A 6x6 based timber frame?

Although I've been perusing the TFG forum for years, I don't get a lot of time for it; hence, the lack of posts.

Regardless, I'd like to get some feedback on a question I was recently asked. In short, I've been asked whether or not a frame -- based on 6 x 6 timbers -- can be cut to support a small- to medium-sized utility building (roughly 12 x 20). For the sake of speed, pre-engineered roof trusses will sit atop the frame, so the frame will not be a bent-type design and, furthermore, it is understood that the plate beams themselves will have to be of a greater dimension ( i.e., 6 x 9).

Considering that a pressure-treated sill plate is what I would prefer to use in this design, I will probably be restricted to 6 x 6 timbers from the lumber yard and, considering that the actual dimensions of said timbers is more like 5.5 x 5.5, I'm a bit concerned about the strength of square-rule joints in such a small piece of [soft] wood.

I was taught to opt for 2" mortise/tenons in softwood, so the fact that most of the timbers in the proposed frame are actually 5.5-inches wide (on each face) brings the one-third frame rule directly into question. I'm also a bit concerned about the general lack of relish when pegging 5.5 x 5.5 frame members together, as well.

I've seen a design for small buildings where half-laps were employed for most of the connections. In this particular design, the half-laps for the posts are cut 3/4" short -- at the bottom and the top -- to allow for shrinkage of both the sill and the plate beams. Obviously, this means that half of the post bears on the sill beam, while the other half has no contact with the foundation. In other words, half of the post simply hovers above the floor and waits for the sill beam to shrink.

By the way, the foundation for this building -- a raised frame made out of dimensional lumber and connected to treated pilings -- is already in place.

I'd like to read a few thoughts on putting a small frame such as the one I've [attempted to] describe together.

Thanks for your time ...

Normally with a 6x6 timber you would make your mortise and tenon 1/4 the thickness. That means your mortise and tenon would be 1 1/2" instead of 2".

I don't know if that helps you or not.

Jim Rogers

That has Dutch framing style written all over it. A Dutch (house) frame has bents that are closely spaced, generally 3-4'. The tie beams are the only floor joists, that is there are no joists running between the bents. Certain 2x T&G decking (generally SYP and DF) can span between the bents. This is the standard frame workshop taught by Jack Sobon and Dave Carlon and Hancock Shaker Village.

I agree with Jim on the mortise. Maybe even 1.25".

I was thinking Dutch as well.

Thanks for the replies, folks. Is the "Dutch" frame mentioned herein based on small 6 x 6 (5.5 x 5.5 actual) softwood timbers? If so, I'll certainly look into that design for guidance...It doesn't hurt that Jack Sobon teaches it, either. That's a pretty good endorsement, in my mind.

The Hancock frame up until I think 2009 uses 6x6 plates and posts, with 6x8 tie beams and 7x8 sills. If you are not putting joist pockets in the sills, you could probably get away with smaller timbers. From 2010 on, the frame was shrunk from 14'x16' to 12'x14'. I know the rafters are smaller, 4"x5" and the posts I think are smaller.

2009 Hancock frame with a 12'x16' addition that I designed and cut:



2014 Hancock frame:



I think you can click on the image to get a larger view. You can see the close bent spacing that allows smaller timbers to be used.

On the 12x14' Dutch style shed he uses 6x6 posts and 4x6 rafters. On the 14x16' Dutch style house he uses 6x6 posts and 5x5 rafters.

Jim Rogers

PS. I have cut several of these 14x16' frames, but as yet to cut the 12'x14' frame.

Thanks again for the posts, folks. Clicking on either photo links you to a series of photos. I hope you don't mind, Dave, but I went through your "album."

What kind of mill do you own? What species is that incredible log being skidded out of the forest with the Timberjack (the log requiring a helper axle)? What kind of a timber did the bottom of that log render? It must have been quite the beam.

Looks like the ideal setting for a timber framer...beautiful.

I have a 2008 LT40 Super with wireless remote. That long log is a white pine. I took it whole just to see if I could. It would have made a 68'-6" 12"x12" with no wane. I ended up cutting it up into smaller bits for a local framer.

Wireless remote? Man, I think about the benefits of that evolution in milling just about every time I walk around the end of my mill to square cants.

As for the log, we had a huge EWP blown over in a microburst back in 2008 that rendered a nice 12 x 12. It ended up being about 24-feet long, however. Nothing like that monster in your photo -- good on ya.' Is that particular log out of your own woodlot, Dave?

It was from my neighbors place. There was some really nice stuff there, but I found a lot of rotten hearts when I got them home. I got some even better stuff from a place across the valley from me, but it's hard to find the stuff I'm looking for. Got a request for a really nice 10"x21"x30' timber yesterday, but I can't find the logs, and to get only one log is even more costly.

Here's a nice one from last summer:



Here's a thread on some of the logging I did last year:

Logging.

I really like the photos of your mill, Dave. How much "control" does your remote unit actually give you? Can you control the hydraulic functions as well as the head functions with the remote?

Hydraulic functions are still on the mill. Accuset still has to be changed on the console. All other functiins are on the remote, such as autoclutch, debarker, etc.

That log would have made some nice clapboard siding. Its not too late!

Thanks, Dave. What are your thoughts on upgrading an LT40HD by adding accuset and an auto clutch?

The clutch is one thing, it can be lived with, but I've come to think that the accuset function is more than just an "option" -- it's almost a necessity.

I really like the Accuset2. My mill is a Super, so the head moves up and down pretty fast. Without the computer, it would be hard to hit the mark quickly. Autoclutch is very nice as well. I guess I'm spoiled with my bells and whistles, but I don't really want to be without them now.