I have been in the construction supply industry for 30 years and have never hear of Thermory. I would probably stick with Ipe.

Ipe is 50%-70% more expensive than thermo-treated wood. And Thermory is not the cheapest thermo-wood, cos they are making it in Europe and importing to US. And all thermo-treated wood has >25 years life time without any stain. I found another manufacturer in US here (Welldonewood)

There are many thermally modified lumber plants in North America. Search for it online. I live in a small town in Eastern Canada and we have a plant here, Thermowood Canada..

they all produce siding and decking products.

I also have found here thermo-treated siding made of Poplar and Cypress.

Unbelievable, they give 25 years warranty on cypress beveled siding.

You can order a free samples online, and then place online order. Just requested samples to play with it.

Just researching and came across this. What did you decide and how has it worked out?

We worked out that for siding purposes, Poplar will be perfect. There are several manufacturers like Thermory, Westwood, Welldonewood that manufactures similar products. We quoted all of them and gone with the fastest response. The product looks great but you have to be very careful with it as it is pretty brittle. And don't try to paint it. As soon as it was in place, we loved it. But again, have to have experienced contractor.

A sustainable, low environmental impact, long lasting (60-year expected life cycle & 30-year warranty) alternative to both ipe & thermory is Kebony. Goes down easily using Camo screws & looks like a tropical hardwood.

North on Sixty, where can you source Kebony in the USA? Approximate cost per linear foot?

Thermory is a great product and we do carry it. Benchmark series is Ash. Price wise you’re going to be in the same ballpark as Ipe. Personally prefer Ipe. It’s (and I’m sure people are willing to argue about it) the most durable wood available on the market for decking and siding applications.

Try staining again then maybe apply Messmer’s Carib Extreme... worth a shot. So me people swear by Cutex. Strange it’s turning so quickly. I don’t think of Washington State as having that much sun.... September to February? That’s ridiculous.....

Ridiculous is right. Thanks for the tip. I'll try and look into Messmer's Carib Extreme, seems very promising. Was thinking about using Seal It Green Extreme stain since they market it for thermal wood and has some amount of UV protection.

You bet! As many contractors as there are as many opinions you’ll find..... test it on a small inconspicuous place or better if you have a piece of leftover material from install try it on that to see if you like the color and how it works.

Ps read the Messmer’a application directions carefully. Really easy to apply but there is a method to the madness

It's also referred to as "torrefied" wood. I'd use fibrecrete panels before I bothered with the expense of Ipe or the thermally modified woods. One other type is the acetylated wood, which is also rot-proof but stronger and less brittle than untreated. If you're going to spend all that money, I'd go with the acetylated as first choice.

"I'd use fibrecrete panels before I bothered with the expense of Ipe or the thermally modified woods"

For deck boards @Jean Denis

Has anyone heard of Hardi deck in NorthAmerica? i saw it used in Australia but do not know if it has made it to Canada and the US, Hardi Board or concrete panels for the deck application seems like it would be a great product,

I bought Hardie Board and it literally disintegrated when exposed to water. And this was siding. They gave me a small refund, but not enough to cover the expense of addressing all of its issues.

Our company has stopped using IPE and other tropical hardwoods. Although long lasting, if the moisture content is not correct, they warp horribly and have gotten expensive, not to mention the ecological damage harvesting this wood has on ecologically rich forests. We've been using Thermory for a couple of years now and have had great success. It doesn't warp, is quite lightweight, and meets fire code when used on roofs.

@Jean Denis Have you been able to find acetylated wood anywhere? It was briefly available in the USA but then there were some business fallouts and it seems to have disappeared from the American market