Cedar planks are flat cedar boards sold in different species, grades, dimensions, moisture conditions, and profiles for building, woodworking, or cooking. The word “plank” doesn’t confirm structural strength, outdoor durability, treatment status, or food safety, so buyers must check the full specification.
Table of Contents
What Are Cedar Planks?
Cedar lumber includes rough or surfaced boards used for fences, decks, siding, furniture, closets, saunas, and garden structures. Thin culinary boards may carry the same cedar-plank label, yet they belong to a separate product category with stricter contamination and treatment requirements.
Boards Versus Planks
Retailers often use boards and planks interchangeably. Neither term establishes a standard thickness, species, grade, or use, so compare the listed actual dimensions and product description rather than relying on the name.
Construction versus cooking planks: A construction board may have preservatives, finishes, adhesive residue, metal dust, or workshop contamination. A cooking plank must be untreated, uncoated, clean, and represented by its supplier as suitable for culinary use.
Lumber Profiles and Surfacing
Rough-sawn cedar retains saw marks and may be close to its nominal dimensions. S2S lumber has two surfaced faces, while S4S has four smooth faces; this S4S lumber guide explains how milling changes dimensions and edge quality.
Profile selection affects coverage and water movement. Tongue-and-groove suits ceilings and protected walls, bevel boards shed rain on siding, shiplap overlaps at the edges, and square-edge stock works for shelving, trim, fences, and furniture.
Structural and treatment labels: Appearance-grade cedar isn’t automatically approved for joists, beams, rafters, or posts. Load-bearing work needs the required grade stamp and code-compliant span, while soil contact calls for material approved for that exposure rather than an assumption about natural decay resistance.
Cedar Species and Properties
The cedar name covers several distinct woods with different colors, scents, hardness, board sizes, and durability. Ask for the botanical or recognized commercial species when performance matters.
Western Red Cedar Lumber
Western Red Cedar, or Thuja plicata, is a lightweight Pacific Northwest species used for siding, decking, fencing, trim, garden structures, and culinary planks. Despite its name, it belongs to the cypress family rather than the true cedar genus Cedrus.
Freshly cut western red cedar lumber releases a dry, resinous scent, while heartwood can range from straw-brown to pinkish red with dark streaks. Its low weight makes a long board easy to carry, but the soft face picks up dents from dropped tools and sharp furniture feet.
Average reference figures include about 23 pounds per cubic foot in dried weight and a Janka hardness near 350 pound-force. The USDA Wood Handbook explains why moisture, growth conditions, grain, and test methods cause real boards to vary from published averages.
Eastern redcedar: Juniperus virginiana is denser and harder, with reddish-purple heartwood, pale sapwood, and a sharp pencil-box aroma. It suits closet lining, chests, drawers, and small projects; see the Eastern redcedar guide for identification details.
Northern white cedar: Thuja occidentalis is pale, light, and naturally decay resistant. Regional mills in the northeastern and north-central United States and Canada commonly supply it for fencing, shingles, rustic structures, canoes, and outdoor furniture.
Generic and Imported Cedar
A label reading only “cedar” can describe unrelated imported woods, including Spanish cedar and other aromatic species. Verify species, origin, grade, treatment, moisture condition, and intended use before comparing the board with western cedar lumber.
Heartwood versus sapwood: Darker heartwood contains most of the extractives associated with natural decay resistance. Pale sapwood absorbs moisture readily and can decay much sooner, which is why a board’s heartwood percentage may matter more than a broad species claim.
Density, hardness, and stability: Western Red Cedar’s low density eases cutting, drilling, and overhead installation. Its low shrinkage supports stable siding and trim, yet wide flat-grain boards can still cup when one face stays wetter than the other.
Certified sourcing: FSC, PEFC, and SFI labels can document forest management or chain of custody, but the claim must apply to the product being purchased. The FSC label guide explains the differences among its product marks.
