First Look: Shou Sugi Ban

Shou sugi ban, or yakisugi, is an old Japanese technique for treating wood to make it weather-, insect-, rot-, and fire-resistant. It was apparently independently developed in Scandinavia, as well, for the same purposes.

The technique consists of charring the outside layer of wood that is to be exposed to the aforementioned dangers. The charred material can be left on, or it can be scrubbed off. I am scrubbing it off for my project, to make the wood cleaner to handle and to bring out the beautiful grain.

I did my first few pieces--the roof trim pieces--today, and am super pleased with the results!


 The Japanese word sugi refers to a type of tree, Cryptomeria japonica, which belongs to the cypress family and has been the dominant timber species in Japan for hundreds of years. Western red cedar, which is also in the cypress family (not a true cedar), is the North American equivalent to sugi. I'm using 1x Western red cedar for my fascia and verge rafters--the trim pieces that go around the edge of the roof and hide the rafters from the outside view--and will use cedar for part of my siding, too. All will receive the shou sugi ban treatment.

Traditionally, the charring happened over a fire. Today, most people use a propane torch.

Propane tank and weed burner

So today, Dad and I went over to my Uncle Chuck's place to borrow his propane-fired weed burner so I could get started on the roof trim pieces. Chuck handed us the burner and explained how to use it--apparently it can be a bit touchy and you have to remember to do this-or-that when you turn on the gas, or something. Unfortunately, the very next thing he did was to beckon us over to his garage to show us... wait for it... the shiny new Corvette that we had no idea he'd bought! Damn, that's a good looking car! ...Which effectively blew all his instructions about the faulty valve or whatever right clean out of our heads.

Oh well. I figured it out.

So here's what I did this evening:

Step 1: Burn

Step 1: Put on gloves, wear closed-toed shoes, and torch the daylights out of one side of the wood. I turned the burner up 'til it was absolutely blasting flames and charred the wood until it showed a crackly, alligator-skin texture. I charred one edge, too, since one edge will be visible on these trim pieces, and compared to the shou sugi ban wood, the unblackened cedar stands out brightly.


 I held a wet rag and patted out any fires that started on the wood. This usually happened along the edges. If you let it burn on its own, the burn will go too deep.

Result after initial torching

Step 2: Wet

Step 2: Wet the charred surface with water. You don't want to raise up a bunch of nasty black dust when you scrub the charred stuff off.

Do yourself a favor and hook up a hose--don't use a watering can! I only had a few pieces today and I thought it would be too much trouble to drag a hose all the way up to my neighbor's lawn, where I was working. (It's okay, she's my great-aunt, and she doesn't even live there anymore.)

Step 3: Scrub

 Step 3: Scrub the charred material off of the wood. I used a nylon bristle brush and scrubbed with the grain. Lots of black sludge came off, of course. It's a good idea to rinse the brush out occasionally. And duh, wear clothes you can get dirty!

Step 4: Rinse

Step 4: Rinse the black gunk off and check for any spots you missed.

Step 5: Lay the wood on stickers (I used scrap lumber) to elevate them off the ground and let them air-dry.












 There you go!

Before and after scrubbing--photo doesn't capture beautiful satin sheen on the scrubbed wood. Lovely!

There are probably more steps... For example, I will look into whether I want to add a natural oil sealant, like Penofin-brand rosewood oil, which other bloggers have used. Apparently it will increase the lifespan of the treated wood and bring out the colors more. On the other hand, it's almost $50/gallon at the building supply store in town. Yikes!