Shou Sugi Ban used on a cabin exterior

[ahuntington]

I'm brand new to the forum and am at the start of a very long journey. I'm going to be buying around 100 acres in the southern Missouri Ozarks next year and am planning on using ERC to build a log home. I recently came across Shou Sugi Ban for finishing floorboards, boards for the roof, etc. 

I'm curious how it would work for the exterior of cabin walls? Also, does anyone know if the drying requirements would be the same? If I were to do it to green wood that I just milled, would it create a lot of twisting or warping, etc? FYI, I'm looking at milling the cedar into 8x8 or 8x10 for the logs.

Thanks in advance!

[Lasershark]

Based on my experience, you can use most wood for Shou Sugi Ban technique, but you want your wood very dry when performing the torch-burning or the wood won't char. Cedar does dry quickly when cut to 4/4" 

[ahuntington]

Thanks Lasershark! How long would ERC take to dry if it were bigger? For the logs I'm thinking of doing 8"x8". Everything I've read says ERC dries really quickly, but I also know that humidity is quite high in the Ozarks. Would you recommend just air drying it? Using a solar kiln? And I assume I'd want to dry the logs prior to milling so that I don't have to worry about twisting as it dries.

[Lasershark]

Whatever drying space you have access to is most appropriate. I think indoors is best, so I use an insulated drying shed with a dehumidifier and a little heater. 8x8's will take a while to dry, I'm sure there's a formula around for cant size vs dry time.

[Don P]

Fell and mill quickly, dry as long as possible, and all depending on finish desired and wood movement, remill. Any form of accelerated drying would have to be done carefully with large timbers to minimize checking. Large timbers often want to check heavily under pretty mild conditions. ERC should be about as forgiving as any.
Finding enough 8x8's in ERC will be a job, I'd stay flexible on dimension till you've milled some logs and see what they give up. ERC is relatively dry growing, seasons rapidly and moves little in the process.

[nativewolf]

Our experience with charring wood is that ERC is probably the best alternative to the juniper that they use in Japan.  The wood needs to really char, watch many videos on the actual manufacture in Japan.  It is burnt at a high high temp for about a min with very dry lumber.  Creates deep char almost 1/8" - 1/4" deep.  I expect that a building inspector might be confused by burnt walls.  Also I have no idea how you'd keep that from being your interior wall choice as well.  Mostly I think you'll find it difficult, not impossible, to successfully burn big timbers and keep the burn to 3 sides.  I agree with Don that you might have a tough time getting a house worth of ERC in 8" timbers that don't have cavities, etc.  

We'll do some more experiments here with yellow poplar but will have to get a kiln capacity to dry to a very low MC, might still have to help it out a bit.  

You also need a good water source to put out fires.  You'll need several sacrifice timbers to play with the right amount of fire.  You're going to need to cut them to see how deep you got the burn and you only get 1 chance/beam. 

[Don P]

I know nothing but could you not rack them up as a mat and walk on them with a torch, burning just the one face?

@nativewolf, you're trying  this with poplar? If so I'd like to hear how it works.

[nativewolf]

We could not get enough char with a torch on poplar, web users do t appreciate just how deep these juniper siding boards char after only a min in the furnace that they use.  The techniques is non trivial in my opinion and highly tuned to siding in the one species.  So, I don't see the weed/roof torch actually working.  

They basically create a box chimney and set it on fire to create a 12' tall chimney.  It really cooks!  

Maybe you could do the same with erc timbers and light them with fuel and let them go a bit but knocking the chimney down with 8x8 is different than 1x8.  The time to actually torch the face would be lengthy and expensive.  

[Don P]

Hmm, siding is one thing, these are structural members as well, I dunno how good an idea this is.

[ahuntington]

I appreciate all the feedback. I'll experiment with it when the time comes, but it's looking like that may not really be a viable option the more I learn about it. 

I had seen the chimney style burn, but I also saw some people using a propane burner, which I was thinking of doing on just the exterior side. I can see though that it may be a bit too much. I'll experiment with it and follow up on here with you all, but for now I'm not really holding my breath.