Choosing Cedar Planks by Use
Choose cedar planks by exposure and function, then select species, grade, thickness, moisture condition, finish, and fasteners. A clear sauna board, a knotty fence picket, and a structural post solve different problems.
Application Decision Table
| Use | Practical specification | Main risk |
|---|---|---|
| Fence | Knotty heartwood cedar; dry or partly seasoned; stainless or hot-dipped galvanized fasteners | Wet end grain and soil contact |
| Deck | Decking grade, commonly 5/4 or thicker; penetrating exterior stain | Dents, trapped water, slippery growth |
| Siding | Profiled Western Red Cedar; dry; coated on schedule | Poor flashing and tannin bleed |
| Closet | Aromatic Eastern redcedar; dry appearance grade | Expecting scent to replace pest control |
| Raised bed | Thick untreated heartwood boards | Sapwood decay and wet soil |
| Sauna | Dry, smooth, low-resin clear or sound-knot boards | Hot metal fasteners and splinters |
| Furniture | Dry, acclimated clear or selected knotty stock | Denting and joint movement |
| Grilling | Untreated culinary plank | Chemical contamination or fire |
Practical Notes From Real-World Use: Sight down every board before purchase. A straight edge can still hide twist; place one end on a flat cart and press opposite corners—rocking signals twist that fasteners may not pull flat without splitting the soft fibers.
Fences, Decks, and Siding
Fences benefit from cedar’s low weight and easy cutting, but posts face harsher moisture than pickets. Keep board ends above soil, cap upward-facing grain where practical, and use the wood fence guide to compare post and infill options.
Decks and siding need drainage more than thick coatings. Flash wall openings, maintain prescribed clearances, ventilate cladding cavities where the assembly calls for them, and prevent leaves from packing between deck boards and joists.
Interiors, closets, and saunas: Acclimate boards before fitting tight joints. Cedar feels warm and dry under the palm compared with tile, yet rough grain and raised fibers can catch bare skin, so sand seating and backrest surfaces with the grain.
Raised beds and gardens: Use untreated, thick heartwood and detail the corners so water can drain. An impermeable liner pressed tightly against the wood can hold condensation and damp soil against the board, shortening service life instead of extending it.
Structural and furniture uses: Structural components need an applicable grade, verified spans, and approved connectors. Furniture stock should reach the room’s service moisture before final milling; otherwise, wide doors and tabletops may shrink after assembly.
Cedar versus alternatives: Pressure-treated pine often costs less and comes in ground-contact grades, Douglas fir carries loads better, redwood and cypress offer comparable outdoor options in some regions, and composites resist splinters but retain heat and move with temperature.
Cedar Sizes, Grades, and Moisture
Cedar sizes are sold using nominal labels, but calculations must use actual width, thickness, and exposed face. Grade and moisture influence appearance, movement, machining, and cost just as much as size.
Nominal Versus Actual Sizes
| Nominal size | Common surfaced actual size |
|---|---|
| 1 × 4 | 3/4 × 3 1/2 inches |
| 1 × 6 | 3/4 × 5 1/2 inches |
| 1 × 8 | 3/4 × 7 1/4 inches |
| 1 × 10 | 3/4 × 9 1/4 inches |
| 2 × 4 | 1 1/2 × 3 1/2 inches |
| 2 × 6 | 1 1/2 × 5 1/2 inches |
| 5/4 × 6 decking | Often about 1 × 5 1/2 inches |
Actual dimensions vary by mill, region, profile, and moisture condition. Measure delivered stock before laying out joinery or coverage; the lumber dimensions guide covers common sizing conventions.
Common lengths and profiles: Retail lengths often run from 6 to 16 feet. Long clear boards cost more and may need dedicated freight, while tongue-and-groove, bevel, shiplap, channel, and grooved decking profiles have less exposed coverage than their full width.
