heat treated wood (pavilion @ hanover exp)

the finnish pavilion, designed by SARC, features a heat-treated wood exterior, made by Stellac.

looking for more information on the application/method, specifically if anyone has used it or similar...

it reminded me of heated + tar covered wood exteriors in staves...
i'm loving the color variation as well...


office building:

Apr 5, 07 2:29 am
Carl Douglas (agfa8x)

Is the wood blackened by scorching or is that just the tar?

Apr 5, 07 2:40 am


Apr 5, 07 2:53 am

i think it's tar that gives it the coloring... but i'm not sure of the process

Apr 5, 07 2:57 am

It's just scorching. I'm working at SARC, but I came here after this project. The process is used to make the wood resistant to moisture - a non-chemical approach. There is the temporary cafe-building in Helsinki (2003-2004, or something) "hiili" that also used this method in the whole outer surface. If you have some specific questions, I can try to answer.

Apr 5, 07 3:49 am
Carl Douglas (agfa8x)

It's really beautiful, Helsinki. So do they blast the wood with a blowtorch, or do they use some kind of kiln? And there's no other treatment needed?

Apr 5, 07 5:09 am

a room sized oven is used.

the wood is being held in a high temperature for hours and the molecular structure of chages - like in controlled burning - it becomes waterresistant and a bit brittle.

The exact degree of change can be set.

But no chemicals involved. or other treatments necessary.

Apr 5, 07 8:12 am

this project also uses tar. nice box.
in the winter the roof got a bit bent by the snow I guess, but it was a temporary structure.

Apr 5, 07 8:19 am

I heart the Fins.

Apr 5, 07 8:35 am

I heart the Fins.

Apr 5, 07 8:35 am

Thanks. we like to be hearted.

Apr 5, 07 8:38 am

The Finnish Pavilion in Sevilla is one the most beautiful projects I have ever seen.

Apr 5, 07 8:51 am

Th epavilions are taken here pretty seriously. Aalto has done few (focus on the interior, though) and the designs are chosen by anonymous open competitions. The Sevilla designers were about 21-25 when they did it - all still students. It's a nice tradition.

Apr 5, 07 9:00 am

you guys hiring? ;)

thanks for the info. i'll definitely be looking further into it. when i worked in germany, i did a lot of projects that had no insulation, and am interested in continuing down that track here in the u.s.

i really liked the cafe... shame about the snow

i always thought they should have done this to the wood on BCJ's ballard library..

Apr 5, 07 10:44 am

I scorch the wood on some of the furniture I make. It's an interesting way to bring out the grain of the wood, and gives a look that not everybody's seen before. After that, stain the wood a nice dark colour and it's very subtle. (I know this is a small-scale DIY version, but that's how I roll). I use a propane torch.

Apr 5, 07 12:54 pm
Carl Douglas (agfa8x)

Thanks, Helsinki.

Apr 5, 07 3:35 pm

helsinki, do you have to use a would thats rot resistent, like redwood? Or can other woods be used??

Apr 5, 07 3:42 pm


Apr 5, 07 9:42 pm

I think (not sure) any wood can be used - the wood in the pavilion is pine.

Apr 6, 07 7:27 am

In the US, the process is called retification, but it has other names globally. Its shown to improve the weather resistance but reduces wood's strength in bending. Google these:

Durability of heat-treated wood, research paper by D. P. Kamden et al

Wettability changes and mass loss during heat treatment of wood, research paper by Mohammed Hakkou et al

Heat Treatment of Wood in France – State of the Art, information paper by Michel Vernois

There is a related process called viscoelastic thermal compression, which you can read about in these papers:

Densified Radiata Pine for Structural Composites, research paper by Frederick A. Kamke, Oregon State University

VTC Wood, information paper by Fred Kamke

Sorry I was too lazy to find the links for you, but some of these you may need a subscription to a research database.

Apr 6, 07 5:20 pm

jackalope, you must be an expert in Deadwood...sly smile.

Apr 6, 07 5:33 pm

no links necc. i'll check that out. much appreciated

Apr 6, 07 8:19 pm

snooks, nope, not an expert, but I can fake it pretty good. :)

Apr 7, 07 7:20 pm

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