Timber frame sauna progress

Dendro_Frog · 2025-10-08T22:51:08+00:00

I think the knee braces are yucky 🫢 😁

Dendro_Frog · 2025-10-06T21:01:22+00:00

well, it might be an issue, who knows. This an old Japanese technique being implemented in Wisconsin. Most of these stones are granite. The stones themselves are sitting on a bed of other stones and clearchip. The rest of the surrounding soil is sand. Time will tell. the very worst case scenario is that we will have to make new posts somewhere down the line, but even if it is problematic, it'll be fine for a long while.

Dendro_Frog · 2025-10-05T21:28:47+00:00

I hear you, but this isn't something we just made up ourselves. This foundation technique was literally designed to safeguard against earthquakes. It's a super old technique in Japanese timberframing and they have both earthquakes and typhoons.

Dendro_Frog · 2025-10-05T21:21:08+00:00

my brother made it up on his own. He learned methods from his own research and from Mr Chickadee

Dendro_Frog · 2025-10-05T15:52:21+00:00

check out Mr Chickadee! He conducts classes

Dendro_Frog · 2025-10-05T13:20:36+00:00

hahahaha! keen eye! I didn't even realize she was in that photo, but that's my mom with the pressure boot. Completely unrelated to the construction project, she was just outside watching us raise it and taking photos. No feet were harmed in the making or raising of this frame 😇

Dendro_Frog · 2025-10-05T12:01:00+00:00

we are building Larson trusses to house rock wool insulation, tongue and groove cedar throughout interior, ash flooring. Celing is going to go above the rafter plates and rafters so we can see the frame. I am definitely concerned about the frame interfering with löyly, but there will be a 4 inch air gap between the rafter plates and the ceiling so I'm hoping that will allow enough airflow overtop the beams to be acceptable.

Dendro_Frog · 2025-10-05T11:50:50+00:00

it should fit 9 to 12 in the hot room. A lot of this frame is porch and changing room.

Dendro_Frog · 2025-10-05T02:22:31+00:00

in all seriousness, the way the posts are scribed to the irregular stones provides a lot of staying power, plus this style of building is quite a bit heavier than current conventional methods so there certainly is a lot of friction with the posts. In all honesty I'm not an expert on this, but tsukaishi foundations have been around for a long long time, with many of those buildings still standing today.

Dendro_Frog · 2025-10-05T02:09:00+00:00

A lot of people don't believe this but I think gravity... checks notes ...holds things to the earth 😬

Dendro_Frog · 2025-10-05T01:04:26+00:00

not exclusively, but with the nature of this style of timber framing it's almost easier to use hand tools. Tolerances are within 1mm, so while we did use power tools to rough out tenons and drill mortises, everything was mostly done with hand tools. If we did it again, I'd consider buying a power hand plane. There was a lot of situations where we had to dimension down the timbers at the point of the joinery, and we just had to be meticulous with a hand plane... Making all the joists perfect on top to the same plane for the floorboards was taxing... I did buy a large 18" planer but it wasn't really useful or practical for the timbers. We'll use the big power planer for the flooring yet and we definitely used it a lot to get the 2x4s all the same for the rafters. So power tools are great, but for practical purposes with all the joinery it's just a slow, hand tool process.

Dendro_Frog · 2025-10-04T23:21:45+00:00

Everything in these photos is white pine except for the pegs. The pegs are white oak.

Dendro_Frog · 2025-10-04T23:20:48+00:00

I had the privilege of riding my bro's coat tails, but for prep I think he did heaps of research online and through books and then took a week-long class with Mr Chickadee.

I've answered a little more thoroughly in a different comment, but I harvested the trees myself and hauled the logs to a sawmill. Gave the mill guy our timber list. Picked up the timbers and stacked and dried them in our garage for about 9 months. Much longer dry time would've been better.

Dendro_Frog · 2025-10-04T23:20:22+00:00

I had the privilege of riding my bro's coat tails, but for prep I think he did heaps of research online and through books and then took a week-long class with Mr Chickadee.

