Planning a Japanese inspired garden shed

[GRadice]

Thanks, I'm getting excited, too. Frame raising is scheduled for July 29th. I think I need to pick up the pace a little to be ready on time. 

[skatefriday]

When you scribed to the stone, I presume that meant that your posts were all now slightly different lengths.  How do you then reference all the layout on the posts and determine actual lengths so the tops all align properly?

[Ljohnsaw]

See reply 19. Once he's scribed them all to the rocks, he then set them all up and made a reference line on all of them.

[skatefriday]

See reply 19. Once he's scribed them all to the rocks, he then set them all up and made a reference line on all of them.

Thanks!  Post 18 makes reference to shooting a level line.
Any tips on the actual mechanics of doing so?  Just run string around an area near the base and mark off the string?  I'd be concerned about my ability to get the string level enough across such open spaces.

[GRadice]

It is simple, actually. I used a water level with tubing long enough to reach all the posts. Marked level on each post and then layed out the joinery from those marks.

Here is my super expensive and highly technical leveling rig. The green is food coloring.


 

[skatefriday]

Here is my super expensive and highly technical leveling rig.

Well, that's why I asked.  I would have never thought of that  :-)

Although now that you reference a water level, I'm reminded that when I was in my very early teens my grandfather had a Volkswagon camper van that he had fixed a clear plastic flexible tube up the exterior side from the water tank so that he could tell at a glance how much water he had left. 

[beenthere]

With the water tubing, be sure to get semi-rigid tubing.
Soft rubber tubing (surgical tubing) that will stretch and spring back to original shape can change the observed water levels, if I recall correctly.
Some laboratory tubing that I used was a nightmare when trying to level with it. Some stiffer side-wall tubing as shown will not do that.

But I found a leveling transit for a few bucks on eBay or Craigslist that has a scope on it that could be used to run a level line. Recent developments of laser transits may be another, but more expensive method.

Will depend on how often one wants to shoot a level line, and I'd think building a timber frame might warrant a small investment instead of dragging out the water tubing.

[GRadice]

With the water tubing, be sure to get semi-rigid tubing.


Will depend on how often one wants to shoot a level line, and I'd think building a timber frame might warrant a small investment instead of dragging out the water tubing.

Yes, good tip. You don't want tubing that stretches.
Again, yes for larger scale and repeated work a laser level or transit would be great.
In my case, the frame is only 6 x 9 feet and I won't be doing any timber framing after this project. A water level was just the ticket. A few bucks for tubing, no batteries, accurate to less than a mm, as reliable as gravity, and I don't have to worry about anyone stealing it!

[GRadice]

Although I haven't posted for awhile I've been working on the frame every day. I have test fit all the joinery and the last step is making grooves for various panels and trim pieces. Today a friend and I cut all the long grooves for the wall panels. They are 18 mm wide and 9 mm deep.



 


For these I used a Makita groover. Here it is on some scrap:

Makita groover - YouTube

The cutter I used has two wings. Here is one. (4 wing cutters are available, too). The moveable zero clearance inserts did a good job eliminating tear out.



 

I'm still on track for a frame raising on the 29th.

[aigheadish]

I don't think I've seen a groove cutter before, looks pretty dang handy!

[GRadice]

Frame raising tomorrow! I'll post pictures when I get a chance. I might have a time-lapse video of the raising, too.

Wish us luck!

Gary

[GRadice]

Started at 8:00 am. Got it all assembled, plumbed, pegged, and wedged by 12:30 pm. It was a little nerve wracking but there was plenty of good-natured and competent help. A few joints could have seated a little better but overall I'm happy with how it came together.

There will be a time lapse video of the raising in a few days.



 

 

[Tom King]

It's a work of art and craftsmanship, and I'm proud to "know" you!

[GRadice]

Thanks, Tom. I appreciate the kudos from someone with your experience.

For giggles, here is the time lapse video of the raising. I started with a little safety spiel and orientation, then it was off to the races. 4 hours compressed to about 6.5 minutes.

https://youtu.be/c7pXw2znRWw

[aigheadish]

Wow! Well done! This is has been a great journey to take with you and it looks really good! 

[GRadice]

I'm finishing up the details on the barge boards. I added a stopped rabbet on the lower edge, and have almost finished the pendants. There are many and more elaborate designs for gable pendants but I've chosen a simple one since this is a shed and not a temple or tea house. They will be attached by dovetailed keys. Mostly done except for some beveling and finishing the keys and a wedge. In keeping with the rest of the build this is all wood joinery, no metal fasteners.






 

 

 

[GRadice]

Got the barge boards up today. Since it I cut the joinery for these almost a year ago I was sweating how well it would go together. The first set took a friend and me about two and half hours with some mounting, head scratching, dismounting, discrete joint surgery, and repeat. One eave beam end had curved inward about a fat 16th" and with the tight tolerances of housed joints it brought everything to a halt. We learned a lot from that experience the other end was fine so the second set went up in about 45 minutes, including time to move scaffolding. The joinery is mostly clean and tight and definitely solid. 

Quick note: in simple traditional construction like this the rule is that barge boards are the same width as the rafters but twice as tall. Simple rules like that make what can be otherwise pretty complicated much simpler to lay out.




 

 

 

[JRWoodchuck]

Everything looks great from where I'm sitting!