Clear and Knotty Grades
Clear cedar has few visible knots on its graded face and suits trim, millwork, doors, furniture, sauna interiors, and refined siding. Knotty cedar costs less and works well for fences, pergolas, rustic walls, and garden structures.
Select Tight Knot, often shortened to STK, describes appearance stock with sound knots under the applicable grading rules. Tight knots can still shrink differently from nearby fibers or loosen after repeated wetting, so reject boards with cracked or visibly unstable knots for overhead work.
Vertical and flat grain: Vertical-grain faces show straighter lines and tend to move less across their width. Flat-grain boards display cathedral patterns but cup more readily, especially where sunshine dries one face while the back stays damp.
Green, air-dried, and kiln-dried: Green wood can shrink markedly after installation, air-dried stock settles near the outdoor climate, and kiln-dried material offers greater predictability for interior work. A moisture meter gives better evidence than color, weight, or storage time; learn more in this kiln-dried wood guide.
Board-foot calculations: Multiply nominal thickness in inches by nominal width in inches and length in feet, then divide by 12. A nominal 1 × 6 × 8 board contains 4 board feet, while a nominal 2 × 4 × 8 contains about 5.33 board feet.
Coverage calculations: Multiply project area by 12, then divide by the exposed board width in inches. A 100-square-foot wall with a 5.5-inch exposed face needs about 218 linear feet, or roughly 240 linear feet after adding 10% waste.
Lumber grading standards: Grade names depend on the rule book and use. NLGA, WWPA, WCLIB, and WRCLA publish or support grading information, but appearance grades shouldn’t be substituted for structural grades without design approval.
Cedar Plank Costs and Quantity
Cedar plank cost depends on species, grade, dimensions, drying, milling, location, and freight. Compare prices using the same linear-foot, square-foot, or board-foot basis rather than price per piece alone.
Typical Planning Ranges
| Material | Broad U.S. planning benchmark |
|---|---|
| Cedar fence picket | $3–$10 per piece |
| Common 1 × 6 × 8 board | $15–$40 per board |
| Common 2 × 4 × 8 board | $20–$50 per board |
| Cedar decking | $3–$8 per linear foot |
| Clear or vertical-grain specialty stock | $8–$20 or more per board foot |
These are planning benchmarks, not quotations. Local inventory, grade, species, moisture condition, length, and delivery can move the price outside these ranges.
Cost per measurement unit: Divide board price by length for cost per linear foot. For installed square-foot cost, multiply that figure by the linear feet needed per square foot; a 5.5-inch face uses about 2.18 linear feet per square foot before waste.
Price and Availability Factors
Clear vertical-grain boards command high prices because mills recover fewer long, defect-free pieces from each log. Custom profiles, kiln drying, wide stock, certified sourcing, and strict color matching also raise the usable-material cost.
Freight and hidden costs: Long boards can trigger oversized delivery charges or minimum orders. Budget for stainless fasteners, coating, primer, end sealer, flashing, furring, joist tape, replacement boards, and future maintenance labor.
- Use 5–10% waste for simple layouts with consistent short cuts.
- Use 10–15% waste for diagonals, corners, knot removal, or color selection.
- Allow 15–20% or more for complex patterns or highly selective clear work.
Total project cost equals usable lumber, waste, freight, fasteners, moisture-control materials, finish, tools, labor, and maintenance. A cheaper narrow board may cost more per covered square foot than a wider board once overlap and cutting losses are included.
Installation, Finishing, and Maintenance
Cedar performs well when installers control water, airflow, and metal contact. Natural durability can slow decay, but it can’t compensate for standing water, blocked drainage, or unsuitable fasteners.
Compatible Cedar Fasteners
Cedar extractives react with iron and can create blue-black stains. Type 304 stainless steel suits many exterior settings, while Type 316 offers better resistance near salt water; properly specified hot-dipped galvanized fasteners may suit less aggressive exposure.
