Is Spruce a Softwood Or A Hardwood?

Is Spruce a Softwood Or A Hardwood

Today we’re going to spruce things up a bit – you know, make it neat or smart in appearance.  That’s an old phrase that goes back to the 1300s, when the term for Prussia was Pruce, according to our research for this article.

By sprucing up, we mean we’re going to discuss spruce trees, spruce wood, and spruce lumber and give you a sense of how it is used and could be used in your woodworking shop.  It’s light in weight, stable, and moderately rot resistant, and as a softwood, it’s also easy to work with and takes to tools well. 

Spruce Trees

Spruce is an evergreen tree, coniferous (it grows cones), and grows fairly quickly at a pace of between 8 – 12 inches per year.  The Norway spruce, though, will grow 2 -3 feet per year and, in good weather, will grow even faster, up to 5 feet per year. The tallest species of spruce is Sitka spruce, and these trees can grow as tall as 250 – 300 feet when fully mature. 

Other species of spruce trees, genus Picea, include:

  • Norway spruce.  Brown to reddish-brown heartwood surrounded by white sapwood and a Janka rating of 380.
  • Blue spruce (think Christmas trees)
  • Black spruce.  A pale, yellowish-white heartwood and a Janka rating of 520.
  • White spruce.  Pale heartwood with a yellowish tint and a Janka rating of 480.
  • Red spruce.  A red to yellow heartwood and a Janka rating of 490.  
  • Engelmann spruce.  A yellow to white heartwood and a Janka rating of 390.

The latter species, Engelmann spruce, is the slowest-growing of spruce species, having adapted to the colder and harsher environments in which it grows, including northern North America.  Its rate of growth limits it to about 4 – 5 feet after 20 years.

Part of the Pinaceae family of trees, its relatives include pine, firs, including Douglas fir, cedars, and hemlocks.  All of these trees are softwoods, along with spruce, and share many of the same characteristics.

Spruce Tree

Spruce trees require no care or pruning and tend to grow upright naturally, and form a pyramid as they do.  Again, think Christmas trees.  With that tendency to grow upright, lumber from spruce will tend to be straight, and a spruce tree can generate straight lumber in an efficient way.

The Janka Scale, developed by Gabriel Janka, measures the force necessary to embed a half-inch steel ball halfway into the wood being tested.  The score or rating is the lbs of force necessary to do that.  To give you some idea of the softness of spruce as compared to others, red oak has a Janka rating of 1,290.  The hardest wood is Australian buloke, with a Janka rating of 5,056.

What is Spruce Wood Used For?

As is generally the case with softwoods, spruce is readily available and at an affordable price.  Since the trees grow quickly, there is a good supply that does not task its eco-friendliness or hurt the availability of the trees.

The spruce wood is easy to handle and work with, as is common with softwoods.  You’re probably experienced working with pine, and spruce is no different.  Like other softwoods, too, spruce wood is easy to shape – it’s bendable with a little steam and can take almost any shape you might want for a home woodworking project.

Musical Instruments

That last quality leads nicely into using spruce for the making of musical instruments. Those instruments include violins, the tops of guitars, and for piano sound boards.  

Spruce trees have closed growth rings that make it a great tone wood, and that gives a sound texture that is unique among other softwoods.  Instruments made from spruce wood have a tonal quality that enhances all sound coming from them.

Paper Products

As with other softwoods such as pine and fir, spruce has a cellulose fiber that lends itself well to the making of paper and paper products.  Those long fibers will form together to give paper enough texture and strength to hold together well, even in thin sheets.  

Crates and Boxes

Spruce wood is somewhat stiff and, as previously mentioned, is also straight, both qualities that make it a good choice for crates and boxes.  Its light weight also makes it easy to handle and move.  Finally, its affordable price justifies using it for such utilitarian projects.

Boats and Planes

Perhaps you’ve heard of the Spruce Goose, the largest plane ever built.  It was designed and constructed by Howard Hughes and flew exactly once.  

Spruce is strong enough and more durable than you might expect.  Early biplanes and even military fighter planes during the World Wars were made using spruce wood.  It has a moderate resistance to rot and decay and was sturdy enough to get planes into the air and stay there.  Boats will often have some spruce in them, too.

Construction Projects

The most common use of spruce wood, though, is in construction.  Just as pine is a common framing wood in home construction, so is spruce.  Its straight and stiff qualities make it suitable for this purpose.

Spruce plywood is also common in construction projects.  It’s strong, stable, and light in weight, and its use in home construction includes roofing, walls, and flooring underlayment.  It is always available and fairly inexpensive, so it makes sense as a construction material.

For the home woodworking shop enthusiast, it is interchangeable with pine.  It stains well and gives a warm appearance if finished well.

Strengths and Weaknesses of Spruce Wood

As a softwood like pines and firs, it shares in common with them the same strengths and weaknesses in its use.  

  • On the plus side, spruce wood is inexpensive and always available; its grain is uniformly straight and has an even texture; it’s easy to work with, as are all other softwoods; and its heartwood is moderately rot-resistant. 

Additionally, it is easy to work with, shape, and bend.  While you might encounter knots in the wood, and if you work regularly with pine, you know how to work around or with the knots to give your project a good appearance.   

  • On the minus side, spruce wood is not as durable as hardwoods, but that is the case with all softwoods; because it is not as durable as hardwoods, it will require more frequent maintenance to extend its lifespan, and it is susceptible to insect attacks, making it unsuitable for outdoor projects unless treated.

    Pressure-treating spruce wood, though, increases its cost.  At the least, any outdoor use will require tight sealing to protect it from the elements, although other woods are better choices for outdoor use.

Another minus is the occasional splitting while working with it.  Again, if you work with pine regularly, you’re familiar with this and know how to handle it properly.  

  • Staining spruce wood will require a bit more attention.  It’s a light-colored wood, so can take a light or a dark stain, just like pine.  But, its grain is open and large, and staining can be uneven or blotchy.  Be sure to use a pre-stain conditioner that will slow the absorption of the stain for a more uniform appearance.

It probably isn’t necessary to mention that spruce wood is not waterproof.  It is a softwood and has an open and large grain that will soak up water quickly.  Not even hardwoods are fully waterproof, though, so this is not a big deal or something experienced woodworkers would expect.  

The Spruce Goose

We mentioned the Spruce Goose earlier, the one flight in a lifetime plan designed and built by Howard Hughes.  You’ve seen plenty of videos about working with wood, and we thought something just a little different might be interesting.  

This video shows the one and only flight of the plane and a little bit about it.

YouTube video

If you’ve worked with pine, you will know what it’s like to work with spruce.  For most projects, these two woods are interchangeable.  You’ll know what to expect and will find spruce to be an easy wood to work with for all of your pine projects, too.