Confused about Cedar? I am.
I was confused about what cedar is and how useful it is as a boatbuilding material. This article is a result of my notes. This is the executive summary.
Because of the large number of regional names it's often hard to figure out what you have. Many stores just sell "cedar" with no descriptions. In fact there are no native cedars in the Americas. What we know as cedar is really cypress.
Information, historical and scientific, is a bit contradictory and difficult to sort out.
As a group cedar tends to be relatively soft except for Port Orford Cedar, which is all but impossible to get hold of except out west. This means that most cedar makes for somewhat soft planks for boat building. Yellow cedar is used for boatbuilding though.
Because cedars are often very attractive colours, soft and if you get clear lumber, can be worked easily, it has been a lumber of choice for strip building of boats where strength is not important since the boat gets coated in fiberglass anyway.
As a group they are rot and insect resistant particularly if you use heartwood. Heartwood is also stronger.
The same chemicals that make cedar rot resitant also makes it somewhat toxic. Effects range from mild irritation to severe respiratory problems, skin and eye irritation, rashes, lung problems, Kidney disease and rarely possible cancer. Protect yourself if you're going to cut and sand cedar.
Previously old growth cedar provided wood that was used for boatbuilding. Now it's harder to get suitable lumber.
There are lots of records showing that cedar was widely used in the past for boatbuilding. People tended to use the wood they had around and adjusted their boatbuilding technique to suit the material. If the wood was softer and not as strong then thicker planks were used. I don't think it is an ideal boatbuilding material unless helped with fiberglass, but there are lovely cedar boats out there proving me wrong.I've made a table of different cedars characteristics. Compare at a glance.
Cedar is not cedar?
In a perfect world, I would be able to say Cedar, give the scientific name and go on to describe the uses and characteristics of the wood.
In the real world, the term cedar describes several different species and kinds of wood with more or less similar characteristics but sometimes very different ones. Even in the US and Canada and the UK the term 'Cedar' describes different species depending on where you live.
For this reason the term CEDAR is rarely used alone. Lumberyards often add terms such as: "Western Red", "Eastern red", "Eastern White" to further describe the actual species.
As far as boatbuilding goes, Cedar has a long history of use whatever the species because most of the various species of 'cedar' share some qualities; rot resistance, mostly sufficient strength, low weight, attractive colour.
It doesn't help that various lumbers are widely exported with no mention of country of origin or species available to the final user.
Some Cedar Species
Lebanon cedar, Cedrus libani
1- See bottom for photo details
You can't talk about cedar without mentioning the Cedars of Lebanon. This is the wood widely mentioned in the Bible and used throughout antiquity. Unlike all the American "ceadars" which are really cypress, it is a true cedar. Extensively exported by Lebannon, it was used by all the great kingdoms of the area. It grows in the mountain areas of the region, not only in Lebanon.
Since the forests have been heavily exploited for a long time, Lebanon cedar is no longer of great economic importance. Efforts have been made to preserve some areas. The "Forest of the Cedars of God (Horsh Arz el-Rab)" is a Unesco World Heritage Site and extensive reforestation and management efforts have been made to improve and preserve it.
It's offered by a few lumber company in small quantity. The UK grows some. It is available as an ornamental plant for landscaping.
Western red cedar, Thuja plicata
Western or Pacific redcedar, giant or western arborvitae, giant cedar, canoe cedar, shinglewood, is an evergreen coniferous tree in the cypress family Cupressaceae, native to Western North America. For many people in the US this is what comes to mind when the word cedar is used.
It's a native of the West Coast of the N. US and S. Canada. It is widespread in its area. It can grow in quite wet swampy area and is also found as high as about 7000 feet.
It has been widely introduced in other continents including western Europe, Australia, and has naturalized and is growing wild in UK.
Western Redcedar can grow to tremendous size, specimens have been found over 10 feet in diameter and over 200 feet high. It lives a long time and there is at least one tree over 1400 years old.
Like all the New world cedars it is not a true cedar but rather the largest tree in the cypress family.
It is a adaptable tree that will tolerate shade and can grow in a good range of temperatures: Zone: 5 to 7 but it does not much like high temperatures.
Western Redcedar is relatively abundant in the areas where it grows and is economically significant.
Some Characteristics of Western Red Cedar
- Dried Weight: 23 lbs/ft3 (370 kg/m3)
- Texture/Grain: Has a straight grain and a medium to coarse texture.
- Knots: Is available in many grades including with knots, clear and quartersawn
- Hardness: Western Redcedar is a soft wood that is easy to work. This also means it is easy to dent and scratch. Sanding can be uneven and create ridges where growth rings occur.
- Gluing/Finishing: There is no particular problem with gluing and finishing. Screws and Nails can leave marks and stains if the wood is outside. Staples used in Wood strip building can dent the wood. Because the wood is quite soft and not particularly strong, fasteners such as screws cannot hold hugely well.
