Heritage Restoration, Inc.

Choosing The Right Wood

One of the most fascinating, dynamic, misunderstood and misused building materials is wood.  Wood works in compression(push) and tension(pull).  Wood can be manipulated, cut, milled, shaped, fastened, sanded and finished.  Yet all woods are not the same.  There are over a thousand North American trees, and around one hundred thousand trees worldwide.  When you a pick out a wood you can see ten or a few hundred depending on the supplier.  There are softwoods and hardwoods, a term that gets misused quite a bit.  “Hardwood” floors are not actually all hardwoods, like pine.  How do they differ?  How to they behave? What is the best wood for price?  How about decay resistance, look, finish ability?  Well, the short answer is a long one.

 

I love old buildings for a lot reasons.  I appreciate longevity.  Old buildings still exist by good care, or great craftsmanship, or good materials, or dumb luck or some by combination.  I respect each reason, becoming fascinated by something existing or just a great detail.  And I learn a lot too from what is still there.  With all existing buildings, I can see what worked and what didn’t.  And above all, bad craftsmanship and bad materials don’t even make it to antiquity.

 

I yearn for the day that the American chestnut comes back, which it always seems like a new blight resistant strain is right around the corner.  It was one of the most beautiful, had great decay resistance, grew straight and fast, worked like softwood but wore like a hardwood.  But we have other choices, and in selecting a wood you have to start with the basics.

 

Density

Density affects a wood’s ability to be manipulated and wear.  Pounds per cubic foot measure density, where Balsa is less dense and Ebony more dense.  You would not use Balsa to floor with, since it will wear quickly.  Nor would you want to use Ebony since machining and installing it would just be too much.  Pine, cedar, poplar and spruce are moderately dense and effective to machine and wear.  Poplar is a great interior paint or even a stain grade wood.  Denser woods like oak, cherry, walnut, and hard maple are extremely durable and can finish quite beautifully, yet are harder to machine and sand.  A quick Internet search about “wood density” can help guide you.

 

Decay Resistance

Rotting wood can be delayed by the type and cut, not just chemicals or the finishes you put on it.  Pressure treated wood is pretty much the lowest form of pine, where without chemicals it would rot in about a year.  Pine’s growth is accelerated, where the distance between growth rings is farther than any old growth, changing the density and decay resistance.  With chemicals, pine breaks down not from mildew, lichen or bugs, but by splitting, checking, warping and then just falls apart.  And the chemicals fail eventually too. Common heartwood species with high decay resistance are white oak, red cedar, cypress, chestnut (sniff), and walnut.  Common heartwood species that have low resistance are pine (other than eastern white, longleaf and slash, which is considered moderate), spruce, and poplar.  Wood decay resistance can be found on the web.

 

Quality

Quality is everything.  You want solid vertical grain heartwood.  Heartwood is the center structure of the tree and the sapwood is the outer active food processing part, which is yummy to bugs and organic matter.  Knots are in essence end grain, which brings in moisture in and out.  Knots also suggest the wood is not vertical grain, causing the wood to warp and grain to “lift” from the end grain being exposed.  I personally do not like finger jointed anywhere, especially outside.  It’s purely an aesthetic thing.  Functionally it’s OK.  The glue can be a good exterior grade, but each piece of wood moves independently and the finger joints are eventually revealed, causing a bad look and a weak joint.

 

Materials, especially wood, can be a cheapest cost to a job.  So invest in quality materials and perhaps someone a few generations from now can appreciate the work you left behind.  The next column will be about finishes that preserve and protect.

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