newbie here with a few questions

[IFIXBMWS]

Hello all!
I've been lurking here for a few weeks and my what a wealth of information, before my questions let me give a little background
I'm an auto mechanic by trade and a woodworker by desire, I finished building my bandmill several months ago to offset my
lumberyard and hardwood vendor trips and save some $$ in the long run and had been in the planning stages of a tf addition to my
woodworking shop, well my wife and had been trying for kids for several years to no avail and decided to adopt two young girls after we had taken them as foster kids, well be careful what you wish for! as we are now expecting twins! so needless to say the workshop
is on hold and plans shifted rather than tf shop have decided to build a large "24x48" addition to our existing home and decided to
go tf as it seems to be the fastest way to a roof and for us lowest $$ outlay, our home is a ranch style with 3/12 roof pitch and straight shot across the back with a substantial grade so...plan thus far is slab on grade, continue the 3/12 pitch out 24 feet
shed roof style(at current grade this will leave 9ft ceiling on low side) I have read  "building the timber frame house" by Tedd Benson
and am familiar with mortise/tenon joinery from furniture building. I have a front end loader /backhoe for timber handling and
am no stranger to a saw 3 brothers and lots of friends willing to help and am not afraid of hard work so 1st question is: Is this reasonable to think that I can do this without formal training? 2: how big does a timber need to be to clear span 24 ft (the timber on my property include mature poplar, red oak, white oak and syp) poplar or syp would be easiest as these are the largest straightest timber
but would like a rule of thumb for all of the above, 3: snow load is not an issue as I am in central NC but the only tf house I know well is my mothers built in 1840 and it is a dry stack stone foundation so are there any negative ramifications to tf on slab IE timber to masonry contact?
sorry for being so long winded, I am sure I will be talking alot over the coming months with you guys so just wanted to get it all out!

thanks
Kevin

[Jim_Rogers]

Kevin:
Welcome to the forum.

I will try tomorrow to answer some of your questions.....

Going home now and the computer at home is broke.....so no Internet at home.

Jim

[Magicman]

I'm not your answer man, but I can say welcome to the Forestry Forum, IFIXBMWS.

[Brad_bb]

Welcome!

Without formal training?  I would say to answer your question, I'd recommend that you take a timberframe workshop.  They are usually anywhere from 2-6 days long.  I'm not sure if that's formal training, but it's a good thing.  You will learn a bunch and get a feel for what you will be able to do.  You can get specific design help, if you need it in that area.  You will likely have to get your plans stamped by an engineer (and it's always a good idea even if not required, to have your work checked).  You'll definitely need to protect the tf from the foundation.  You can use a treated sill, or a conventional floor deck.  You're in termite country, so you'll need to plan accordingly so as not to allow any path for the critters to get at your tf.
    Your span question depends on what your putting on it, a full second floor?

[witterbound]

a 24ft clear span is a long way for a timber frame.  I'm no engineer, but I'm skeptical you'll get a clear span that long with a timber. 

[IFIXBMWS]

no second floor just insulation, and metal roof, I can strategically place jacks if required but was hoping not to, I definitely plan on having an engineer review my plans, was planning on a pt 8x8 for the sill, of my choices what would be my best choice for my frame?
syp is plentiful, tall & large and easy on the saw but I am concerned about the structural strength of the wood as well vs using oak
none of the timbers will be exposed and planning on at least a 18" overhang to keep weather off structure planning on pine siding
probably board and batten or ship-lapped

[witterbound]

my frame is syp.  it's a lot easier to handle, simply because of the weight. 

[Brad_bb]

Here you can see that we spanned 24ft with a king post truss/bent in our 2007 Foxmaple workshop frame.  I've seen a similar truss/bent span up to 36ft.  My understanding is that a queen post truss/bent can span up to 24ft.  But the engineering must always be worked out with the actual design and loading conditions to determine if the joinery will be sufficient. 


