the project requires a listed or tested assembly, a particular fire classification, or specific installation details. In areas with elevated wildfire risk, local rules may be especially restrictive.
For general technical information on cedar shingle grades and installation, consult the Cedar Shake & Shingle Bureau and the product manufacturer. Local codes and approved project documents take precedence over general online guidance.
Cost Factors and Choosing a Supplier
The price of 18-inch Perfection cedar shingles varies with species, grade, treatment, finish, region, availability, and order size. Total project cost also includes underlayment or other assembly materials, flashing, fasteners, labor, access equipment, waste, and disposal. A low bundle price may not represent the lowest installed cost if the product has different coverage or requires more preparation.
For a useful comparison, request written quotes that specify the same shingle length, species, grade, intended application, exposure, treatment, and coverage basis. Confirm freight charges, lead times, storage expectations, and the supplier’s return policy. Ask the installer to identify any code-related or assembly requirements in the proposal.
Questions to Ask Before Ordering
- Are these 18-inch Perfection shingles intended for roofing, sidewalls, or both?
- What species and grade are supplied, and how are those claims documented?
- What exposure and installation details apply to this exact product?
- How many square feet does each bundle cover at that exposure?
- Are treatment or finishing options available, and are they appropriate for the project?
- Does the local jurisdiction permit this material and assembly?
- What materials are required for flashing, underlayment, ventilation, and fastening?
In practical terms, 18-inch Perfection cedar shingles are a length category rather than a complete product specification. The right choice depends on the intended use, grade, species, exposure, installation instructions, and local code. Confirming those details before purchase helps ensure that the shingles suit the building and that coverage and cost estimates are based on the actual product.