Designing a TF woodshop

Hi everyone. I am going to probably violate forum etiquette here by posting a bit of a dissertation on my first post, but I will give a bit of background first and maybe you won't hate me too much.

I am what I would consider a "traditional woodworker," my focus being on using old hand tools. I don't build anything spectacular (part of the joy of having young kids and hobbies - something's gotta give). I do enjoy my hobby when I can make time though.

At our old house, I have the detached one-car garage entirely to myself. It was insulated and heated with a wood floor and made a very nice woodshop. Since I don't have a tablesaw or jointer or anything like that, the 13x19 space was adequate.

Now, at the new house, there is a two-car attached garage that is being used *gasp* for parking! I have been given permission from SWMBO to build a shop in the back yard. I have been hemming and hawing over this since before we even moved into the house. The only thing I know for sure at this point is that it will be around 12x16 since anything under 200 sq ft requires neither a permit or a permanent foundation in our town. A member of my woodworking club works for the railroad and has said I can have all the creosoted RR ties I like (12.5' or 16.5' - erfect for my layout). So my shop will sit on RR tie skids.

The "neanderthal" faction of my woodworking club, which consists of about 4 guys who meet monthly for anything related to handtools and traditional methods, let me know that we would be building a timber framed shop for me (gotta love good friends who help you on your way like this).

One of these guys teaches classes at Tiller's International and knows the fellow there who teaches timber framing. He has agreed to do a timber frame class for us to build my shop at their site, and then do a raising at my house. We have a handful of people willing to do the class. Basically I have to pay for materials and a class fee (~$200) and I have a timber frame. All I have ot supply is a sketch of what I want to build.

And there lies the conundrum. Outside of the 12x16 footprint, I am not sure what I want to build. If I lived in a colonial or something like that, I would just go with the traditional 12/12 pitch roof shed design found in so many timber frame books. However, we live in a mid-century quad level with a low, 4/12 pitched roof, and I (read: my wife) would like something that "goes with the house." I am all for it. Despite my anachronistic tendencies, I actually really like mid-century modern stuff. The inside of the shop can be rustic/cozy/whatever, but from the outside, it needs to fit in with the neighborhood.

To get an idea, here is the house:



Something in this format, won't work so well:



That would be ideal from a practical standpoint. I would love to have the loft space for storage, but the roof would be visible from the front of the house, and that won't fly.

Something on the modern side, like this:



would be the right look, but I give up a lot from the standpoint of that loft storage.

I was wondering if anyone here had run into anything similar or might be able to point me in the direction of some designs that would fit from a style standpoint while suiting the functional needs. Also, I just need some designs to show my wife for a buyoff. To her, timber frame means rustic/barn/grazing cattle/etc. I have been trying to find good TF examples of modern structures. Essentially, I need something that fits in a 200 sq. ft. footprint and can reasonably be built (the main joinery, at least) in a a 3-day class.

Anyway, if anyone has any feedback, I would love to hear it. This appears to be a great resource. Also, if you are in SE Michigan, I would love to hear about it.

Thanks in advance!

-Jamey

welcome aboard Jamey, sounds like this will be a great project, hope you'll keep sharing your experience with us...
one great design comes to mind for a small low pitch building from one of our own here:
http://www.tfguild.org/forums/ubbthreads.php?ubb=showflat&Number=24598&page=1

you might have to work on the missus to get over the whole horse shelter thing..lol but with a few windows and a door this can turn into a great little shed..

Hello,
It's not the exact time frame you mention but the arts and craft movement did use large dimension timber in house architecture in combination with a 20th century mindset if I can put it that way. Low pitched roof line, Lots of glass that sort of thing.

How do you handle rafters in a roof that doesn't meet at a right angle? I suspect this takes some creative truss work? One thing I am considering is a longer overhand on the front edge of the roof and actually angling bracing out to have full-height windows that lean out 10-15 degrees or so. This is reminiscent of my late father-in-law's Art Deco house in Lansing. I think the extra space afforded without increasing floor space would be nice. Running a shelf along the windows at about counter height that doesn't intrude into the room would be a neat feature, I think, and quite useful in a shop environment.

I'll try to work up a concept and post a picture.

I would suggest looking at craftsman style or Japanese timber frames. Both of these often use low sloping roofs like you want to. The exterior can be designed to look however you like so don't get hung up on the aesthetics of those styles, just look at the forms and frames. Good luck.

Perhaps like this wood shed I built 10 years ago.
I had no idea what I was doing but it turned out pretty good.
This building is 8x20 and is made from 4x4/6 soft maple timbers.

Jamey,
Look in the Guild's book "14 Small Timber Frames". There are a number of small, low roof pitch designs in there.