- Colour: Can vary widely from quite pale yellowish to pinky to dark redish brown, with pronounced lines sometimes visible.
- Rot Resistance: Varies somewhat. Older trees produce thujaplicins, a group of rot resistant chemicals, in larger amounts than younger trees or later growth areas and are more resistant to rotting. There is a wide variation in the content of the thujaplicin in trees. If you are interested here is a Paper measuring the concentration in various samples of Western Red Cedar Sapwood has lowest concentration and is not rot resistant.
- Toxicity: Western Red Cedar can be quite toxic, it can be one of the more toxic woods and can cause a number of problems. It is a sensitizer which can trigger asthma and lung irritation. It can irritate the eyes and skin. More alarming, regular exposure has been linked with Nasopharyngeal carcinoma, a cancer of the nose/throat. If you plan to use cedar a lot you need to protect yourself and avoid breathing in dust.Wood allergies and toxicity chart from the wood database.
- It has the characteristic resin cedar smell.
Uses of Lumber
Red cedar was used extensively by local tribes wherever it was found along the Northwest coast (British Columbia, Washington state, Parts of Alaska). A large and rich history exists in it's harvesting, use, ceremonial uses, medicinal applications. It has a huge cultural and spiritual significance. A tremendous number of household and ritual objects were made of cedar including clothing, boats, totems, houses and medicines.
Western red cedar and other "cedars" have a long history of medicinal use particularly for fungal infections where it is used topically. Avoid ingesting in large quantities.
It is used for applications where it's exceptional rot resistance, easy of working and appearance are prized. One of its names is shingle wood and wooden shingles are widely available. Western Red Cedar Shingles Red Label in Contractor Packs [CAPITOL CITY LUMBER] Cedar is used for fencing, siding, deck lumber, outside furniture and musical instruments, and of course boat building.
Although it is too soft and weak for planking boats it is the wood of choice for strip building because it is readily available, attractive and easy to use.
Many suppliers of strip boat plans and kits also supply bead and cove cut strips. Orca boats, Noah Marine, Valley Woodworking, Westwind Hardwood, Chesapeake Light Craft. My page on strip building plans lists many plan and kit suppliers.
Since boats built by strip planking are usually covered with fiberglass and epoxy, strength is not important.
Yellow cedar, Chamaecyparis nootkatensis also Cupressus nootkatensis
Yellow cedar has many names: Alaskan yellow cedar, Nootka cypress, yellow cypress, Alaska cypress, Nootka cedar, Alaska cedar. To complicate things, it has been subject to several re classifications so it also has several latin names. Usually it has kept its nootkatensis name though.
It grows on the west coast of Canada, along the Alaskan panhandle, and North West US. The trees can live very long lives, one is 1800 years old, but they do not grow as large as the Western Redcedar.
Like the Western Redcedar it was extensively used by local Native tribes.
Characteristics of Yellow Cedar
- Dried Weight: 31 lbs/ft3 (495 kg/m3)
- Texture/grain: Straight and sometimes wavy grain is evenly textured.
- About 80% harder than Western redcedar. This means that it is not so easy to dent and scratch. This also means that the yellow cedar lumber was more suitable for boat planking. Boat building is one common use of this material. It is quite a bit stronger than most common softwoods. It also has good shock resistance.
- Like other cypresses, it has good resistance to rotting, fungal and insect damage. It is useful in applications where pressure treated lumber is not appropriate but great resistance to rotting is required.
- Glues and finishes well. Holds fasteners so it can be nailed and screwed.
- Not as common and more expensive than the Western Redcedar.
- Easy to work, not as soft as Western redcedar but about the same as black spruce, harder than white pine. Being harder, it takes a nicer finish.
- When cut it has a bitter, recognizable smell that fades with seasoning. It then smells like a raw potato.
- Valued for its uniform creamy yellow colour.
- Unlike many of the other "cedars" it is not very toxic and is rarely irritating.
Because it is relatively strong, relatively light and very resistant to rot, it is a suitable boat building material.
Eastern Red Cedar Juniperus virginiana
Like other "cedars" it has many names: Red cedar, eastern red cedar, virginian juniper, eastern juniper, Virginia Cedar, red juniper, pencil cedar and commonly, aromatic cedar.
It is a native of Eastern North America and can be found from SE Canada to Texas, and west to the prairies.
Uses of Eastern Red Cedar / Aromatic Cedar
In some conditions it can grow relatively quickly but most lumber available is quite small. It is not a hugely commercialized wood. It has found some niche applications though. Because of its attractive red colour and ability to repel insects, it is often used for lining closets and chests. The same chemicals that repel moths also make it irritating to people. It can cause skin and lung irritations. Care should be taken when working with this wood.
