Hello, My name is Paul Grim, just registered, 1st time TF builder. I have one small cordwood masonry bathhouse project under my belt but other than that I am relatively inexperienced builder. My wife and I would like to build our TF house using all home harvested lumber from our property. We live in semi-arid Oak Savannah land and have thousands of White Oak trees. Most of them are scrubby and not useful for building. However, taking an inventory I suspect we have nearly 100 usable oak trees. However, I'm not positive they are big enough which is my first question. I think we have plenty of posts. 8-12 feet long, straight, and over 1 foot in diameter. We will "box the center" and use heartwood for each post. My math shows I can get about 6x6, 7x7, or even larger out of these round logs (or something like a 9x4 and a couple of 2x6's depending on the starting diameter). Looking at all of the timber frame designs, these pieces seem smallish? I see a lot of 8x12 post and beams out there in TF books. I'm thinking our wood will be very strong because it is CENTER CUT OAK. However, I don't want to start logging my property until I am sure my wood size/quantity is feasible for the project. I suspect that beams may be my real problem. We only have a handful of oak that is 20' long or better and the log diameter is only about 12 inches (including bark). We don't have a lot of money but we have resources and stamina so I prefer to get all of my wood from home. We are willing to use extra posts to make up for the small size of the wood and we can scrimp and save to buy a few large salvaged tie beams if necessary. We will probably NOT use joinery so that actually increases the effective size of the wood, yes? We have metal worker friends who will make metal connectors for us. Our house will be a Colonial design with lean-to ("broken back barn") about 1400 SF, 1.5 stories. Sorry to be so wordy, but my question is; does the project sound feasible using our home grown lumber? Thanks for your time.

Left out 1 very important thing: We don't have a house design to tell us what wood we need because we are designing the house based on what wood we have!

Hi Paul, welcome.

short answer: of course, YES!



6x6 and 7x7 are certainly sizes that will allow for all kinds of flexibility in your design. Post and beam sizes can also be solved by laminating multiple pieces together with metal bands and shear blocks, so no problem there.

I would say that anyone who gets to start their process by looking over, and choosing from, thousands of oak trees is sitting about as good as it gets. And having metal work at your disposal is definitely a wonderful luxury. And not trying to stuff your material into an existing, and maybe inappropriate, design, is exactly right, too.

In fact, I am jealous and would welcome the luxury of having that situation at my disposal before I started designing.

Your main issue is going to be time and moisture content. Using fresh cut, green oak as your material necessitates you realizing that this wood is going to move, and twist, and shrink significantly during it's drying process. Utilizing steel connectors will allow you to not have to worry about the structural integrity as much as if you were talking traditional joinery, but you should be aware that things will be moving a lot for the first few years.

Bucking the logs to general length, debarking them, covering them, and letting air circulate around them for a year, or two, wouldn't hurt my feelings at all. Plenty of structures have been put together with green wood and were just fine, though, so perhaps some more research on your end might help you determine what meshes best with your aesthetic.

For interior planking and such, you really should mill it, sticker it, and let it dry, under a tarp or roof, for 1 year per inch of thickness. 6%-8% would be ideal before working, though you probably won't get it that dry. Oak will literally explode itself apart if improperly installed while wet.

You should check out R. Bruce Hoadley's book, Understanding Wood, too, as it is a cornucopia of knowledge.