Hi Will. Duly noted and ordered. Thanks!

I have been messing around with a new design that is inspired by the modern house my father-in-law lived in. It was sort of a mid-century design with the front bank of floor-to-ceiling windows leaning out at an angle. I have tried to mimic this here. I kept the 12x16 footprint. The roof is at a 15 degree angle. I should revise it to a 3/12 or whatever would be close to that. I know I need to revise the frame at the roof peak to accommodate the pitch, but this is for a general design sense.

I would be interested in hearing about any concerns or ideas about this design. I also revised all the timbers to 6x6, which I would suspect is sufficient for this scale. Rafters are 4x6.

I managed to leave enough space above for a small storage loft. Not a lot of headroom, but I wanted to keep the profile of the building fairly low.

You are probably looking for feedback on the timber frame, but I'll throw out one other item. Many roofing manufacturers will not warranty their product on slopes less than 4/12. If they will, they often have special requirements for underlayment/flashing,etc. This may not be a concern for you since this is not a house, but keep it in mind when thinking about the roofing.

I'm back with an updated design and would love some feedback. I have finally found a good source of trees for timbers and will start on this project as soon as I can get there to cut and limb the trees and get a sawyer in to mill the beams (poplar and ash).

The intended location of the shop has changed and I am back to having it facing due south. As such, I wanted some bit of the roof facing south for the potential to accommodate solar panels in the future. I also realize that with the footprint (12'x16'), I need to include a storage loft. I came up with this design allowing for transom windows with 4/12 roof pitches front and rear.

What I don't know is if the support for the mid-wall on the loft level where the transoms would be is acceptable over the tie beams in the bents. All beams shown are 6x6 nominal. Rafters are 3x10. The loft is only over the rear half under the higher roof. Not sure how to deal with supporting the end rafters at the upper end of the lower roof, so I would be interested in strategies there.

Very similar to the Appalachian Trail Shelter in "Fourteen Small Timber Frames" by the Guild and designed by Will Beemer. Ties were 8x8's in that condition, and not loaded with a point load at dead center. My gut tells me that this is a little light. Especially if there are any penetrations in those ties...like a mortise and tenon joint...

I agree with Paul.

And a let-in ledger with some structural screws should work for the lower rafters.

I would change timber sizes a number of ways just based on a visual evaluation and then calculate to verify.

Increase posts to 8 x 8.

Increase ties to 6 x 10 on gables and 8 x 10 in center.

Decrease rafters to 3 x 6.

Increase plates to 6 x 8.

Add upper level braces.

Extend rafters at peaks to create overhand.

Bracket support the upper end of the lower course rafter on the overhang.

Roger, on the upper level braces you mention, can the braces be used on the lower side in order to keep the transom area more open for windows? I would like to allow as much natural light into that area as possible. Basically, put the braces running from the beam that runs from the midpoint of the ties up to the secondary posts on to of the ties (rather than from those posts to the plates)?

If it isn't clear what I mean by that, I can update the model and post updated pictures.

All of your other recommendations make sense and I will implement those.

Any value to offsetting the secondary posts and the beams between the midpoints of the ties? I suspect with the mortises offset, it can only be better for the strength of the ties. I would probably leave the secondary posts where they are and either make the loft deeper or shallower.

Paul, the inspiration came somewhat from the Appalachian Trail Shelter. With my smaller footprint, the loft couldn't be offset quite so much. The advantage to their larger footprint was that the secondary post came down off-center on the tie and was near the brace.

Sorry about the delay in answering, yes you could just keep in mind that the braces will impart thrust andd the joinery in the beams and posts must be able to contend with the forces.

Here's an updated version of the frame. The let-in ledger makes a lot of sense for the peak of the lower roof. I extended the gable end overhangs a bit too as the roof on our house has very deep overhangs and a 4/12 pitch, so I will not deviate too far from the house style.

We will be felling trees for the beams on the 24th in Toledo, OH, if anyone wants to come sling a chainsaw for a few hours. We'll pick another weekend to bring in a sawyer to cut the beams. If anyone wants to bring logs to cut up, let me know and we can help defray the cost.

Jamey,

Think about pulling that ledge out a bit, so you don't have to remove so much material from the posts. Here's how we are doing it down at the upcoming Frankfort Kentucky project:





We are using 8x8 queen posts necked down to 6x8 above the lower purlin, so the purlin has a 2" shelf to sit on. Screws from the outside face secure the lap.

That's actually what I had in mind, but I was sneaking in design work at my real job, so I was rushing. I'll definitely make that adjustment on my next revision. Thanks for the feedback.

We will be felling trees on Sunday morning in Toledo, Ohio if anyone is in the vicinity and wants to come out and help/watch/commentate/eat donuts. Just let me know.