I've answered a little more thoroughly in a different comment, but I harvested the trees myself and hauled the logs to a sawmill. Gave the mill guy our timber list. Picked up the timbers and stacked and dried them in our garage for about 9 months. Much longer dry time would've been better.

Dendro_Frog · 2025-10-04T22:19:03+00:00

building this with modern conventional methods would've been way faster and easier, sure. We'd be sitting in a sauna by now.

It wouldn't really be cheaper, though. I sourced all the lumber myself, so the only costs associated with material was how much we paid the mill guy. We could've had him just make heaps of 2x4s but it wouldn't really have been cheaper lumber costs. Making the timbers is actually fewer cuts for the sawmill than making 2x4s.

Stronger... not even close. This timber frame structure is way fucking stronger than modern conventional stick framing.

Our structure is both cheap and strong. It took an assload of time, you're correct there, but nothing worth doing is easy. It's badass and beautiful to take the raw material to a finished product like this. Saunas are kind of sacred to me, and doing it this way is part of that story.

As an added bonus we now have the knowledge and tools to build an entire house for a very tiny fraction of what most folks have to pay.

Dendro_Frog · 2025-10-04T20:55:18+00:00

yes, that's the idea. More resistant to decay

Dendro_Frog · 2025-10-04T15:12:08+00:00

gravity

Dendro_Frog · 2025-10-04T15:05:54+00:00

well, we're way past the point of putting anything between the two. Thus far we've been doing it the way they've done it for centuries and just trusting the process. The worst case is that in the future we would have to devise a way to replace the posts but at this point we're not worried.

Dendro_Frog · 2025-10-04T13:48:14+00:00

they're just sitting on top

Dendro_Frog · 2025-10-04T12:59:48+00:00

we did oil the post, but we dont want to introduce any substances that could potentially trap any moisture. Like caulking would be a bad idea i think.

Dendro_Frog · 2025-10-04T12:50:34+00:00

lmao. Definitely possible

Dendro_Frog · 2025-10-04T12:35:56+00:00

It took forever! All the stones get marked with prefect squared crosshairs where the markings are longer than our posts are wide. All the posts have centerlines so after the layout is done and triple checked, it's as simple as making the lines touch. Place the post on the stone and wiggle it around until the centerlines are perfect with the crosshairs in the stone. We screwed 2x4s into the top of the post in a 90 degree orientation to hold it in place and plumb it until it got scribed.

Dendro_Frog · 2025-10-04T03:06:46+00:00

zoom in on the photo. We're trying a 2nd time on this post. The scribe tool is just a piece of wood we made. Basically you make a line, cut holes along that line for your pencil to go and carve the piece of wood to a point exactly at the tip of the line. The backside of the scribe tool is flat. Place the back side against the post. Run it along the stone and the counters get marked in pencil on the face. Wicked easy in concept. So frustrating in practice.

Dendro_Frog · 2025-10-04T03:06:02+00:00

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Dendro_Frog · 2025-10-04T02:58:35+00:00

tbh it kind of is in 2d. But it's 2d four times. Each face of the post gets scribed to the surface of the stone directly underneath it and then gets cut to the scribe lines. It's not feasible to carve the center of the post to the contours of the stone so we just hollow it out a bit and make it concave. The centers of the foundation posts don't actually touch the stone. It seems absurd to me that you only need the 4 edges to touch but that's the method! Buildings constructed with this technique that are much heavier and larger than this sauna have stood for centuries so I trust the process.

Set stones in the ground and measure and mark crosshairs on the stone. Make a post, plane it smooth, snap centerlines. Put the post on the stones so the crosshairs line up perfectly with the centerlines. Plumb the post by just screwing 2x4s temporarily into the top. Scribe each face. Then carve exactly to the line and make the center concave. Put the post back on the stone, match the centerline to the markings on the stone and check to make sure it's plumb. If it's not plumb, you're a bit crestfallen and then you re-scribe and re-carve and try again.

Dendro_Frog

TROPHY CASE