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Some questions about timberframing in general

Started by JoeyLowe, July 31, 2004, 06:30:35 AM

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JoeyLowe

Hi all!  I've read wih great interest, many fine posts over the past several months, but I still have some general questions.  To help the readers understand what I'm trying to do, let me explain my scenario.

I'm a Woodmizer owner and over the past couple of years, I've cut quite a few timbers for timber framers.  I've even watched the joinery being cut, although I've never partook myself.  I've never watched a frame erected though, and therein lies the bulk of my questions.

I'm planning to add an additonal 1500 sf to my shop within the next few weeks.  The existing structure is two stories and was built in the late 1800's.  The new structure will be a single story and will have three door bays along one long side and one door bay at the end.  The other long side will have several large windows and the other end will tie into the existing structure.  The new addition will be roughly 30' wide by 50' long.

I joined the guild over a year ago and I've read the numerous books about the subject, but I'm still green when it comes to actually building the structure.  I thought about hiring a design firm to actually design the addition, but aside from their steep fees, they weren't real clear on what I was wanting.  (My fault probably).  The two main design considerations that I see are as follows.  First the ridge of the new structure can't block the view of the existing upstairs windows, which limits the height of the ridge on the new structure to around 10-11'.  Of course, I could shorten or remove the upstairs windows, but I would need permission from the zoning board to do that, and I'm not prepared to do battle with them nimwits  :o just yet.  The second consideration concerns the foundation.  Several designers have told me that I should pour a slab.  I prefer to pour footings around the perimeter and use floor joists.  Any thoughts on this is greatly appreciated.

Well here goes with my questions?

Do I need to purchase the larger beam saws, chain morticers, boring machines, etc. or is there a place to rent these or can other methods be used short of breaking out the handsaws?

I'm assuming that since my ridge is so slow, I will have around a 2/12 roof pitch (if you call it that).  I've acquired many beams of all sizes (mostly 8x 8's) so timber is not an issue.  I plan to use the 8 x 8's for most of the bents.  When joining the bents together ( I figure 4 or 5 bents at max.) Do I continue to use the 8 x 8's or can I drop down to 6 x 6's assuming that I won't have more than 10 feet between bents.

Last question!  Since I won't be working at great heights, I plan to do a lot of this work myself with a couple of helpers.  I have a 6 ton forklift too.  When standing the bents up, I understand that they have to be braced, but when connecting the bents, how do you secure the ties between the bents while standing up each successive bent.  I guess what I'm trying to say is that if you are tying the bents together at the ridge and both sides and all three ties fit into mortices, how do you get all three together at the same time with just one forklift and a couple of helpers.  Any guidance for this old man would be most appreciated. ;D
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Joey Lowe

"Working towards perfection has to be a part of anything one does.  You've got to put yourself into it." ... Sam Maloof (chairmaker)

beetle

Joey,

I am only going to comment on the tool question since I am not a Engineer or a experienced Timber Framer. I am currently in the process of cutting joints on my first timber frame project, a 24' x 36' x two story English style Barn, and like you, I had spent several years researching, reading etc on the subject. Again like you, I had the same questions in my mind regarding tools, do I need or want to buy the bigger power driven beam saws, mortisers, ect, ect, ect. I am somewhat of a power tool junky. Just what I needed..another one of these and another one of those.

I made the decision to try only hand tools first, and since this is a once in a lifetime project for me, I decided to experience it the way it used to be done. I am glad I did, I will finish this barn frame without any power driven tools, it is great and very relaxing. Do not get me wrong, when it comes time for the roofing and siding I am sure I will be breaking out the Chop saws, Nail guns, etc.

I bought old chisels, hand saws, and a hand driven Timber boring machine, I feel I can bore and saw just as fast as the power driven ones in my shop.... and it is fun!  It is cleaner, quieter, safer, and when done, I can look back and say I did it by hand.

So, to answer your question....no it is not neccessary.

I did drop a few bucks on the old tools, but I am sure it is a whole lot less than if I went the other way. I plan on hanging all the tools in the Barn when done.

Enjoy it and have fun.

Jeff
Too many hobbies...not enough time.

ksu_chainsaw

When I helped a friend put up a log cabin kit, he went to Home Depot and rented one of the big circular saws.  When he took it back, he was looking at some of the used tools that they had for sale, and asked about the circular saw.  They depreciate the tools depending on use.  Just an idea that I thought I would throw out.

Charles

Jim_Rogers

Joey:
First of all, lots of good questions.........

My first question to you is about the doors in all the bays. Are they big doors and are you planning on driving equipment such as fork lifts, and pickup trucks onto this new floor area?

