Comment by jimmy1 | Hacker News Reader

Comment by jimmy1 | Hacker News Reader

I CTRL+F'd for "deforestation" in the article, thinking that anyone in their right mind talking about using that much more timber would at least mention it, and was surprised not to even see it mentioned.

> When a mature tree is cut down, a new one can be planted to replace it,

Again, expert carpenters could correct me if I am wrong, but the higher quality desired wood is called "old wood" some of which is over one hundred years old. You can't just snap your fingers, plant a field of trees and expect that to be ready in time to meet a surge of demand. The stuff is already extremely hard to come by -- you ain't gonna find it on the shelf in any big box store.

The vast majority of the stuff used today is "new wood", cultivated to grow as fast as possible, so the wood is not as dense and, as a result, weaker and more susceptible to decay and instability. Not exactly what I would want my skyscraper built out of.

I am assuming the author was considering composites and manufactured wood products as well -- again, these have not been proven to be as structurally sound as old wood over time.

Then the other factor in play here is the increased demand in logging. Logging is one of the most dangerous jobs on the planet. You would technically be requiring more loggers, thus causing more logging deaths.

Not so sure this is such a good idea, but I could be wrong.

I am from Austria, a nation where wood is one of the most important building materials of houses since centuries.

We have more wood than we use in the last years.

Deforestation, the work dangers of logging and responsible logging (e.g. avoiding to log whole areas which leads to erosion and destructive dirt avalanches in mountainous regions; planting and growing with a long term plan) are problems of law and personal responsibility. That beeing said in Austria this was a problem in the 70s, definitly not a problem any more. Owners of wood certainly feel some sort of responsibility for the landscape they own over here.

Although fast grown woods are indeed softer, compound materials are a good alternative and I have seen houses from the early 90s that are still rocking that new technology (like my old skies). More exotic materials like bamboo (technically not a wood but a gras) offer a very good alternative in mechanical terms (also grows quite fast).

It is up to us to build the framework in which wood can be used responsibly, with all side effects considered.

If they are using softwoods likes pine then it is mostly all grown on tree farms industrial style and doesn't take that long to grow. Hardwoods can and sometimes are grown on tree farms but the 60+ year harvest makes it an unattractive investment.

There is no problem making things out of faster farm grown hardwood(and not all hardwoods take a long time to grow either) but due to the fairly easy availability for natural grown hardwood, atleast around me in the US and Canada, you don't see many hardwood farms. While farm grown hardwoods might be a little less dense, it isn't anything that can't be solved by using slightly thicker pieces. And on top of that, farm grown trees are better pruned and maintained, meaning better quality controlled logs with less significant knots and crazy changes in wood grain. You will get far more consistent and reliable beams and boards from farm grown wood, especially at long lengths.

The slower grown old growth trees have slightly better figure due to thinner rings but in any application where you aren't paying a huge premium for looks, it isn't that different, and 99/100 people couldn't tell the difference.

The one object you really do need the really slow grown old shit is for musical instruments where even relatively small increases in wood density can significantly improve the tone of an instrument.

I believe that glue-laminated timbers (which were mentioned in the article) and plywood (which features heavily in housebuilding - at least in Vancouver) can be made from younger trees.

It is plausible that foresters would struggle to meet a surge in demand, but growth in wooden house building could be slow - particularly in resistant markets (like the UK). I also remember reading that young trees remove more CO2 from the atmosphere than mature trees, so a surge in logging and replanting (and and expansion of forestry efforts to keep up with demand) could have a benefit in fighting global warming.

That's true that newer woods are softer, but often for structural applications special types of engineering wood products are produced from newer woods which are very strong. One example that comes to my mind is structural ply, it's really strong stuff and practically always made from soft timber.

I found a reference here (https://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr190/chapter_...) that discusses the mechanical properties of some of these fabricated structural wood products. Everything seems to be in comparison to just plain hardwood, but nothing seems to point to that it meets or exceeds the strength of hardwood. I am not convinced that any amount of glue, plastics, and pressing together other hardwoods (presumably, young woods as well) will stand up against good old fashioned old wood timber, which I simply don't think we have enough of to start building tall buildings with. If that's the case I'd rather be on the top floor of a steel building.

They’re only going to design the building to be strong enough to withstand the loads it needs to bear, plus a standard safety factor. If they use a stronger material, they’ll use less of it so that the resulting strength is the same.

I can understand being skeptical of decay, fire resistance, sound deafening, or other factors like that, but being worried about the strength makes no sense.

Making concrete is one of the larger CO2 contributors on the planet. Trees ARE captured carbon dioxide. Cross laminate timber is very strong. We need to give value and purpose to these materials again by choosing to live and work in them.

I don't think that deforestation is too much of a concern for the quantities of wood needed to construct buildings that will last 40+ years. Building construction is a fairly small user of wood compared to fuel and paper products (These are roughly 75% of wood usage).

That's also only one tiny aspect to logging. Loss of biodiversity, soil erosion, micro-climatic shifts, the impact on streams, all can be devastating in isolation, let alone together. Saying that you can plant new trees to replace old ones is a 1950s era lame-ass response to the issue, it is not suitable, let alone intellectually serious, as a "proposed solution" in 2019.

This is certainly a concern when logging old growth forests that have never been logged before, but I'm not sure it is such a concern with managed forests. I am pretty comfortable with the idea of increasing the area allotted to managed forests in the uk, particularly if it is allowing for a reduction in CO2 emmissions from homebuilding.

I also suspect that the alternative for areas that are/could become managed forests is not for them to be left alone and undeveloped.

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