And I mean it, says Neal. Wood is such a wonderful material that if it didn’t exist, we’d have to invent it. It’s so universal, so versatile and so important…
JUST for a moment look at all the uses for this amazing material. Briskly rub two boy scouts together and it can keep you warm and toasty; wood is considered humankind’s very first source of energy. Today, according to the UN, FAO, it’s still the most important single source of renewable energy providing about 6% of the global total primary energy supply.
More than two billion people depend on wood energy for cooking and/or heating, particularly households in developing countries. It regenerates and is beyond eco-friendly, sucking up all that nasty CO2. If we all looked around our homes and imagined the wood magically gone, there’d be nothing there but a load of gaping holes and a heap of bricky/tiley rubble in the middle.
So what’s the smart thing about wood? Light and strong, you can drill, saw, plane, shape, sand and bend it. And the grain is beautiful, coming in so many variations. It’s like every year the trunk gains an extra ring of straws, small straws in summer and tiny straws in winter, progressing outward, ring-on-ring.
Imagine this like a load of different coloured rubber glove fingers, built up, as one is pulled on over the previous one. Then imagine the patterns revealed as you cut through at different angles. Sigh! No Rodney, you have to take your finger out first!
However you cut it, and the pun is entirely intended, wood will always remain just wood. Its hardness is dependent on species as according to Messrs Janka and Brinell. It doesn’t matter whether flooring or framing, no sort of magic sealer or finish is going to make it any harder than God intended, even with diamond hard aluminium oxide finishes.
There are of course differences between hardwoods and softwoods – some quite subtle in actual usage. So what’s the difference? Basically, hardwoods have comparatively larger flat leaves and softwoods have needles or little scales. Or another way, hardwoods have flowers and ‘fruit’, mostly quite small, whereas softwoods have cones hence being ‘coniferous‘.
Balsa is a hardwood, but a good sneeze will dent it. Ancient softwoods such as Baltic pines and spruces, grow so slowly up near the Arctic circle, the annular rings are so closely packed you can count 30 rings to an inch, However, a piece of New Zealand Pinus Radiata will only scrape three rings to the inch. This is all down to warmth and the length of the growing season, or lack of it.
There is a differing internal structure between softwoods and hardwoods, of tracheids or vessels, respectively. This is why you can pump preservatives into soft wood but not successfully into hardwoods.
More years ago than I care to be reminded of, I was at an NZ Forest Products facility. The day’s operation was the production of pine logs to make some serious marine piles. A clamping pressure ring was cinched around the base of the log butt, the pump switched on pumping tanalith (chromated copper arsenate) until it exuded from the cut branch scars and oozed out the log’s far end. Very impressive. And so we get to flooring…
Yes, there are some very clever vinyls, LVTs and even tiles, all looking to emulate wood, but it just isn’t the same, just not the real thing. But make no mistake wood essentially remains a dynamic living entity despite being cut down, and it never really quite ‘dies’.
Being hygroscopic, wood absorbs and releases moisture responding to the ambient conditions, expanding and contracting to the surrounding RH. If you doubt this, hold a sheet of copier paper over a boiling kettle. Watch it ripple and buckle as the wood fibres distort in absorbing moisture
Remember Granny’s backdoor? It rattled in its frame in summer, but you had to shoulder charge it shut it in winter. QED.
In flooring terms it is this sensitivity to moisture that mandates the subfloor MUST be adequately dry, otherwise all that happens is that the kiln dried timber promptly sucks up the available excess moisture and cups, springs or buckles, as Freddie the Flooring Contractor is starting to learn. (Gosh, did someone mention a moisture meter?)
Clever manufacturers specify expansion gaps. These are critical even on a glued-down floor, but especially so on a floating floor installation. The flooring contractor ignores this at his peril! Because of the makeup of engineered flooring, also known as multilayer flooring, this designs out much of the movement – but certainly not all of it
I’ve seen floors installed with no expansion, that have pushed outdoor frames and stud walls.
If this ability to expand is completely limited or restricted, the floor can bow up in the middle to an astonishing 400mm or so.
There was a tale that in the old days of quarrying, before the advent of air-driven rock drills and gelignite, that long slim oak wedges were made, and completely dried out by the fire. Then Ye Olde Young Rodney was dispatched off to the edge of the quarry face to hammer in these wedges every few inches into cracks.
He subsequently returned with buckets of water to drench the wedges. They expanded, and hey presto, the rock face split away. Apocryphal perhaps, but I can believe it.