With a low ridge line that you've mentioned you might need more support of the rafters. It's hard to really tell without doing a drawing and figuring out all the roof loads.

A footing around the outside could work but the points where the posts sit on this foundation will have to be bigger and possibly re-enforced with re-bar.

In cutting off ends of beams, which are the deepest cuts that you will most likely have to make, you can do this with a standard skill saw.
To do this you just follow the steps spelled out in "Using layout tools" under the "list of timber framing layout tools" thread. Once you have your end of beam cut line drawn all the way around your timber then you cut the first face with the skill saw set at its full depth of cut. Then roll your timber over and cut the next face, continue this process until you do all four sides, then finish the center of the beam with a hand saw.
Other cuts into large beams can be done with a standard skill saw, and if the cut needs to be deeper than what the skill saw will cut you'll need to finish the cut to depth with your hand saw.

You'll be surprised at how fast a good sharp hand saw will cut a timber.

You don't need to buy a chain mortiser if you don't want to.
It can be done with standard woodworking tools.
A simple boring machine and bit can be purchased for around $200.
You can do it with your current power drill, and bits, if your careful and bore your holes correctly. Jigs and other things can be made to help you line up everything so it's done right.


As to your question about dropping a size down to 6x6, you haven't really stated clearly where you intend to use these 6x6's. If you're intending to use them as plates for holding up the rafters then the entire math needs to be done to figure the roof loads and spacing.
It's very hard to give a good answer without "all" the details which a drawing would provide.

You asked about securing the ties between the bents as you stand up a bent using your forklift.
I've seen it done two ways.
First if you're planning on continuing in timber framing you could purchase for this raising and future raisings, some straps and come-a-longs. Then after you raise an "H" shaped bent, and brace it off with temporary braces, you insert your connecting girts (beams going from bent to bent), into the first standing bent. Then you attach a strap to the top of "H" and another to the girt out near the second end. In between these two straps you connect them with a come-a-long. This will hold or "hang" the girt there until the second bent is raised and these connecting girt tenons are inserted into the second bent.
Some connecting girt may require braces. If so sometimes these braces are all that is needed to support the girt. This all depends on the design and plan drawing.

The other way to do it, instead of buying or using straps and come-a-longs, is to do it with lumber.
Once you have the first bent up and temporarily braced off, and you've inserted your connecting girt (with or without brace) you place two pieces of framing lumber (such as 2x8 or 2x10s) next to the far end of this girt. Place one on the inside and one on the outside. Next climb up a ladder and nail a cleat of wood across under the girt from one 2by to the other. This cleat should be nailed on using duplex nails and should be large enough to hold the weight of the piece. It could be a 2by4 or 2by6. When nailing this on to the two uprights, place it ¾" lower than the bottom side finish height of the girt.
This cleat is nailed onto these two supporting planks and it kind of looks like the rung of a ladder. Therefore this assembly is known as a support ladder.
As the second bent is being raised and hinged into place a helper can stand on a regular ladder and have his shoulder under the connecting girt and guide it into its mortise as the bent is hinging into place. This helper should only have to lift the girt ¾" to insert it, and most of the weight will be on the other end any brace, and the support ladder.
Once the second bent is up, and secured off, this support ladder can be disassembled and removed or moved to the next location for the next bent.
Another way it could be done is to just have men on staging holding up the girt. But this isn't the best.
It could be blocked up on staging if you have some staging, and blocking.
But a simple support ladder works just as well and you might need your staging somewhere else. And also, it's harder to move the staging once a beam is threw it.

My advice to you is to have a drawing made. Even if it's one you make yourself. Then have someone review it to make sure it's correct for loads.
It doesn't make sense to use 8x8s if you only need 6x6s, does it?
It doesn't make sense to use 6x6s if you need 8x8s.
You have to plan every detail out first, in order to make it a safe building.

Go to every raising you can.
Have fun and keep asking questions.
Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

JoeyLowe

Thanks for the responses.  Naturally, your answers have raised more questions in my mind.  Here is some additional information about my project.

The shop addition is strictly for my cabinet shop.  No vehicles will ever be driven into or onto the floor.  I prefer a wood floor since it is easier on the legs when working over equipment and benches all day.  The addition will contain a small CNC machine, a cabinet saw, planer and joiner and sheet stock. The largest footprint will weigh around 1000 lbs.  I can pour a slab if I have to, but I prefer not to.  Concrete around here is around $175/cyard and that would get pretty expensive pretty quick.