Here I am working on one of those tie beams.  They were 8X12 white pine I do believe.

[Thehardway]

SYP for the long horizontal members and White Oak for the posts.  SYP strength to weight ratio is greater than that of the oak, hence it is better for spans, can't go wrong with oak posts.  Poplar is good for siding and the red oak would be great for scantlings and shorter horizontal spans.  The White oak will also work well for sills as long as you use a barrier and protect from termites. IMHO don't use a long free span if you have places for posts.  It's not worth the trouble, headache and increase in the size of timbers.

You can certainly do this your-self if you take your time and do your homework.  Don't think it will be quick or without challenges on your first go round.  A good set of large sharp socket chisels, a good mallet, sharp saw and accurate square are absolute neccessity.  Boring bits in a variety of sizes and  machine to turn them is also high on the list.

It's a lot of work but is also very rewarding!

[Jim_Rogers]

Kevin:
Welcome to the forum.

I will try tomorrow to answer some of your questions.....

Going home now and the computer at home is broke.....so no Internet at home.

Jim

I would have to agree with most if not all of the comments posted, giving you advice.

There are several good timber framing engineers, I believe, in your area, or are at least familiar with your area. And they will be able to review your design and help you with it so that it will be safe for you and your family.

To begin you need to draw out the floor plan and get the addition to the house figured out on paper, so that your ideas can be seen by others.

Once that is done then you can begin adding the timber frame inside your exterior walls and get a better understanding of what timbers you truly will need.
As mentioned trying to span 24ft with a 3/12 pitch roof will be a real challenge, so keep an open mind to the final design.

Jim Rogers 

[Rooster]

Kevin,

Welcome to the Forum!

I am having a hard time visualizing how the addition will be added.  Could you draw a simple sketch using a MS Paint program or Sketchup, and add it to your photo album so that we can see what you are looking to build?

Thanks!

Rooster

[Stephen1]

Welcome to the forum..
I will go along with Brad-bb in that I would try to get in on a timberframe workshop. It will open your eyes to layouts and time saving and back saving ideas.
I did my log cabin out of many books and now know I should have taken a workshop in log building, just as every book I read suggested :P
I took a workshop with the Jim Rogers here this summer and it was a great place to pick information. I would definitely  do another TF workshop, with Jim or anyone. I think there is to much info to pick up in 3-6 days, my poor little brain was a little worn out by the time the workshop was over.

[IFIXBMWS]

thanks everyone for the replies, after consulting with an engineer we have come to the conclusion my original plan although feasable just isnt practical so have decided to move back to stick framed with a few large timbers for asthetics, the tie in to existing roof system creates a major challenge and would require more work than it will to saw the lumber to stick build , but after this project
i am definately planning on taking a workshop, just found out my wife signed me up for woodrights week with roy underhill in the spring so i should get a taste of some of it there!

[bushhog920]

Too bad you just missed out on jayson's three workshops in brasstown nc, I am a auto tech and planning to build a tf house too. I would say go to a workshop there are soo many little tricks you can pick up would save alot of pain in the long run.

[Rooster]

Kevin,

All of us here are supportive of your addition project.  Most of us would like to see you succeed with a possible timber-frame.  We were very curious about your project and wanted to know more...You went and got us all excited!  8) So I am having a hard time letting the idea just die with the engineer. :-\

Would it be more feasible for you to build the TF addition as a separate building, with a roof system that is independent, and then use a smaller and simple "breeze-way" connecting structure that is easier to attach to your existing home?

I am sure someone on the forum has seen home additions or even garage additions done this way...maybe they could share a photo or two.

Well, that's just my way of trying to keep the "dream" alive!

Rooster

[Brad_bb]

Isn't practical?  Well a timberframe will usually likely cost a bit more (if you're paying someone) and you could say on a strictly cost: function basis, is never practical.  But that doesn't take into account the differences between stick and timber built and what one gets from the difference in styles etc.