The slow economy in Japan has forced some changes in 2×4 housing here. I have to face one new change on the next house I have to frame/finish for a company here. The stud pitch here is 18″ OC, and sometimes 16″OC. All the houses I’ve built here in the past have been 30″ crawlspace foundations. On the sills we use plastic spacer blocks (1″ thickness, 8″ wide) and anchor the 4×4 treated midsills on top of the spacers. This allows for a vented crawlspace. After that the 1F joists are usually 18″ OC, 2×6 or 2×8.
These days, many companies are switching to using treated 4×4’s, 18″ OC, running lengthwise from mudsill to mudsill. The 4×4’s inside the crawlspace become the floor joists. They are supported with adjustable plastic legs down to the crawlspace pad. Then, to sheath the system, they use 28mm (1 1/8″) T&G plywood.
I haven’t done one of these floor systems yet, and am going to object to doing it, but need some input – Can anybody find potential problems/weaknesses with this system? Would appreciate some ammo to use for my arguement…!
Replies
Any chance we could get some pictures of how yuo do things over there?
I'm sure that a whole bunch of us would be interested in seeing them.
Ok, have attached a few pictures of a log house I built this past spring...the foundation/1F joists are a little different than what I was just talking about, but they are ok for reference purposes.
I'm building a Japanese traditional house right now (Post&Beam framing), but they have nets up around the whole house (on the scaffolding), so I can't really get any good pictures....maybe I'll try taking some indoors tomorrow. I'll post some pics, for reference purposes, but after doing this one Japanese style house, I'll never do one again....the mortise work is really nice, and goes together well on the first day, but after that there's a lot of work to get the structure ready for drywall, etc.
Scott
Thanks for the pics. Never seen anything like that before.It will be difficult for many folks here to download pics that big. It's generally better to re-size them to about 800X600 or so.
Feel lucky? Update your software!
I'm not sure what your objection is--will this system be more difficult to install, or less serviceable?
No doubt a lot of us would be interested in seeing pictures of everything you are doing. Care to show photos of an entire project as you build it? Also, what is your truck in the background in the first picture?
Oops! I should have re-sized the pictures... the truck in the background is a Japanese K-Truck. They are the standard vehicle for carpenters, tradesmen here. Needless to say, I don't own one - I'm 6'2" and can't even get into the drivers side of a K Truck. They are handy though. All are built 4WD and can go virtually anywhere because of their small size and small wheel base. A new one sells for about $7700 US.
The next project I do here I'm going to document from the beginning to end.
Scott
The 4x4 post and beam system is similiar to what has been used around here in tract housing. Except here all the beam joints have to be gusseted for seismic , 1/2 " ply ea. side.
Here it is un treated 4x6/8 at either 32" or 48" O.C., sheathing is plank, T&G 2x8 or 1 1/8 ply or OSB.
This system is not known for producing flat floors.
I am curious about the plastic under the post though , is it for shimming, or for some seismic reason?
Dang...send me a K-truck...
My old Caravan, the perfect dual purpose Mr. Mom/work van, is reaching it's end of service life, & I really don't want to buy a full size van ;-)
Gotta say that that's an interesting way to insulate the floor. Would be a good option in the US, in areas of moderate temperature.It's odd to use 4x4 as joists, vs 2x8, eg. Same amount of wood, but the 2x8 is roughly twice as strong, and is easier to treat do full depth.I do wonder to what degree the construction techniques relate to earthquake tolerance. I suppose the 2x8 is more likely to roll in a quake.You guys must really like to use concrete!
People never lie so much as before an election, during a war, or after a hunt. --Otto von Bismarck
1F = first floor??
New 4WD for $7700 US. I'll order three.It is great to get a thread like this. As a cabinetmaker, I have over 30 books on Japanese architcture and furniture.Chuck slive, work, build, ...better with wood
Please keep posting, and putting up pics. It's great to see options<G>
Abe says, "Man, you must be puttin' me on"
God say, "No." Abe say, "What?"
God say, "You can do what you want Abe, but
The next time you see me comin' you better run"
Well Abe says, "Where do you want this killin' done?"
God says, "Out on Highway 61."
I would love to see pictures of a whole project- traditional style or modern. The company I work for does some japanese style timber framing once in a while, so I've got a real interest in it.
What measures do you have to take for earthquakes? I'm suprised that I can't see much in the way of holddowns to the foundation in those pictures.
zak
"When we build, let us think that we build forever. Let it not be for present delight nor for present use alone." --John Ruskin
"so it goes"
I live in southern Japan, in a city called Oita, and we get earthquakes all the time. In the house I'm building right now, the hardware for earthquakes is incredible. Its a Japanese P&B house, which we put together in 1 day, but it took us nearly a week to do all the hardware. Holddowns in 8 locations, smaller holdowns on all the posts top and bottom, holddowns on the X braces in 40 locations, and the list goes on and on.
The structure of the house is all machined, so it goes together nicely, perfectly, but the finishing of this house is a real task. Compared to 2x4 methods, its all backwards. I've been here for 13 years now, and this is the first Japanese P&B I've done, and won't do another, just because the things I learned and studied can't be applied in this house. I'm compiling a list of the differences and weak areas in the Japanese style house if you're interested in reading it.
Don't get me wrong, I love Japanese traditional style homes, but now that the earthquake codes have come into effect, the joinery systems of a traditional Japanese house have been replaced by metal hardware. After that happens, its easier and quicker to build the house in a 2x4 frame.
Cheers,
Scott S
I am interested in your thoughts on the P+B in earthquake country. We're working on a P+B addition now, in the Bay area (earthquake central for the U.S.). It seems like there's no end to the things we have to do to make up for the lack of shear strength in the frame (lots of window and open wall area).
zak
"When we build, let us think that we build forever. Let it not be for present delight nor for present use alone." --John Ruskin
"so it goes"
Japan has been building P&B houses/shrines for hundreds of years, and they've had earthquakes in all parts of Japan for much longer. As far as I can see, they're still trying to beat the quakes...
Last year the 10year warranty system was put into place here, and all construction companies pay a premium to have their houses insured. So, the JIS warranty lays down the laws for the joinery/hardware used in the homes now. The house I'm building right now just passed inspection, but it took us 2 weeks to get all the hardware on, correctly. The architect came 3-4 times to check out work before the inspection.
I'll try and post some pics in the next couple of days if you're interested. Please keep in mind, I'm a carpenter, and not known for my photography. It'll give you an idea of the new hardware we're using now though....
Scott S
Definitely, lots more pictures.