Timberframe Shed Design

[alpmeadow]

The timberframe shed is taking shape.  Thanks shenneman for your input and welcome to the forum.  Please see below the wider spaced rafter system(going 2 ft to 3 ft+ does complicate spacing for roof buildup?).  If I rough cut long timber 6"x2"x16' plus for T&G and air dry(long time) it should work for the roof deck.
Please see below the updated frame image and an image showing detail layout for post IA.  It shows dimensioning from square rule edge for two sides of the timber for joint layout.  It is in xray mode to show joints in sketchup.
Comments welcome. 
Cheers
Irv Graham

[Dave Shepard]

And here is what it looks like from the outside:



This is the original shed at Hancock Shaker Village, not a very good picture though. Last time I saw Jack, he was trying to get me to put a new roof on it. :D Those are nice drawings Alpmeadow, I still do mine on paper.


Dave

[moonhill]

Alpmeadow, I always place/base my brace measurement from the top of the post or from the bottom of the tie, to the bottom of the brace pocket.  Here I see that measurement based from the bottom of the post.  Is that just the way Sketchup calculates the numbers?  You have 6'-9" from the bottom of the post to the bottom of the tie, which I'm assuming is an 8" timber and reduced to 7" at the joint.  Than a number, 3'-9-7/16" from the bottom of the post to the bottom of the brace pocket.  That leaves you with a brace leg length of 2'-11-9/16".  Again, assuming you are housing the brace to 7" on the post and the tie, that measurement should be 36" and giving you a brace length of 50-15/16" from point to point.  (36/.7071=50.912176)  Why 7/16" short?  Also the brace peg is showing a 1-9/16" peg hole placement.  I think you want that at an even 1-1/2" and draw on the brace tenon by 1/8+" in 2 directions.  I see a 1/8" draw on the tenon on top of the post which is correct, and the peg hole on the top plate should be 1-1/2" off the seat.   Does this compute or am I missing something.  Maybe it is just the way Sketchup works?  It seems like a lot of fractions and I like whole numbers for the most part.  Tim B.

[alpmeadow]

Well darned if you caught me with my pants down Moonhill.  Yes my braces have shrunk and should be 50.91" as in my timberframe notes.  Early in my sketchup design I used a tool called scaling and it slightly shrunk my 36" brace. I am rattling through my design to shift every brace into its proper location and size.  I guess I couldn't see the forest for the trees, and extra experienced eyes on the plan sure helps to catch simple errors.  Much appreciated.

Wow, I like the image of the shed.  My course notes confirms, "the 12x16 foot shed garden tool shed featured in this book was was designed and built for the Hancock Shaker Village, a museum of old Shaker buildings in Hancock, Massachusetts."  It nice to acknowledge the historical values of what is being created.
Cheers
alpmeadow

[witterbound]

Shinnlinger,

I don't think you pro-purlin people are wrong either.  Just wanted to point out some of the factors in using purlins vs rafters.

In fact, I'm pretty sure that principal rafter/purlins are now the dominate type of roof system used in timber frames.  I think this began because it's easier to put the bents together on the deck and raise them with a crane, then drop in the purlins, than it is to put up each post, then put a plate on top, then fly in the rafters.  A lot more raising time is typically needed for a post and plate (common rafter) design, I think.

Back before the reinvigoration of the timber frame industry in the US, I think the common rafter system was the primary roof design.  I've never seen an old barn with principal rafter/purlins.  Anyone else seen one?

One advantage of the purlin system is that you don't have to have as many long timbers.

[moonhill]

Yes I have seen them all over the place, principal rafters and com. purlins, old and hewn.  What you are talking about is the Bensonite method, it is not traditional.  Tim B.

[routestep]

On small sheds, I don't think wall plates and rafters are very hard to set up if made out of softwood. A plate can be lifted in place by parbuckling with two men per bent. With 4" by 6" rafter pairs one man can push them in place if the rafters are fairly short.

[alpmeadow]

Golden Greetings
Attached is the Post IA plan drawings of front and side corrected for the brace joints with dimensions added.  This replaces the previous post drawing reply 25 dated March 5, 2008.

This should work for cutting.
Thanks again for input
alpmeadow

[alpmeadow]

To the PM
A question was raised how to setup Sketchup to get a planview of the timber in my previous posting.  I responded as follows:
Thanks for your comments.  In sketchup if you go to camera, standard view, front and this view has the timber shown properly, or select the standard view(top, side etc) that works for you.  Next go to camera view, parallel projection it will remove the 3d perspective that messes up your drawing.  You can still change the standard view  to top or other views as it is still a 3d drawing.
Try it out.
Cheers
alpmeadow

[alpmeadow]

PM received as below.

I like your model of your 12 x 16 timber frame shed. I notice you use 8" x 8" posts. Do you think 6" x 6" would work? Thanks

I responded
6x6 posts can be used however a different design and sizing for mortise and tenons is recommended, and I am not qualified to recommend such alterations from that published in Sobon's book.
This comment will be added to this thread.  Good Luck
alpmeadow

[moonhill]

6x6's could be used, but the joinery will have to shrink as well.  I bump my timber up to 9x9 just for the convienence of the joinery.  Tim

[Jim_Rogers]

PM received as below.

I like your model of your 12 x 16 timber frame shed. I notice you use 8" x 8" posts. Do you think 6" x 6" would work? Thanks

I responded
6x6 posts can be used however a different design and sizing for mortise and tenons is recommended, and I am not qualified to recommend such alterations from that published in Sobon's book.
This comment will be added to this thread.  Good Luck
alpmeadow

Statements like: "6x6 post can be used...." maybe true but you shouldn't be making them without careful review of the intended loads to be put on the frame.
The person who is asking this question should review the frame loads and/or have it reviewed to insure that the 6x6 post can handle the load.

We don't know where the new sized frame will be constructed so we shouldn't just assume it will be ok. Nor do we know what loads he'll place upon the loft area if any.

There are lots of facts to take into consideration, and we don't have any of them here and now to consider.

The frame from the book was sized so that the author could be covered if anyone from just about anywhere built this frame. What that means is that the posts are oversized to handle just about any load. But we can't just assume that building the same size shed that we can reduce the size of the posts to fit our stock on hand or our wallet.

Each frame has to be reviewed for the location conditions and the intended loads for the current use.

Jim Rogers

[alpmeadow]

Hey Jim
Yes, we better say "could" rather than "can".  That's why I bought it into this thread so, wannabe's, just like me, can digest the great content and almost, wise members of this forum.
Sounds like you had a great time at the southern workshop.  What do you do with timbers that the missed layout or cutting marks?  Toothpick timberframes?
Cheers
alpmeadow