Jefferson Sawmill Pushes Local Hemlock as Substitute for Southern Yellow Pine

Anyone who’s ever framed a porch or a deck in Maine has probably used pressure-treated lumber from the southern US. It’s affordable and readily available in virtually all building supply stores.

This year, PT southern yellow pine grew scarce and pricey. That created an opportunity for a family-owned sawmill in Jefferson.

NC Hunt is pushing its pressure-treated, locally-grown Eastern Hemlock as a substitute product where rot-resistent dimensional lumber is needed. “Hemlock is grown locally, sawn locally,” said owner Rob Hunt.

For now, the hemlock is an experiment, but Hunt thinks it will grow into a permanent replacement. “I’m going to do it as a replacement commodity, a parallel product” said Hunt, the third-generation of his family to own the sawmill. The company also owns retail lumber stores in Jefferson and Damariscotta.

Hemlock is one of Maine’s “under utilized” wood species. It’s used in beams for timber-framing because of its strength. It’s also used for sign posts and landscape timbers because of its natural rot resistence. Green hemlock is occasionally used in home framing, although it requires approval of a local code officer because it typically does not carry a grade stamp. A lot of hemlock just goes into lower end markets and processed into pulp or biomass chips.

This is a good time to be pushing hemlock for use in framing decks and other construction where moisture is a concern, said Hal Bumby, owner of The Maine Wood Treaters in Mechanic Falls. His company treats both southern yellow pine and hemlock. He’s seen the price for southern yellow pine skyrocket, largely because of Covid-related shutdowns of mills while home construction has boomed.

“We’ve never seen the prices we’ve seen this year,” he said.

Bumby’s company treats most of the PT lumber sold in Maine. The southern yellow pine arrives by rail, milled to dimension and kiln-dried. At The Maine Wood Treaters, it’s loaded into a giant pressure cookers and treated with micronized copper azole (MCA), then distributed to big-box stores and retail lumber yards.

Bumby, who has already shipped several truckloads of treated hemlock to NC Hunt, is very bullish on the hemlock venture.

“Here’s my guess: he’ll be able to develop a long-term product. There’s already one for landscape timbers,” he said.

NC Hunt in Jefferson Photo courtesy LCTV

“It’s not like the first time we’ve done eastern hemlock. We’ve had a market for landscape timbers for thirty years and a market for sign posts,” he said. “But what [Rob] is doing, what’s unique this time, is his interest is to go into the retail part of the business.”

The the price of southern yellow is cyclical, said Bumby. “There are times of the year when southern pine is less expensive than hemlock. But for most of the year it’s more expensive.”

That’s what Rob Hunt is counting on.

“Right now, the price is abnormal,” said Hunt. “It’s created an opportunity for us to experiment and see if we can gain a foothold.”

Treated hemlock will last just as long (50 years) as treated southern yellow pine, though the treatments are different, says Bumby. Southern yellow pine’s exterior cell structure (the sapwood) is very porous, making it easy to treat, said Bumby. Because hemlock is more difficult to treat, it is “incised” or perforated with small indentations, which both allow deeper penetration of the copper azole and help reduce cracking as the wood swells and shrinks with humidity.