Oak timber frame

jeff... · 03-09-2008, 09:23 PM

Was having a discussion with a fellow about timber framing a house out of Oak. Timers are going to be 8x12 at least the ones I'll be cutting. He asked my opinion about joining timbers together... I expressed to him that you can't just drive a nail in that stuff and expect it to stay put. I mean it's going to need to be bolted and plated and shrinkage will need to be calculated. The timbers are going to draw up when they dry it may take several years for something that big to air dry.

He agreed but disagreed when I expressed my view point about how I thought the fasteners would need to be galvanized, powder coated or heavily painted. With all the acid in green oak, I'm thinking the acid would weaken any non-treated steel fastener. At the very least leave a very unattractive blue'ing where the green oak touches bare steel.

I know from first hand experience what green oak does to bare steel. Any steel green oak touches turns black and the oak turns blue. Yeah bleach works pretty well to clean up the blue in the wood but you have to bleach entire piece else it looks like (four letter word of your choice). Spotting tramp metal in Oak logs is easy, it leave a very visible blue streak.

Anyways it's his house, I'm just going to be cutting some of the timbers. Maybe I should learn to keep my shut. But he did ask for my opinion and I gave it to him... guess he didn't like it much... I was wondering if someone may have ****ed in his Cheerios ???

Am I wrong in my understanding of bare metal fasteners and green Oak?

Thanks

Gotcha6 · 03-09-2008, 09:51 PM

You are not wrong. I'd use hot dipped galvanized bolts & plates at the least. Most timbers I've seen this size are M & T and pegged with oak dowels. As for shrinkage, when I tried to sell log homes, they designed their packages to allow for 1/8" per foot of cross grain shrinkage. Lengthwise I don't know about. You'd also be wise to avoid any sloped grain logs to avoid twisting as it dries. If the customer insists, I'd have them sign a 'hold harmless' waiver.
People that know the difference between good & bad advice don't need it.
Those that don't - won't heed it.

wayne · 03-09-2008, 10:04 PM

A true timber frame structure does'nt use metal fastners they are put together with pegs and joinery. If he is building a true timber frame structure he has his work cut out for him in both the cutting of the joints and then the raising of the bents. Tedd benson a modern day timber framer has some very informative books on the subject. He should communicate with his local building inspections office before getting to involved in the venture.
It would be the ideal excuse for a great gathering, just like the old barn raisings of the old days.

jeff... · 03-09-2008, 10:24 PM

Originally Posted by Gotcha6

You are not wrong. I'd use hot dipped galvanized bolts & plates at the least. Most timbers I've seen this size are M & T and pegged with oak dowels. As for shrinkage, when I tried to sell log homes, they designed their packages to allow for 1/8" per foot of cross grain shrinkage. Lengthwise I don't know about. You'd also be wise to avoid any sloped grain logs to avoid twisting as it dries. If the customer insists, I'd have them sign a 'hold harmless' waiver.
People that know the difference between good & bad advice don't need it.
Those that don't - won't heed it.

I don't think the guy would know what a pegged mortise and tendon is. I mentioned it, he looked at me like I was dumb or something then told me he was set on steel plates... so that's were the conversation went. Anyways I'm washing my hands of any further conversation, I'll cut his logs but that's all I'm going to do. Some people just don't want to hear what others think, unless it agrees with what they already think. People like that should not ask for anyone else's opinion... they really didn't want to hear it anyways...

Thanks

NCPete · 03-09-2008, 10:28 PM

Jeff... just re-affirming the importance of that "hold harmless" waiver that Dennis mentioned.

wayne · 03-09-2008, 10:32 PM

Originally Posted by jeff...

I don't think the guy would know what a pegged mortise and tendon is. I mentioned it, he looked at me like I was dumb or something then told me he was set on steel plates... so that's were the conversation went. Anyways I'm washing my hands of any further conversation, I'll cut his logs but that's all I'm going to do. Some people just don't want to hear what others think, unless it agrees with what they already think. People like that should not ask for anyone else's opinion... they really didn't want to hear it anyways...

Thanks

He apparently does'nt know or understand the differance between timber-frame and post and beam construction.

jeff... · 03-09-2008, 10:32 PM

Originally Posted by NCPete

Jeff... just re-affirming the importance of that "hold harmless" waiver that Dennis mentioned.

What's a "hold harmless" waiver? Guess I need to Google...

NCPete · 03-09-2008, 10:34 PM

exactly that he declines the opportunity to hold you responsible for any defects to his construction with the material you provide.

erasmussen · 03-09-2008, 10:42 PM

I really hate it when someone asks for your opinion then dont want to hear it, wants to argue, or are just to dumb to understand what you tell them

jeff... · 03-09-2008, 10:43 PM

Originally Posted by NCPete

exactly that he declines the opportunity to hold you responsible for any defects to his construction with the material you provide.

Do you have a good fill in the blank one? I will most defiantly have him sign before I put of fork to his logs, let alone a blade...

Wondering if it must be notarized here in NC - seems most things work that way here... Oh well just another opportunity to get the mayor's autograph...

Thanks

NCPete · 03-09-2008, 11:47 PM

not sure I do... I may have one in a stash of legal forms buried somewhere on this computer... but they were poorly organised in one multi-page Word file, but may have deleted it out of frustration.

AdamO · 03-10-2008, 09:52 AM

I just got through using some Douglas Fir 8x12 beams in my house. There was a good bit of engineering involved in getting everything to shake out. I don't know how much I'd worry about fasteners and jointing for this guy. If your guy is going to use the beams in his house, I don't see how he can avoid getting an engineer involved to get it through the building inspection folks. He will probably have to get everything graded or pay an engineer to sign off on the lumber grade while he's signing off on everything else. If it's a barn or other outbuilding, he can probably screw it up to his hearts content without much oversight.

If you want to get him to sign something, you might consider including something that indicates that the timbers are not graded and that you make no representation as to their structural capacity.

Good luck.

walnutjerry · 03-10-2008, 01:35 PM

Why not white oak pegs? That is the way it was done in early times and there are plenty of that type construction still standing. No rust for sure. If you have ever dismantled a structure put together that way you will have an idea of how strong it is.

Jerry

Gotcha6 · 03-10-2008, 01:36 PM

I doubt you need to get the H-H doc notarized, but a witness is a good idea. It should just say what you've been told here about the limits of your warrantability and responsibility as to suitability for his specific needs, grading, shrinkage claims, etc. (gee, I made that sound like Jesse Jackson). Just CYA with someone like that.

FredP · 03-10-2008, 02:21 PM

um I think all lumber to be used for a dwelling [ house ] has to be grade stamped. he prolly is gonna have a hard time with the inspection dept. oh well cut the timber and cash the check!

a waiver would be helpfull for your protection. you may want to have a lawyer advise just in case. no need gettin sued for his ignorance.

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