Botanical Name: Alnus
Alder is a North American hardwood usually found in the Pacific Northwest, generally between California and Alaska. While there are many species of alder throughout the world, the most commonly used in woodworking today is the red alder. In the flooring industry, hardwood harvested in North America is referred to as domestic, which is less expensive than the imported exotic hardwoods. Alder has a consistent coloring throughout ranging from white to a pale rose-brown depending on the specific variety. Alder trees mature between 25 and 40 years, however, after about 70 years, the quality of the tree begins to decline. The average height for a mature tree is 90 feet.
Prior to their introduction into North America, a variety of alder trees were located throughout the world in areas ranging from Europe and Siberia to Iran and North Africa. Ancient myth tells of the black alder trees that hid a king in the forests of Scotland. From myth into reality, the alder wood was used during the Bronze Age to create wooden strongholds in Scotland. The alder wood was perfect for this as it became incredibly strong after being exposed to water. Throughout the Industrial Revolution, alder was used for locks and canal moorings. In fact, much of Venice is built atop piles made from the trunks of alder trees. Interestingly, the recommendation remains that alder logs be stored in water if they cannot be processed quickly. Of course, the preferred method today is for the wood to either be air-dried or kiln dried quickly to prevent unsightly stains.
The durability of a hardwood floor is in determined, in part, by its Janka rating. With zero being the softest wood and 4000 being the hardest, a good flooring option is somewhere in the middle. Keep in mind that a rating of zero would be entirely too soft, however, a rating of 4000 would be much too hard to mill into flooring. The Janka rating for red alder, the most commonly used in flooring, is 590. This is why alder hardwood floors are recommended for homes where a rugged floor is acceptable. Even following all precautions and maintenance guidelines, this flooring will show a bit more wear and tear than floors made of hardwood that ranks higher on the Janka scale.
Alder is easily machined and turned. The wood can easily be nailed, screwed, or glued, making it a good choice for a variety of hardwood flooring styles. The wood is able to be finely sanded and finished to a smooth grain. This allows the wood to accept paint readily and also to easily accept a variety of stains. When stained, it can easily blend with mahogany, cherry, or walnut. Because alder is often a less expensive option, people who like the color of the other hardwoods can incorporate that into their interior design plans at a reduced cost. There is very little degradation during the drying process, and dimensional stability remains constant after drying. Alder has a medium density and is somewhat of a soft hardwood. It is lightweight and has a low stiffness and shock resistance.
Where to use
Alder is very popular in the furniture industry because of the uniform color, texture, and elasticity. These same characteristics are quite prized in the flooring industry as well, making alder an excellent choice for those looking for a beautiful hardwood floor. Alder is somewhat lightweight and has a moderate strength. For those who like a rustic, lived in feel, alder is ideal for almost any location suitable for other hardwood floors. However, because it is a bit softer than some of the other options available, high traffic areas such as foyers and hallways are not suggested for homes that do not wish to have the more lived-in appearance. As with any hardwood floor, areas that are frequently exposed to standing water such as bathrooms, kitchens, or mudrooms should be avoided. Good locations for alder flooring include bedrooms, dens, and living rooms.
Care and Maintenance
As with all hardwood, care must be giving in maintaining the appearance of alder flooring. Prevention is the key to keeping a hardwood floor looking spectacular. Pads should be placed under the legs of furniture and runners used in areas that will receive a lot of traffic. Animals’ nails need to be trimmed to prevent gouging of the floor, and shoes with heels need to be removed before walking on the floor. Another factor to consider when caring for a hardwood floor, regardless of the type of hardwood used, is the finish that was applied. Different finishes will require different care techniques. Some cleaning guidelines remain constant for all types of hardwood floors. Sweep the floor regularly and be sure to promptly clean any spills to prevent a stain from soaking into the wood.
Alder is extremely valuable to the environment. The species grows quite quickly even in areas that have been harmed by natural disaster, burning, or mining. This makes alder ideal as windbreaks near farms and as an introduction of biomass to devastated areas. Their leaves create rich compost, and the symbiotic relationship between alder and a nitrogen-fixing bacteria converts nitrogen from the atmosphere into nitrates for the soil. These nitrates are used by the alder and also enhance the fertility of the soil. Additionally, the alder catkins are an excellent source of pollen for bees, especially honeybees. Because this is one of the first sources available in the spring, it helps the bees recover from the winter. Alder is also a food source for some moths and butterflies.