Splitting prevention: Predrill near board ends, keep fasteners back from edges, and avoid crushing the face by overdriving heads. Sharp bits and cutters slice the soft fibers cleanly; dull edges leave fuzzy grain and torn pockets around knots.
Drainage and airflow: Keep end grain away from soil, standing water, and wet concrete. Follow the profile manufacturer’s spacing instructions, since cedar movement, tongue depth, hidden clips, and intended drainage gaps differ among products.
Leaving Cedar Unfinished
Unfinished cedar turns silver-gray as ultraviolet light breaks down surface lignin and rain removes the weakened fibers. Sheltered areas remain brown longer, so walls beneath overhangs rarely weather at the same rate as fully exposed boards.
Stains, paints, and sealers: Pigmented penetrating stains offer better UV protection than clear water repellents and usually fail more gracefully than thick films. Paint and solid-color systems may need a compatible stain-blocking primer to stop brown extractive bleed.
End-grain and back priming: Coat cut ends and concealed faces where the finish specification calls for it. Factory coating often produces more uniform coverage than brushing boards after installation, particularly at laps, joints, and narrow ventilation gaps.
Safe cleaning methods: Start with low pressure, water, and a coating-approved cleaner. Aggressive pressure washing tears away soft earlywood and leaves hard latewood ridges that feel corrugated under the fingertips; never mix oxygen cleaners, acids, or chlorine products.
Cedar Planks for Grilling
Cedar planks for grilling must be untreated culinary boards free from paint, stain, preservatives, glue, mold, and workshop contamination. Never assume construction offcuts or aromatic closet boards are safe for a cedar plank grill.
Buying Culinary Cedar Planks
Rather than searching for the “best cedar planks on Amazon,” choose by documented food suitability, species, treatment status, dimensions, and storage condition. Marketplace rankings and reviews don’t verify whether an unknown board is free from preservatives or contamination.
- Is the species identified?
- Is the plank untreated, unpainted, unstained, and free of glue?
- Is it represented by the supplier for culinary use?
- Has it stayed away from fuel, pesticides, metal dust, and workshop chemicals?
- Is it free from mold, rot, heavy charring, and deep cracks?
If any answer is unknown, don’t cook on it. A pleasant cedar smell can’t confirm treatment history or food-contact suitability.
Materials to avoid: Reject pressure-treated lumber, plywood, composites, glued laminations, driftwood, salvaged boards, coated cedar, closet lining, and scraps stored near chemicals. Sanding a treated or contaminated surface doesn’t make the remaining wood safe.
Soaking and Heat Control
Plank suppliers recommend soaking times from roughly 15 minutes to two hours. Soaking delays surface ignition but doesn’t make wood fireproof, so follow the plank and grill manufacturer’s directions and keep the BBQ attended.
BBQ and salmon grilling: Place the food on the clean cooking face and control heat so the underside chars and smolders without sustained flames. Salmon picks up a sweet, dry smoke aroma; bitter or acrid smoke often signals excessive charring.
Reusing grilling planks: Reuse is reasonable only when the supplier permits it and the plank remains sound, clean, lightly charred, and free from spoiled food residue. Porous wood absorbs fish and meat juices, making reliable sanitation difficult; conservative practice favors single use.
Disposal and fire safety: Let a used plank cool completely on a noncombustible surface, then soak it before disposal if embers remain. Don’t place a warm, smoking plank in a plastic bin, dry grass, compost pile, or enclosed trash container.
Cedar Problems and Prevention
Most cedar failures trace back to uneven moisture, unsuitable metal, poor coating preparation, or weak board selection. Diagnose the pattern before cleaning or replacing material, since mildew remover won’t fix iron staining or trapped water.