The bay doors will be of the 8' wide variety and will be overhead doors.  I'm not limited to a low ridge, but I prefer not to involve the planning commission since a few members prefer "extra grease" to get permits processed.  I can relocate windows as much as 2 feet higher without any major structural changes.

Thanks for the tips on the used home depot tools.  I'll check into that.  I especially appreciate the clarification of the girts. and how to support them.  Well, here goes with some more questions.

Regarding the drawings, I know anything worthwhile ain't cheap, but I have a hard time believing that it takes 30-40 hours to produce a simple drawing for a rectangluar single story building frame.  Am I missing something, cause at $150.00 per hour, that drawing is going to be worth gold when done.

Don't get me wrong, I prefer to work from a drawing and lord knows I've built plenty of buildings in the past. I guess the concept of timberframing seems so simple that I'm probably oversimplifying the process.  Are their any recommendations of who to use to produce a working drawing for me?  All I really need is the framework ( beam location, beam sizes, etc.)

I'm located in NE Texas.  Are there any good referral sources for locating "raisings" in my area? The Guild magazine never shows any in my area, except the annual workshop in April of each year.

Lastly, knowing what I know about structures, I could probably get by with all 6 x 6's in the construction, but I prefer the uprights to be 8 x 8's since I like their massive size.  I was concerned whether or not the "girts" had to be the same size as the bents or if the could be smaller.  Any help will be greatly appreciated.
--
Joey Lowe

"Working towards perfection has to be a part of anything one does.  You've got to put yourself into it." ... Sam Maloof (chairmaker)

Jim_Rogers

Creating a drawing of a 30' x 50' timber frame could cost that much. It depends on what level the drawing is going to be.
I would imagine a drawing of that price would include the structural analysis and be stamped with an engineer's stamp, and be presentable for building permits.
Is this what you're going to need in order to get a building permit?
Do your building department inspectors understand timber framing?
Some that don't want everything stamped, including plans and the lumber.
Careful research could provide you with the answers you need. And to understand what you'll need to have in order to get your building permit.

You stated you have cut timbers for timber framers. You've stated you've watched joinery being cut. Who are these people? Are they friends of yours?
Can they help you?
Who do they get to draw their frames?
Whoever they are, they could be familiar with timber framing and/or code rules for your area.
I'd try asking them first.
If they're too busy to help you then you could go outside of Texas to get help.

What type of wind load requirements are needed in your area?
I would imagine there is very little if any snow load? Is there a snow load requirement for your area?
What type of roofing are you going to use? Metal? Shingles?
Are you going to use plywood for the roof decking? Are you going to use your own 1" boards?
Is there any earth quake requirements?
Every detail has to be worked out in advance in order to figure out how much this roof will weigh so you can figure the size of the timbers?
You can build by guessing but when the building department inspector says it isn't right and you have to take it down, how much will that cost you?

There are timber framers in Texas; you can go to the Timber Framer Guild (TFG) website, at //www.tfguild.org, and click on the "resource guide". Follow the links to the guide and select find companies. Enter Timber framing company and TX in the fields and you should get a list of companies registered with the guild in TX. Send them an email and find out when they are having a raising and go and see one put up.

Try to figure out some of the things you'll need, and keep asking questions.

Good luck with your research and I'll send you a private message.
Jim Rogers

PS. Being a member of the guild you can go to the members only section and access the guild directory. There you can enter the state name and get a list of all timber framers in your state.
You could see who is close to you and ask them for help or advice about making plans or seeing a raising.
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

JoeyLowe

Hi all!  Sorry for the all of the inquiries.  The timber framers that I have cut for come from all over Texas, Arkansas, and northern Louisana.  Most are pretty busy and while some would entertain my questions, I calculate that all would also want to be compensated for my taking up their time.  I don't think it would be difficult to get anyone of them to build the addition for me, but this is something that I really want to do.  I took this property out of an estate sale some 6 years ago when it was worth less than $45k and renovated both the main house and outbuildings.  My latest and last renovation on this property will be the shop.  (I'm getting old and tired ;D)

There are no snow load requirements, but there are some wind load requirements.  I plan to use plywood for the roof decking along with asphalt shingles to match the rest of the existing building.  I've given some long though to the foundation today and am now leaning more towards just having slab poured.  I've also thought about using trusses for the roof.

The code inspector is not familiar with timber framing but is very familiar with my work so getting a permit shouldn't pose a real problem.  He seems to be more worried about electrical fires.  While stamped plans would be good for insurance purposes, they aren't necessary.

Jim, I got your private message and would like to discuss this further.  
--
Joey Lowe

"Working towards perfection has to be a part of anything one does.  You've got to put yourself into it." ... Sam Maloof (chairmaker)

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