Cheers, Chuck

Those larger timber sizes you referred to are usually for pine or doug fir. Hardwoods, especially white oak, is often used in the sizes you mentioned in old barns due to it's greater strength, but in the end actual engineering/load calculations need to be done to confirm dimensions needed for the situation. That's why I'd say work on your design. Address all your needs and what you want. Get a design and get the loading/stresses and beam sizing reviewed professionally. Then figure out what you can use of your trees. If you need longer pieces, like for tie beams, or principle rafters, you might have to order some from a mill, or investigate what reclaim might be available to you. I have a bunch of reclaim that I'll be using for my home project as I don't have any of my own trees. Actually, if I were you, I'd want to preserve as much of my own trees on my property as possible.
One very important thing you will need to be able to do is select quality timber for each member. Framers learn about how much grain runout is and is not acceptable (1 inch in 15 is what I learned) for things like tie beams and rafters. You need to learn about knots, their type, location, size, and number that are acceptable for a given member as well as other things that would be considered defects. Learn what is acceptable checking and what is not. I learned from the instructor in my first timberframe workshop, and by reading, studying and understanding the NELMA grading rules for timbers. Posts, which are in compression, can usually be a lower grade than ties or rafters, but you still have to recognize what must be culled.
12 inches including the bark isn't very big, especially when you subtract the bark and the sapwood. Have you also discovered forestryforum.com ? There's a lot of experience on logging and milling timbers there. Also how to stack and sticker and properly air dry. You do know to seal the end grain right?
Again, I think you should focus on design first before getting too much into your timbers, but you can keep in mind what you have available to keep your design lengths in line with what you will have, or plan to go outside where you need longer or bigger stuff.
Lastly, keep in mind that making the bracketry isn't cheap and requires a bunch of work too. That direction is fine if that is what you want, and for the reason you mentioned. Don't be fooled thinking it's much easier than regular joinery. It will require similar precision layout and cutting, and fitting of the hardware and precise attachment. Among many reasons for using traditional joinery is that metal will react with the wood over a long period of time. But post and beam structures will still last a long time.
Hopefully some of my points give you things to think about. I have gone through the learning process over the last several years myself and have learned a ton from people on this site and the forestryforum. Keep up the questions, as we love answering. One of the main purpose of the guild is teaching/learning. Consider joining the guild too if you haven't yet. Great publications(Scantlings monthly newsletter and Timberframing magazine which is bimonthly or quarterly), and gatherings. I've been a member for 3 years, and just went to my first events this past year and they were great. Welcome!

Preserve trees to what end?

End sealer is not the only way to go.

12" is a good size tree, depending on where it is measured, sometimes that would be excessive. A little wane and sapwood is good for the spirit.

Just a few additional thought to go along with Brad's post.

Tim

I'd like to also comment on the design first, then figure out what timbers you'll need, as mentioned keep in mind the limits to your log lengths, next create a log list (this is a list of the sizes (diameters) and lengths of logs you'll need).

After you have your log list then go to the wood ands and see if you can fulfill your log list.

I see it the other way around, Jim. Otherwise the chances of the design being filled via the wood avaliable is reduced. Take a reasonable inventory of the timber first and apply this to the design.

Tim

Thank you Chuck! Appreciate your optimistic attitude. My plan is to cut my Oak in a couple of weeks, let it "cure" until this summer (using standard guidelines of course), frame the house, roof the house, and then let it sit, unwalled for 1 year hoping that we have enough money for walls next spring... Thanks for sharing your knowledge.

Thank you all for your time and knowledge. I tried to reply to each reply, but it groups all of my replies together at the bottom of the thread. Is there a way to "nest" my responses?
My wife and I are social workers and have meager income (anybody want to trade counseling for design work or joinery? . That's a large part of why we are limited to using our own timbers and why we may have to design the house based on the wood. Also, (not trying to get political) I simply believe I should use my own timbers for many reasons which I shall keep to myself. Even so, it IS difficult for me to cut down my beloved trees, but I know I will have great respect and affection each time I gaze upon them in my house We are doing a LOT of research. I have read nearly every page of every timber frame book I can get my hands on. I have been practicing using the math to calculate loads and feel confident in my abilities to evaluate wood for strength given run-out, knots, etc... (I come from a long line of engineers) I have been making use of Pythagoras non-stop and incorporating Euclid for the Golden Ratio. Anybody use the Golden Ratio in their design work? My plan is to buy a chain saw mill to do the cutting (Alaskan?). Experiences? I'll search the forums. Thanks again for your responses. From them, my impression is that I am not totally delusional in my vision for our home.

Sounds like a dream coming true. I think we have some stuff on here entitled "Fibonacci". If you are confined to your own trees, (which I agree with you will be complete fulfillment when you gaze upon them) I would side with the inventory then design.

Remember there are a lot of folks around here that can help you with your process. That is which can be conveyed through type and pictures.... We like pictures.

Sounds awesome and keep us posted. Very Cool.