[GRadice]

Rafters up now. Trying to get the roof on before the rains begin again.



 

[GRadice]

A virtue of building a tiny project is that it is relatively easy to cover when it rains. Today we had our first rain in about three months. A welcome all-day drizzle. Got the tarp on last night. 





 

[GRadice]

Still working on the roof. It is taking awhile since there is a lot more joinery involved than in Western carpentry after the rafters are up.

Here is a schematic of the system I'm using. There are lots of variations of this in Japan, some much more complex.



 

Conceptually this is two layers of frame and panel. Sitting on the rafters is a perimeter frame 36 mm (about 1.5 inches) thick that is set back from the rafter ends 15 mm but overlaps the barge boards by 15 mm. On top of that is a second frame also 36 mm thick that overlaps the rafter ends by 15 mm and also the lower frame on the barge end by 15 mm. That creates a secondary drip edge beyond the rafter ends and barge boards. The lower frame is screwed to the rafters to keep them in line and prevent the ends from sagging. The lower frame also hides the end grain of the ceiling boards that will sit on the rafters. The upper frame hides and supports the plank decking above the ceiling boards. Some furring strips also support the roof decking as well as help stiffen the exposed rafters.

Both frames have the same joinery. The corners are mitered to eliminate exposed end grain. There are a bunch of ways to join the miters but I chose to use a haunched and through wedged tenon. In this part of the frame the left arm is Port Orford cedar like the rest of the shed components. But i ran out of dried POC stock of sufficient dimension for the rest of the roof frame. Fortunately I found some yellow cedar (aka Alaskan yellow cedar) locally that was dry and ready to use. Both are light and strong and rot resistant and age to a silver gray so I think it is a good substitute.



 



 

The long arms of the perimeter roof frame are a little over 13 ft. I didn't have stock that long and my shop layout is limited to working 12 ft stock anyway, so I used shorter stock and added a splice joint. This is one of several traditional Japanese splice joints used in this situation. From Chris Hall's monograph on Japanese splice joints. As you can see, the frame will be screwed to the rafters.



 

And here is my attempt.



 



 

And then there is the joinery for the two gable frame rake boards where they meet at the ridge. Here is the scheme I'm using, from a Japanese carpentry book. One great thing about this carpentry book series is that the measurements are proportional so you can use them no matter the dimension of your stock. Brilliant! This is the view from the roof side, not the show side:



 

And here is my attempt before cleaning it up. It did take a while to visualize the layout but I think I got it right. For me this is the fun stuff. All hand saw, plane, and chisel work.

[GRadice]

Floor joists are done. They sit in pockets on the perimeter floor beams on the short sides and in cogged lap joints on the sleepers. All screwed down.



 

 

 

[GRadice]

One more thing on those cogged lap joints. They are meant to fit tightly. In Japan a common method to ensure a tight fit is to make the width of the long grain member of the lap slightly oversized. Like a fat 1/64th" or thin 1/32", and then compress it with a hammer just before assembly. The technique is called kigoroshi, or "wood killing." After assembly, the wood will swell with increases in humidity or a spritz of water. This works better with softwoods than with hardwoods but can be done with both with experience.

The style of ryoguchi style hammer I'm using has a rounded face on one side designed to use for this technique. It worked great with the Port Orford cedar I'm using. Here is a video of work in progress.

kigoroshi 1 - YouTube

[GRadice]

Ceiling boards. More POC that I've milled down from 10 foot 1x12's to about 5 ft and 3 ft, 5/8" x 5",  then ship lap them. Boy was that a slog.



 

Some of the boards were gorgeous and some weren't so pretty. Knots and such. I realized while working them down to finished dimensions that I could band saw off about 1/8" veneers from the good boards and laminate them to the bad ones. Like this.

Bad board.



 

Laminated veneer from the edge



 

New show face:



 

That took awhile, and a lot of glue. All just part of my quest to get the least amount of shed for the most amount of effort! Now on to finish planing the show sides.

[GRadice]

All the ceiling boards are finish planed on their show sides. It went a little faster than I thought it would: about 12 hours over 5 days to do about 160 square feet of planing, including time to re-sharpen about every 3-4 boards.



 

I also cut a bunch of furring strips for the roof. These are Douglas fir.



 

And made a ledger/false ridge beam to support the plank decking, underlayment, and metal shingles. It is a chevron shape, about 13 ft long, 2.5 inches wide, and 3 inches tall. I made it out of 4 pieces of western red cedar. I decided to play with a splice joint. Probably not strictly necessary. The whole piece will be screwed down to the underlying ridge and I could probably just butt join it. But I like joinery and it was fun to come up with something new that worked with a chevron cross section.

I cut the pieces that would make the chevron in half lengthwise, and cross cut two to just over 6 ft and two to just over 7 ft. Then cut this Japanese "crossbill" joint to splice the halves.




Then cut the chevron profile on the top and bottom surfaces and glued the lengthwise halves together, back to back, offsetting the crossbill joints on the two halves.



  

 

 

And done:



 

And in case it isn't clear how all this is supposed to come together here is a rough section through the rafters near the ridge. From bottom up it is rafter, lapped ceiling boards, furring strip, plank decking. You can also see the ridge beam and the chevron shaped false ridge.