Dining Room Renovation

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Welcome back folks, it’s been a while. A lot has happened over the past few months, and despite my best efforts it’s been hard to find the time to sit down and write. There’s so much I’d like to share here on the blog but between commissions, teaching, and the house renovation, time has become increasingly scarce. The new year looks to be no different. I’ve got a pretty full teaching schedule all year, and while I’d like to set aside time to create some new work in the shop, the big thing looming over everything is still the house work. This year the goal is to remodel the kitchen, tear down a rotting chunk of the house, and expand the shop.

But for now let me share a bit of the work that took place since the last post, and for starters here are some before pictures. The two rooms that I’ll cover are a storage room and the dining room.

Heres the dining room when we bought the house, looking towards the storage room. The two doors in the center were locked in place as a result of the building sagging on the right. The rightmost door stile is even bowing outward as a result of the pressure.

Turning to the right are the old glass doors which look out over the north side of the house.

And the view from the outside.

Aside from the structural work necessary to straighten out the building (which I’ve covered a bit of in previous posts), the overall goal for these rooms was to replace the old tatami mats with a new wood floor, and replace the leaky glass doors with a half wall and windows. Plus a lot of other details necessary to make that stuff happen.

A couple of the not so minor details involved replacing two massive floor joists (ashi-gatame 足固め). Here is one of the big keyaki posts in the building with exposed mortise after the old floor joist was removed. Rather than remove any more material from the existing post, I opted to match the end of the new floor joist to fit the old mortise.

When you’re doing renovation work the scope of the work can change quickly. One minute your doing demolition the next your cutting and fitting patches to cover over loose knots in a new floor joist.

Below you can see the first floor joist installed. Still exposed is the mortise for the adjoining floor joist…

….which after cutting to fit looked something like this.

One of the trickiest aspects to renovation work is figuring out how to get new members in place. In this case I had to figure out how to squeeze the new floor joists into place without being able to spread the post apart. One great method, that I learned at Somakosha, is to use floating tenons. With an integral tenon the posts have to be spread a considerable amount to get the beam in, but with a floating tenon the beam can be slid into place with minimal movement of the posts, and then the floating tenon can be inserted either through the mortise or through a channel cut into the beam itself. In this case I fit the tenons through the mortise. Keys (shachi-sen) on either side of the tenon pull the beam tight to the post, while a peg locks the tenon to the post.

The hole for the peg in the tenon is slightly offset from the mating hole in the post, and the slots for the keys are tapered creating a strong draw bore effect when driving everything together. Overall this form of joinery makes for a really strong connection.

All of the posts required new stones since I did away with the sill beam which had rotted out. Most required a bit of adjustment with a grinder and cold chisel to chip away at high spots making them flatter and a better fit for the situation.

With the floor joists in I could start work on the rest of the floor structure, starting with a mid-span floor joist called an oobiki (大引き). Oobiki are typically tied into the surround floor joist and occasionally a post, and they are typically smaller in cross section than the main floor joists.

Once the oobiki were in, small floor joist called neda (根太) are installed spanning across the whole structure. Neda are really small by Western floor standards at 45mm wide x 55-60mm tall, but they are spaced fairly close together making them strong enough, especially once the flooring is installed.

With the floor stucture complete , I could start building the new wall where the old aluminum/glass doors used to be.

First I installed the nuki, cross braces which pass through the posts, follow by a long window sill.

Before closing off the wall completely I decided it was time to lay down the finished floor while we still had good access to pass boards into the house through the open wall. The floorboards are clear Japanese sugi tongue and groove, spanning full length from wall to wall, making for a pretty clean finished floor.

With the floor done I started to finish closing up the wall, and first task was to secure the nuki with wedges.

Next comes the bamboo lattice work (take-komai 竹小舞). The thin bamboo sticks in the image below are “structural” in the sense that they are tied directly to the structure and rest in shallow mortises. They also get screwed to the nuki where they overlap.

From there it’s a matter of cutting lots of bamboo sticks to length and tying them to the “structural” bamboo framework, working one side at a time. Here I’m finishing up the interior side with the horizontal bamboo.

And below is the finished lattice after installing the vertical pieces on the exterior side. I really love seeing the wall in this state. There’s something so interesting about seeing the different layers of structure.

At least a month and a half or more before all this work, a friend and I mixed up some clay from our land as well as some rice straw and let everything ferment, which has the effect of softening the straw and making the whole mix much more workable. Getting the right blend of clay/straw/sand has been an ongoing learning experience, and perhaps I’ll share more on that someday. In any case I’m far from an expert when it comes to earthen plaster, but I’m pretty happy with how this batch turned out.

It went on the walls nice and smooth, and was much easier to use than previous batches. I love the chocolately color when the mud is fresh, it dries much lighter, yet still retains a nice warm brown tone.

Heres a look at the inside of the final wall section before finishing off the exterior. You can see how the mud squeezes through the bamboo lattice work effectively locking the whole thing together.

Once the walls were mudded it was time to make windows and officially close the sturcture for the first time in 9 months! Crazy to think we lived with plastic and other temporary walls for so long.

Since taking these pictures the rough coat of mud has dried on the walls and I’ve started to apply a middle coat to further finish things off. I also built and installed the windows, so the new space is feeling much more finished these days. I hope to have some better photos of the completed space to share once things are a bit further along.

Thanks for reading.