Because it is very rot and insect resistant it has been used a lot for fence posts. The name "Baton Rouge" literally "red stick", is derived from the native practice of marking their territory with cedar markers which are a lovely reddish brown colour.
The lumber is showy and aromatic but because of the large number of knots and sometimes very irregular grain, it is somewhat difficult to work with hand tools. Boards tend to be small. It is often made into boxes and other smaller decorative objects. It is also used for pencil making. Here is a YouTube video where they are making coloured pencils. The wood they use is cedar. Craftsmen have many uses for it including bow making.
It is one of the first tree to colonize an area after fire or in pastures. This habit of taking over pasture land makes it an invasive species from the point of view of farmers and ranchers. In the past the regular prairie fires would control the trees but more recently, roads and clearings have reduced fires and increased the growth of the aromatic cedar.
Because it's a tough tree that is capable of growing in many different conditions (except very wet ones) it is a good landscape candidate. It is also quite salt tolerant. One problem with it is that it can carry the cedar-apple rust so don't plant it near apple orchards. Here is a link to US dept of Agriculture and Forest.
It is not a very useful wood for boatbuilders because it is knotty and larger clear boards are harder to come by. The clear wood, or wood with solid knots if it is available is suitable. Small boats have been successfully made from it. It has good hardness.
Northern White Cedar Thuja occidentalis
Northern White cedar is also known as eastern arborvidae, white cedar, swamp cedar, eastern cedar, american arborvitae, arborvitae. It is not the same as the Australia white cedar.
It is native to SE Canada and adjacent US states. Strands can be found as far south as North Carolina and Appalchians, and has been seen as far north as the arctic tree line. It is happy with wet feet and is often grows in swampy areas. They are also often seen hanging on to cliff edges. Northern white cedar can live a long time. A dead tree with 1650 growth rings has been found. Because they grow in cool often difficult places, they don't grow very large usually.
Northern White cedar was very useful historically to local native tribes and has, like it's western counterparts, a vast lore associated with it.
Of particular interest was its widespread use for making birch bark canoe ribs and planking. Later the wood was used for canvas canoes.
Characteristics of Northern White Cedar
- Dried Weight: 22 lbs/ft3 (350 kg/m3)
- Texture/Grain/Colour: Pale brown, tan with sapwood paler. Straight grain with fine texture. Usually many small knots.
- Rot/Insect Resistance: It is quite a durable wood and resists decay and many insects including termites.
- Strength and Workability: Northern White Cedar is not a very strong wood being less so than western redcedar. It is not difficult to work but because it is soft, it does not hold fasteners very strongly. It glues well.
- It has a cedar-like smell when cut. It is not as strong as aromatic cedar.
- Toxicity: Like many of the other "cedars" it can cause irritation and allergic reactions. It can be damaging to lungs with prolonged exposure.
Uses of Northern White Cedar
Because of its resistance to rot and insects, it was used for fence posts, construction including log cabins, shingles, railroad ties. It is harvested along with other trees for paper making (pulp)
Light and rot resistant, it is useful in boat building. It is not a very strong wood however. Ausable River Boats were traditionally made of northern white cedar and pine. Canoe often had ribs and planking made from Northern white cedar.
2x4 construction "Spruce" often has the odd board of white cedar included. Look for the darker lighter boards and sniff them out.
Northern white cedar is widely used as an ornamental with many cultivars having been developed. In my area, Emerald green is a common sight and grows well.
Cedar leaf oil is distilled from leaves and used in medicines and perfumes
Several animals also like to eat it, white tailed deer (is there anything they don't like?), porcupine, red squirrel, hares.
Here is an article by the BorealForest.org at Lakehead University.
Atlantic White Cedar Chamaecyparis thyoides
The Atlantic White Cedar has many names, atlantic white cypress, southern white cedar, whitecedar, false-cypress are a few.
It is a native American tree found along the East coast between S.Maine and Georgia, and on the Gulf of Mexico. It lives in forested wetlands. Because readily available trees have been harvested and remaining populations are in swamps they are hard to harvest so it's use as lumber is not as important as in the past.
Atlantic White Cedar grows to about 100 feet in height. Even though they can live to an amazing 1000 years old, it does not grow after the first 100 years. They tend to get blown over because of shallow roots.
Characteristics of the wood
- Dried Weight: 24 lbs/ft3 (380 kg/m3)
- Hardness and strength is similar to other "cedars"
- Like other Cypres it is resistant to rot. The heartwood more so than the sapwood
- Appearance: Has a reddish brown heartwood while the sapwood is paler and ranges from dark yellow to almost white.
- Grain is straight with uniform fine texture.
- Easy to work, can be glued and finished. Because it is not hugely strong, it does not hold screws or nails as well as harder woods.
- Smell/toxicity: It smells like what we expect cedar to smell like, and can be slightly irritating. It is not as toxic or likely to cause respiratory irritation as others.
