Tag: commercial construction

Choose Black Spruce

Posted on by Gary Snider

Cornerstone Timberframes delivers mass timber structures that meet the highest standards of performance, sustainability, and aesthetic value. In collaboration with our supply partner, Nordic Structures, we proudly utilize black spruce for our mass timber elements — a material that continues to prove itself as a superior and cost-effective alternative to Douglas Fir.

Why Black Spruce?

  1. Reduced Cost Without Compromise

Black spruce offers structural strength ratings equivalent to Douglas fir at a lower material cost. This creates notable savings, particularly when scaled to larger commercial, institutional, or residential builds.

  1. Superior Dimensional Stability

The tight grain and small laminations in black spruce glulam result in increased dimensional stability, reduced checking, cupping, and twisting over time. 

  1. Improved Colour and Appearance

Black spruce is known for its uniform appearance and light colouration.  Its superior ability to receive stain and faithfully render colours makes for creative freedom and a higher architectural appearance. In comparison, fir’s red undertone and tendency to have light and dark alternating stripes create aesthetic limitations.

  1. Locally Sourced & Sustainably Harvested

Grown and manufactured in Canada, black spruce is a renewable resource harvested from well-managed forests in Quebec. Both Cornerstone Timberframes and Nordic Structures are FSC® certified, choosing to follow the most rigorous sustainable forestry program in Canada.

  1. A Decarbonizing Hero

Black spruce is uniquely suited to help Canadians decarbonize construction.  At about age 80 black spruce is mature and begins to decline in health, moving from absorbing carbon to releasing it back to the atmosphere. Nordic harvests mature black spruce, locking their carbon into durable mass timber products. In contrast, Douglas Fir trees live for over 300 years, absorbing C02 throughout their long lives.  It is vital to preserve long-lived trees as carbon sinks if we hope to reach a carbon-neutral future.

The Unlikely Hero of Mass Timber

Posted on by Gary Snider

This feisty little tree grows throughout the northern regions of Canada. It survives harsh conditions, long, cold winters, and short 60-day growing seasons. 

Black spruce thrives in low, boggy landscapes. It reaches maturity at around 80 years and can live up to 120. Under ideal conditions, it can reach 30 metres into the sky and grow up to 36 centimetres across. But this is rare.  Most black spruce will top out at 20 metres (65 ft) and have trunks only 11-15 cm (4-6 inches) in diameter.

Black spruce is well-adapted to wildfires and is one of the first trees to return after a fire. Rather than dropping cones, it holds them in its uppermost branches where they can remain unopened for years. The cones are rigid, resisting weather, squirrels and insects, opening only slowly over time, or quickly when heat from fire softens the cone scales to release the winged seeds.

These cones, held for years, await a fiery dispersal and the start of a new forest.

So far, none of this seems very heroic. In fact, it’s almost surprising that the black spruce is even considered for construction. But here comes a plot twist: small is beautiful, slow is strong, and even early mortality can lead to a new life that saves the day.

Black spruce is the hero. Its list of hardships is now a checklist of preferred traits for sustainable mass timber construction:

  1. The short growing season faced by black spruce produces tight growth rings, which is ideal for creating high-strength wood fibre. 
  2. The tree has small downward-sloping branches, designed to survive heavy snow loads. Small branches leave only small knots in the milled lumber, which allows it to retain superior strength characteristics. 
  3. It often grows in dense stands and is exceptionally straight. As a result, black spruce boards have straight, uniform grain, giving them exceptional stiffness and stability.
  4. Black spruce is a short-lived tree which begins to decline in health around age 80. They also stop taking up CO2 and start to release it as they age further. Not surprisingly, this coincides closely with the historic frequency of natural wildfires. Harvesting black spruce before they decline helps to reduce CO2 emissions.

In contrast, large western conifer species like Douglas Fir continue to absorb CO2 throughout their lives and can act as growing carbon sinks for 300 years or more. As a climate-change mitigation strategy, the science makes a compelling case for protecting long-living trees, allowing them to remain in forests to take up and store carbon. At the same time, using black spruce for mass timber is environmentally responsible, as it locks the carbon of end-of-life trees into durable products and reduces the occurrence and intensity of wildfires.

To make mass timber, black spruce requires a passionate and innovative ally. That ally is Nordic’s parent company, Chantiers Chibougamau, which has worked in Quebec’s northern forests since 1961, turning black spruce into lumber and I-joists. In 2000, after years of development and testing, the company introduced the Enviro-Lam process, a method for making large-section glulams out of small-diameter logs. It was a breakthrough that allowed previously unutilized wood fibre to find a high-value use. In 2010, Nordic Structures built North America’s first Cross Laminated Timber (CLT) line and kick-started the continent’s mass timber movement, with black spruce as its undisputed champion.

Understanding and working with nature provides the best innovations and outcomes. When we adapt our approach to fit the resource, both nature and people can thrive.

A section of Nordic Lam+ shows the innovative 30x50mm (1.25”x2”) lamella made possible by the Enviro-Lam process. Also, on display are the impressively tight growth rings that make black spruce such a structural gem.

Michigan State University’s new STEM building is a marvel of visually impactful design and utility, made possible by black spruce.

Roof Deck Solutions

Posted on by Gary Snider

In this article, we look at a critical but often underappreciated part of timber frames – the roof deck.

In modern timber framing, whether with sawn or mass timber, the roof deck is the first layer that is attached above the ceiling beams or rafters.  It’s a big part of what makes timber frames strong and attractive.  We call them decks because they’re more than a ceiling finish; they carry roof loads and resist forces that could distort or damage a building.

Tongue and Groove

The most popular roof deck material that Cornerstone supplies to client projects is “2×6 tongue and groove boards”, in pine or fir.  These boards have a profile that allows them to fit tightly together and span up to 5’ between rafters.

When T&G boards are nailed onto rafters the high friction connection between boards makes the entire roof act as a single unit which can resist lateral forces, such as those created by high winds.  They also provide these great benefits:

  1. Continuous nail base – which means a nail or screw will always find a solid base to attach to. This makes installing the rest of the roof so much easier.
  2. Work stage – during construction, T&G decking supports workers, making their job faster and safer.
  3. Interior finish included – not only strong, but also good-looking, T&G boards provide an interior ceiling finish that goes well with timbers.

Tongue and groove boards come in other thicknesses and profiles as well. 1×6 is a favourite for accent walls where the look of T&G is desired but the strength of 2” material would be excessive.  And double T&G is made in 3” and 4” formats to be used for spans of 6-8’. It’s harder to find and is often a special-order item that may take 3 months or more to produce.

Mass Timber

Modern and minimalist designs, both residential and commercial, have long spans that require roof decking to match. Laminated wood decking answers this need, coming in 8” and 12” widths and lengths up to 60’.  Spans of 10-12’ are typical.

What’s Next

Micro CLT is a fairly new product that is made up of 3 ply’s of laminated wood that run crossways to each other.  The material comes in panels, in a variety of dimensions up to 6’ wide by 15’ long. Thicknesses range from ½” to 2-1/4” so it can be used as a wall, ceiling or structural roof deck.

The cross-lamination makes this material extremely stable and strong, while keeping all the beauty of natural wood.  Micro CLT often comes with a lap or T&G edge profile, allowing them to fit tightly together.  The panel format will enable them to be installed fast!