Glulam Timber Species: Which is better Pine or Spruce?

Do you think we’re talking about Redwood, Pine or both?

Relax. You’re reading a blog article, not a quiz. But well done if you knew European Redwood and Pine are one and the same, European Redwood is a trade name for the species Scots Pine.

We’re going to refer to it as pine for this blog – but what is the difference between pine and spruce? How do you know which is right for your glulam project? Here are some details you might find useful…

Where does pine come from?

Pine is grown in the UK but can be found all over the northern hemisphere.

Scots pine is the only truly native pine in the UK. It provides protected habitats for rare mammals, including red squirrels, pine martens and Scottish wildcats. You might think these timber naming nuances would have been smoothed out by now, since Pine trees have a lifespan of up to 700 years!

You may be aware of our commitment to local sourcing, wherever it makes environmental and commercial sense. Our UK-sourced timbers tend to be Douglas Fir, Larch or more recently Ash, while UK-grown spruce and redwood are available, we tend to source these mainly from Scandinavian countries, Germany and Austria.

What does Pine glulam look like?

The trade name of redwood a bit misleading because it’s quite light in colour, so can be quite close in appearance to Spruce (also known helpfully as Whitewood). Larch or Douglas Fir glulam have a more of reddish-pink colour.

You will find more colour variation overall in pine. The heartwood (middle) is darker than the sapwood (outer), so pine glulam can be recognised by its slightly stripy variations. You’ll also see this variation in the knots within the wood – they tend to be darker in pine than in spruce.

Pine lends itself nicely to a wider range of visual grades. So, in practice, you’ll be able to source knot-free or almost knot-free pine as it is commonly stocked.

What does ‘Unsorted Grade Pine’ mean?

If you want a ‘knot-free’ aesthetic, you’ll want to specify Unsorted Grade Pine. It is an industry term which comes historically from when inferior or defective wood was sorted and removed, leaving the higher-grade wood. The wood remaining was of a higher quality, with few or no knots. It was ‘unsorted’.

You’d be forgiven for thinking ‘Unsorted Grade Pine’ sounds inferior, but in fact, the opposite is true! ‘Unsorted Grade Pine’, has a very low knot content – we know this appears counter-intuitive at first, we can’t change the industry terminology, but we can make sense of it for you!

By comparison, the industry doesn’t cater for visually graded Spruce in the same way, which means pine is an attractive choice when knot-free joinery and glulam is requested. Be aware that requesting this though will affect your price point.

What are the differences in strength between pine and spruce?

Both pine and spruce can be engineered to meet industry-standard strengths, but there are some differences.

Spruce has an increased strength-to-weight ratio, meaning it may be better suited to some projects, for example where space is limited.

You can also more easily access higher-strength grades with spruce. The reason is availability – because spruce is more commonly used, the pool to pick the ‘best’ wood from manufacture is larger. Put simply, it’s easier to find spruce timber ready to be manufactured into higher strength grades.

While spruce is more readily available in grades GL24 to GL32, pine glulam is less common, so we’d recommend designing to GL24 to maximise availability.

What about durability and external use of pine or spruce?

Pine is denser and more resinous than spruce, making it marginally more durable, but neither are recommended for external glulam structures.

While there are ways you can protect glulam from the elements (see our blog on designing for external glulam projects), we’d only ever recommend internal use for both these timbers.

Another property of pine is it takes on treatment more easily than spruce, meaning that it is more effectively pressure treated. Pressure treated pine glulam is possible to source but not a common thing for us to manufacture.

How do costs compare between pine and spruce?

Spruce benefits from high use. It’s the most commonly used timber for glulam, probably accounting for 80% of sales across Europe. It’s readily available, so generally offers shorter lead times. Nearly all glulam manufacturers will offer spruce but not all will offer pine and if they do, lead times for pine may be longer. 

And, as you’d expect, costing for pine is linked to the visual grading. Lower grade pine can be cheaper than spruce, but knot-free pine could be over 50% more expensive (our Glulam Cost Estimator will help you compare).

Some manufacturers won’t offer pine, so it’s a case of whether the knot-free aesthetics, colouring and durability outweigh any potential difficulties in sourcing or lead times.

If you’d like to see some examples of pine projects we’ve worked on, look at the RNLI Lifeboat Station in Wells-Next-To-Sea, and the ‘Ugly House to Lovely House’ project which was featured on Channel 4.

For spruce projects, check out Rawlings, Bristol and Sherborne House.

For advice on any of the above, or for help with your next glulam project, just pick up the phone or drop us a line – get in touch.