Ever wondered if alder is a hardwood or a softwood? From its surprising hardness level to its versatility in projects, I’m unpacking everything you need to know.
QUICK ANSWER:
Alder is a hardwood, known for its light brown color with yellow or reddish hues upon air exposure. It has a subtle grain and is softer than many hardwoods, with a Janka score of 590. Alder is versatile, ideal for cabinetry and trim work.
Alder Wood Characteristics
Alder is almost all white when it is first cut, but exposure to air turns it a light brown color with aspects of a yellow or reddish hue. Its grain pattern is subtle and fairly straight, more so than other hardwoods, and uniform in texture.
Its heartwood forms only with advanced age, and there is little differentiation between sapwood and heartwood even then. Its straight grain helps it maintain shape without warping or twisting.
Working With Alder Wood
Alder takes to machine work well and is well-suited for turnery (lathe work). It also takes nailing, screwing, and glues quite well. It is easy to sand smooth, and when stained, it pairs well with walnut or cherry. It can also be painted to a good finish. It dries and cures easily and with no degradation in its dimensional stability.
However, alder is a relatively soft hardwood and has only a medium density. As such, it has a low bending strength for a hardwood, and does not stand up well to shock – it dents easily.
All of these considerations, though, make it a suitable choice for items like baseboard, crown molding, milled window and door trim, and more. Its inherent straightness makes it a perfect choice for such uses.
It doesn’t stop there, though:
- Cabinet faces and doors to birch plywood cabinets
- Doors
- Shutters
- Furniture
- Kitchen utensils (spoons, salad tossing forks, for instance)
are all on the list of good uses for alder. As we mentioned, it stains well, can be painted to a good finish, and matches well with other hardwoods. When prime alder is used for these projects, you will not likely find defects or blemishes in the wood – no knots, splits, or cracks.
Some woodworkers consider alder to be a bit bland to work with, with a subtle and straight grain and a less than brilliant color, but it actually can be quite beautiful to work with because of these finish qualities. When staining, don’t let the stain sit on the surface long before wiping away excess, as it will become patchy and darker.
Its pores are open and will suck the stain deep into the alder wood, so be careful with your stain application. However, once stained to your satisfaction, alder will also absorb a lacquer coat well and deeply into those same pores, providing your project with a glassy coating.
Alder is also a good choice in cabinetry work. It’s a wonderful face-frame material on a birch plywood cabinet and matches well with its relative, birch wood. What’s even better is that alder is about half the price of birch. As such, it’s a favorite of cabinet makers because of its easy workability, favorable price point, and its compatible aesthetic to birch.
We also came across something interesting in our research for this article. Because of its straightness, weight, structural integrity, and soft pricing, it is used in first-stage framing for RVs. A thin overlay of cherry, oak, walnut, or birch will cover that inside framing to give the RV an external appearance of richness. It reminded us of the rubble that is used behind the fancy facade of stone walls – cheap, structurally sound, and hidden.
Believe it or not, after telling you of all these other common uses, alder is also considered a good firewood for stoves or fireplaces. It’s easy to split, and if properly dried and cured, it will burn cleanly and has a pleasant scent.
Alder On The Janka Scale
When we refer to hardwoods, we are generally referring to various species of deciduous trees – trees that shed their leaves in winter. All hardwoods come from these trees, but not all hardwoods are, in fact, hard.
Hardwoods grow slower than softwoods, and most hardwoods will have a higher density than softwoods. Hardwoods include maple, oak, walnut, and, in the case of today’s article, alder.
Softwoods, on the other hand, come from coniferous trees – evergreens that don’t lose their leaves in winter. All softwoods come from these trees, the cones and needles kinds of trees, and will have, in most cases, less density than hardwoods. Examples include pine, spruce, and fir.
Not all hardwoods are harder than all softwoods, as paradoxical as it may seem to say. To make these distinctions clear, we can turn to the Janka Scale.
The Janka Scale
The Janka Hardness Scale was created by Gabriel Janka as a means of measuring the hardness of wood. It does so by measuring the degree of resistance to pressure and denting.
The force required to embed a .444” steel ball halfway into a wood sample gives the Janka score. Obviously, the harder and more dense the wood, the greater pressure will be required.
Alder And The Janka Scale
We’ve mentioned some hardwoods and some softwoods in this article. To show you where alder fits in the scale, we prepared this graphic to place it among some softwoods and hardwoods.
| Wood | Janka Score |
|---|---|
| Basswood | 410 |
| Aspen | 420 |
| White Pine | 420 |
| Alder | 590 |
| Douglas Fir | 660 |
| Mahogany | 800 |
| Cedar | 900 |
| Walnut | 1010 |
| African Mahogany | 1100 |
| Birch | 1260 |
| Red Oak | 1290 |
| Lignum Vitae | 4400 |
We’ve written of aspen, southern yellow pine, and others on this chart and thought you would find it interesting to see how alder stacked up against them.
As you can see, alder is harder than aspen and white pine but softer than southern yellow pine and substantially softer than its relative, birch, or the other hardwoods (cherry, walnut, red oak) mentioned. We added Lignum Vitae to show you the hardest of woods according to the Janka Scale.
We looked at quite a number of videos for you today, and we found one in particular that not only worked with alder but also presented an interesting finishing technique. The videographer took advantage of alder’s softness (even though it’s a hardwood) and lack of resistance to denting to give the workpiece a distressed look.
You can see how easily he created that distressed look – a bag of rocks, a knife, an awl for worm holes – taking advantage of the softness. He also used several layers of finish and stain to add color and character to the wood. The finished product is quite lovely, and the alder lived up to its reputation for taking color well and easily.
While we in the east don’t see a lot of alder available commercially (usually will require a special order at the lumber yard), we hope someday to work with it on a project. Matching it up with other woods in a project might be a lot of fun.