Not all woods are naturally resistant to rot. Most softwood species are non-resilient. These include pine, maple, birch, aspen, beech, alder, hemlock, poplar, etc. This makes them not very suitable for exterior projects.
Some species of wood are naturally rot resistant due to complex chemical compounds that they evolved to protect themselves against decay. Well-known domestic examples include cedar, redwood, old-growth cypress, mulberry, yew, osage orange, and black locust.
The Best Water-Resistant Wood Types and Species. Iroko, Oak, Western Red Cedar, Cherry, Maple, and heat-treated woods are a few examples of timber with excellent dimensional stability and high resistance to warping and shrinking in the face of moisture.
Which Wood Lasts the Longest? Teak wood easily lasts the longest when used for outdoor furniture or decking.
First, the sapwood (wood closest to the bark that tends to be lighter in color) of most trees, even highly decay-resistant species, offers very little decay resistance. If a piece of lumber has much sapwood, it won't last as long outdoors.
Most experts are of the opinion that the Australian Buloke, which is an ironwood tree, provides the hardest wood in the world, with a Janka hardness rating of 5,060 lbf.
White Pine / Red Pine / Southern Yellow Pine
Not naturally resistant to rot or insects. Kiln-drying typically used to kill existing insects in wood. Requires preservative treatments to prevent future rot and insect damage. However, these treatments lose their abilities once the logs crack, opening up unprotected areas.
Cedar wood projects typically last more than 20 years without splitting, rotting, or warping. White oak and teak are also long lasting woods that are resistant to decay, twisting, cracking, or warping.
Australian Buloke – 5,060 IBF
Known as the hardest wood in the world, this particular type has a Janka hardness of 5,060 lbf.
Heirloom-quality handmade wood furniture should last more than a lifetime. In fact, it can last for decades if properly maintained. This type of wood furniture is more likely to reach the “antique” milestone, meaning it can last 100 years or more.
Naturally resistant woods that are commercially available include black locust (Robinia pseudoacacia), teak (Tectona grandis), ipe (Tabebuia spp.), California redwood (Sequoia sempervirens) and bald cypress (Taxodium distichum). These have the highest resistance to rot over time.
Cedar is a type of wood that is known for its durability and resistance to rot, making it a popular choice for outdoor structures such as fences and decking. However, cedar is not immune to rot, and eventually, even cedar posts will deteriorate over time.
Redwood and cedar naturally contain tannin (a chemical that gives the products their color), which keeps the wood insect resistant. Since Californian redwood has a higher level of tannin, it could be more rot resistant than cedar.
While redwood or teak certainly qualify, five more common lumber species that also stand up well to sunlight, moisture and wood-boring insects are Western red cedar, Spanish cedar, cypress, white oak and mahogany. Red cedar tends to be knotty, but it's affordable and widely available.
Because of the size and straightness often found in Poplar logs, it is no wonder why the pioneers preferred this timber for log cabin construction. It is also highly rot resistant, which is why many barns were sided in the last couple centuries with Poplar lumber.
Of locally available woods, Black Ironwood is typically the strongest type of wood you can find in America. It's found in Florida and has a 3,660 lbf (16,280 N) Janka rating. Other strong North American woods include species of hickory, maples, oaks, walnuts, and beeches.
Characteristics of balsa wood make it a unique hardwood albeit, when weight for weight basis is excluded, it is the weakest of all commercial species.
Pine is a super cheap wood that is actually quite strong for its price. Pine is very common for furniture building, and most of our early builds were made from pine. We still use pine sometimes, especially if we plan to paint the project.
For example, Teak doesn't need any treatment which prolongs its lifespan because it is naturally durable and doesn't have much movement whereas kiln dried Oak does need treating to prevent it from: Losing moisture and shrinking in the summer.
Naturally Resistant
To deter the pests, homeowners can obtain heartwood-grade lumber for construction projects. Termites also tend to avoid specific species of trees such as redwoods, yellow cedar, Laotian teak, and cypress. However, these types of wood are not as long-lasting as treated lumber.
The finished result – often referred to as ore-pine or cured pine – is the material that you usually find in the many ancient wooden buildings – in Norway and in other places around the globe. Wood that will last for a thousand years and more.
Iroko, Oak, Western Red Cedar, Cherry, Maple and heat-treated woods are just a few examples of timber that boast excellent dimensional stability and high resistance to shrinking and warping in the face of moisture. To maximise their performance, these woods can be further treated with a sealant.
This is caused by the oils and acids produced by both wood species. These are known scientifically as “polyoxyphenols” which give cedar its distinctive and pleasant aroma. The “phenols” also are responsible for Cedar's natural resistance to moisture, decay and insect infestation.
Resistance to Rot and Decay
There are those magical natural oils in cedar that make it resistant to decay and help repel pesky bugs from taking up shop. Plus the oils make cedar smell good. Pine does not naturally resist decay, and it is pressure treated to make it more durable outdoors.