Failure-Diagnosis Table
| Symptom | Likely cause | Confirmation clue | Corrective action |
|---|---|---|---|
| Black stain around nails | Iron reaction | Dark halos or runoff below metal | Replace unsuitable fasteners and use a compatible wood brightener after testing |
| Brown bleed through paint | Extractive migration | Yellow-brown patches after damp weather | Correct moisture and apply a stain-blocking primer |
| Cupped boards | Uneven moisture | One face stays wetter or hotter | Improve airflow and refasten or replace severe cups |
| Soft end grain | Persistent wetting or decay | Ends touch soil, concrete, or standing water | Remove decayed wood and correct the drainage detail |
| Raised fuzzy surface | Excessive pressure washing | Earlywood erosion follows the grain | Let dry, sand lightly, and use gentler cleaning |
| Loose knots | Knot shrinkage or weathering | Cracks form around knot edges | Replace unsafe overhead boards or stabilize suitable decorative work |
| Patchy gray color | Unequal UV and rain exposure | Sheltered areas remain brown | Clean and refinish the full surface for a more uniform result |
Warping and Cupping
Warping and cupping increase with flat grain, one-sided finishing, wet installation, weak fastening, and restricted airflow. Acclimate interior stock, stack boards flat with support, and select straighter grain for wide doors, trim, and exposed decking.
Splitting and checking: End grain loses moisture faster than board faces, causing short cracks and deeper checks. Predrill near ends, seal fresh cuts where required, avoid overdriving fasteners, and cut away severe checks before installation.
Iron stains: Blue-black marks concentrated around nails, steel brackets, or runoff paths point to a metal reaction rather than mildew. Remove the iron source before treating the color, or the stain will return after the next wet period.
Tannin bleed: Brown marks through pale paint often follow damp wood, weak primer, or unsealed cuts. Let the assembly dry, correct the water source, prepare the surface, and apply the coating manufacturer’s compatible stain-blocking system.
Premature decay: Sapwood, soil contact, blocked ventilation, and end grain resting on wet masonry create early soft spots. Probe suspect areas gently; healthy cedar resists the tool, while decayed fibers feel spongy and break into damp fragments.
Uneven gray weathering: Roof overhangs, furniture, hardware, shade, and irrigation change sun and rain exposure. A perfectly uniform silver-gray surface is uncommon without cleaning and periodic finishing across the whole elevation.
Mildew and surface damage: Mildew usually follows damp, shaded conditions and surface dirt rather than deep structural decay. Use a finish-approved cleaner, rinse gently, restore airflow, and test any brightener in a hidden area before treating visible red cedar wood.
FAQs
Can Cedar Planks Be Left Untreated Outdoors?
Cedar planks can be left untreated outdoors because the wood naturally resists moisture, insects, and decay. Over time, untreated cedar usually fades to a soft gray color and may develop surface checking. Apply a UV-protective finish if you want to preserve its original color and reduce weathering.
Is Cedar Waterproof Or Does It Need To Be Sealed?
Cedar is water-resistant, not waterproof, so sealing is optional but helpful. Its natural oils help it handle rain and humidity better than many common woods. Use a breathable exterior wood sealer to limit moisture absorption, reduce cracking, and maintain the wood’s color.
How Long Do Cedar Planks Last Outside?
Cedar planks typically last 15 to 30 years outdoors, depending on climate and maintenance. Planks kept above wet soil and allowed to dry between rains generally last longer. Regular cleaning and occasional sealing can help extend their useful life.
Can Any Untreated Cedar Plank Be Used For Grilling?
Only untreated, food-safe cedar planks should be used for grilling. Avoid planks that are painted, stained, pressure-treated, glued, or sold for construction because they may contain harmful chemicals. Choose grilling planks specifically labeled for cooking, then soak them in water before placing them on the grill.
Can You Reuse Cedar Planks For Grilling?
Cedar planks can usually be reused once or twice if they remain clean and intact. Scrub the cooled plank with hot water, let it dry fully, and discard it if it is heavily charred, cracked, or smells rancid. Reused planks produce a milder smoky flavor than new ones.
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