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<body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif; ">On Fri, 13 Nov 2015 07:48:47 -0500, Aaron Stavert <aaron@openpractice.ca> wrote:<br><font class="Apple-style-span" face="Consolas,monospace"></font><blockquote style="margin: 0 0 0.80ex; border-left: #0000FF 2px solid; padding-left: 1ex"><div><div><font class="Apple-style-span" face="Consolas,monospace">Here is a link to a company here in Canada. If you click on the technology section there are some great resources and explanations there.</font></div><div><font class="Apple-style-span" face="Consolas,monospace"><div><a href="http://www.thermalwoodcanada.com/">http://www.thermalwoodcanada.com/</a></div><div><font class="Apple-style-span" face="Consolas,monospace"><br></font></div></font></div></div></blockquote><div id="M2Signature"><div><br></div><div>Thanks for the above link Aaron. It (in particular, the pdf from the Finnish assoc) has been the most useful so far in my education about this new-to-me process. </div><div><br></div><div>I suspect that Sacie had already known more about the 21st C "heat treated wood" process than I when she posted her query to this list.</div><div><br></div><div>My initial reaction after reading the Finnish pdf is one of chuckling and saying to myself </div><div><br></div><div>"Yup. 'Heat-treated" wood *is* "polishing a turd". The Finnish association literature even admits that the stuff stinks".</div><div><br></div><div>... but that criticism is mostly tongue in cheek.</div><div><br></div><div>So far I've not seen any embodied-energy numbers for heat treated wood other than a generalised claim that the energy required for the process is about 25% more than fhat for conventional kiln drying.</div><div><br></div><div>Literature from another Euro site claimed that the service life of heat-treated wood exposed to weather was in the 40-60 year range.</div><div><br></div><div>So from a Green perspective one should look at whether the not-insigificantly higher embodied-energy cost of heat-treated wood is worth the increase in service life expectancy over naturally decay-resistant lumber species and my initial reaction is "No" . Perhaps further education may change that initial opinion.</div><div><br></div><div>I suppose my attitude towards the product is similar to that for pressure-treated wood . Both processes treat lumber species that don't do particularly well in outdoor service conditions and that may be viewed by some (mostly those in the business of selling trees for lumber) as being a Good Thing. (Again, hat "polishing a turd" thing). </div><div><br></div><div>In the case of pressure-treated (PT) lumber it gives the users a false sense of security because the reality is that the treatment chemicals only penetrate mere millimetres depth from the surface and wood being what it is, prone to checking and splitting when subjected to repeated wetting & drying outdoors, exposes the untreated core to entry by the microbes and insects that can still feast on the untreated innards.</div><div><br></div><div>In the case of heat-treated (HT) wood while some of the cosmetic durability properties of the wood seem to be improved, it's bending strength is weakened and any natural decay resistance is lost. Cabinetmakers who work with handtools only will often describe kiln-dried lumber as being "kill" dried. The wood is "dead"... a hollow, lifeless shell of it's former self when compared to lumber that has been air-dried to the same moisture content.</div><div><br></div><div>Heat treatment, due to the higher temps involved, appears to not only "kill" the wood, it turns it into a FrankensteinWood in a manner of speaking . </div><div><br></div><div>But enough of that for now. I've got more important things to do right now... like take my mutt for a run in the woods.</div><div>-- </div><div>=== * ===<br>Rob Tom . . . T60BOM<br>Kanata, Ontario, Canada<br><br>A r c h i L o g i c at Y a h o o dot C A<br>(manually winnow the chaff from my edress if you hit "reply")</div></div></body></html>