Uses of Atlantic White Cedar
Old growth wood has been used a lot for boatbuilding. Because of its small range and small size, suitable lumber is quite expensive.
Smaller trees are used as construction lumber, shingles, siding, and carving.
Here is a Youtube series of Videos describing in detail the making of A Workskiff, by Shipwright Louis Sauzedde sponsored by Jamestown Distributors. He talks about the side planks at 5:30.
Port Orford Cedar Chamaecyparis lawsoniana
Also know as Lawson Cypress, pacific white cypress, it is difficult to get and expensive, This cypres makes a great boatbuilding lumber but demand greatly exceeds supply.
It occurs in the the North West US, Oregon and North Western California.
The tree can grow to 200 plus feet and can grow to 5 or more feet in diameter.
Characteristics of Port Orford Cedar
- Dried Weight: 29 lbs/ft3 (465 kg/m3)
- Hard, light and very strong.
- Available in large size pieces with few knots.
- Grain/Colour: Grain is very straight and uniform. Colour is pale yellow-brown to almost white.
- Rot resistant and resistant to most insect attack. Also resistant to acid corrosion.
- Easy to work with, stains, glues and finishes well.
- It has a pungent spicey scent which has been compared to ginger.
- Can be quite irritating and many people who work with it can suffer skin irritation, asthma like symptoms such as difficulty breathing and runny nose. Long term contact is known to cause kidney disease and allergic reaction are possible.
- Has been seriously threatened by a fungal disease caused by Phytophthora lateralis, that attacks the roots, spreads to the trunk at the base of the tree and eventually kills it. Because of this and because it has been over harvested it is listed as Near Threatened.
- Like other cedars it is highly regarded and used by native tribes of the area.
Uses of lumber
Prized for its strength and decay-resistance it makes a great boat building lumber. Widely used architecturally. Japan imports large quantities.Bear Creek Lumber supplies Port Orford Cedar, as does Metcalf Sawmill Products.
Because of its qualities it can be used in furniture making. It stains and works well. It has also found a niche market in casket making.
The wood is also used for instruments such as guitars. In the past arrow shafts were made from the straight grained wood.
The attractive tree has been used in landscaping and several varieties have been developed. It is quite tolerant of growing conditions but requires a regular supply of moisture during the growing season. At Christmas time, the attractive lacy boughs are popular.
Incense Cedar Calocedrus decurrens
2-Photo attribution at the bottom of page
Also known as California incense cedar, California White Cedar, the Incense cedar is a member of the cypress family that can grow to 150 feet, but is more likely less than 90. It grows along the American west coast from British Columbia Oregon to Baja California. It is tolerant of conditions including summer drought. Often found at mid to high elevations.
Characteristics of Insense Cedar
- Appearance/Colour: Heartwood is coloured light to medium brown/red. Sapwood is lighter tan and sometimes pinkish.
- Wood can contain pockets of fungus decayed wood referred to as peck. In general the wood is considered durable.
- Grain is very straight with a uniform medium/fine texture that is easy to work, glue and finish. Once dried it is very dimentionally stable.
- Odour/Toxicity: Incense Cedar has a pleasant spicy cedar smell. Many people would recognize it as the smell of newly sharpened pencil, since the wood is used for pencil making. Like many other cyprus it is irritating and can trigger allergic reactions, rashes and irritations.
- Dried Weight: 24 lbs/ft3 (385 kg/m3)
- Although stronger than western red cedar it is not very strong and has low shock resistance and stiffness.
- Many knots make for attractive decking but clear lumber is at a premium.
Incense Cedar Lumber uses
Number one lumber for pencil making because of straight easily sharpened even grain. It is also in demand for the lath of window blinds. One of it's main use is as fenceposts because of its high rot resistance. For the same reason it is made into outdoor furniture, trellises, paneling, grape stakes. It's attractive colour makes it a wood of choice for novelty items and caskets. It is also used for moth proofing chests and closets.
As with other cedars it is used for decking and decorative wood structures.
IF you can get your hands on Incense Cedar in relatively clear boards it can works for boats, particularly if you are doing a strip canoe that will be clad in fiberglass. A few small knots don't matter. Since there is quite a lot of variation in the strength of wood depending of speed and conditions of growth, grain, and location of tree you need to test any wood that will be used for planking. Heartwood is better than sapwood.
Plywood has replaced solid wood for planking
With the depletion of large boards suitable for planking of boats, and the increasing high price of available stocks, plywood has mostly replaced solid wood planking.
This article is a work in progress. To be Continued...
Photo Attributions1- Cedars of God attribution BlingBling10 at the English language Wikipedia, CC BY-SA 3.0, Link
2- Attribution: Photo of incense cedar comes from Hansen's Northwest Native Plant Database under GNU copyright email me if you find mistakes, I'll fix them and we'll all benefit: Christine