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Doug Fir - Green or Dry??

Started by Rgates, April 05, 2008, 08:36:14 AM

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Rgates

Hello, Iam new to the site by way of posts but I have been lurking around for quite some time. I am in the process of ordering the timber, which will be FOHC Doug Fir, for my frame. The great debate is Green vs. Traditional KD vs. RFKD. In concert with that decision comes the lumber grade decision, ie. #1 or dense select structural. Any information with regards to the green versus dry would be greatly appreciated.

Frame inormation is as follows. The site is in Maryland. The house is 5500 sq. ft. and is completely timber frame except for the garage. The main roof is a hip with a few gable dormers and turrets. The roof will be 2x6 T&G. I am still debating the use of sips on the roof versus a built up system. The 2nd floor system will be on 1x6 T&G fir with a standard 2x4 floor joist system on top. The exterior walls will be 2x4 with spray foam insulation.

I am in the process of selecting the material for the frame. I have received a crash course on Doug Fir in the last 2 weeks. The only problem is that the teachers are the sales people, that are attempting to get you to buy there product. In light of that I figure that this would be an excellent place to get an unbiased opinion.I think that about sums it up. If further elaboration is needed I will be more than happy to comply. I could write a novel with regards to this project but this is not the place for that.

Thanks

Don P

Sure it is  ;D Now that we have you out of the shadows its time for details, got any pics of the project?

I would use dry materials if at all possible. Do I care how my clothes got dry, not especially. As long as the quality of the dried product is the same and to the same level I'd use the cheaper supplier. I would write acceptable moisture content into the purchase documents after coming to an agreement with the supplier.

Grade is first dependent on design minimum strength requirements. After that it will have "better" appearance as you move up through the grades.

Rgates

Thanks for the reply Don. I have a lot of visions, but no pictures as of yet. I realize that the dry material is better to start with but the real debate is with regards to the upcharge for the dry material. In my case it is 20k more. Is it worth the 20K or do I go with a dense select structural green material and save the 20K. I have heard arguments both ways from the sales regime. I am hoping for some unbiased input.

Thanks

Ron

Don P

I'm not sure I'm following, the shrinkage green to dry is going to be about the same in dense SS as in #1 or 2.

Rgates

Sorry for the confusion Don. If I would go with the green material I would up the grade to Dense Select Structural(DSS) . If I go dry I would drop to a #1. The green advocates claim that the DSS, because of its higher quality fiber, will behave just as well as the #1 conventional KD dried product ( 19% Moisture at 1" from surface). The green advocates claim the conventional KD will not make that much difference in shrinkage because it is only dry to 19% at 1". The RFKD is an entirely different scenario( approximately 15% at the core). Naturally the latter commands the highest price. I am hoping that someone here has been through this scenario and can shed some unbiased light on this decision.

Don P

The wood will behave pretty much the same while drying regardless of grade, that is really another decision. I'm not going to tell you Dense SS will perform as well as partially dried of another grade, I doubt it will. Density in a species like Dougfir if anything is going to cause greater shrinkage than a less dense stick, all else being equal. Wood substance is what shrinks, not air, denser woods tend to shrink more. On this scale I doubt it'll make much difference I'm just giving another viewpoint from the salesman's logic.

It mostly revolves around what you consider acceptable and a fair balance. The house frame will function well enough if built from green materials. There will be more gapping and distortion than if it were built from dry. If that seems like a fair trade then go with green. If you are the type of person who wants to see the joinery remain as tight as possible even if it costs a premium then buy dry material. It might be worth pricing reclaimed material too.

In milled log construction I've worked with about every moisture content. Customer satisfaction or lack thereof was pretty closely tied to moisture content and expectations. Judging from the size and your description of the project I don't think you'll be happy with green materials but hey, I met you 2 posts ago  :).

BandsawWarrior

Kiln dried or not the wood is still going to shrink and check.  We sell mostly green fir timbers for house packages.  And if you're getting all FOHC that will be pretty stable stuff.  I'd save the 20k

Fir is my favorite wood in timber frames great choice!

that's my 2 cents!

Tyler Hart
T&N Custom Sawmill

kderby

Hi  Ron,

Disclaimer: I am one of the people who want to sell you logs.

My take on your question: Part of what you get when you hire a skilled designer/builder in the realm of timber frame is a person who knows the wood is going to move and operates accordingly.  The degree of movement is less on a dry log but it will still move.  I am not a framer but have been around a couple of projects where log or movement was designed for and accomodated.

Thus I tend to argue for the green timbers.  The bad news is that you will be paying to transport the water within them.  Look for mechanisms to reduce the degree of movement and the weight of the timbers.  That would be salvaged material or the standing dead fire killed material we talked about.

Cheers

KD

matt eddy

from a shop point of view:  I prefer green Fir.  Spend the money however on a higher grade.  Dry fir can be a pain to work, however it is possible.  I have used both, if you are going with dry, I have gotten some real quality reclaimed fir.  I live on east coast so I try to stay away from fir, but i did a recent job in Alaska that was fir.  It sat around for a yr before I cut it, and as a result it was hard on tools.  When using fir I sharpen my chisels and mortiser chains at a steeper pitch.  this seems to cut better through it, and the edge lasts longer.  Fir also can be stringy!  Good luck with project!
Matt

Rgates

Hi, sorry for the response delay, was out of town. I have looked at several types of Doug Fir with prices from one end of the spectrum to the other. In order of least to the most expensive here is the list, (note that grading and type of cut further increases the complexity and can easily change the cost structure order).

Green, FSC, standing dead, KD, RFKD, and reclaimed.

I will admit that I was intrigued by the reclaimed until I got the price. WOOOW,  it was 3-4 times the cost of virgin timber. Once I got up off of the floor and restarted my heart I realised the reality of reclaimed was but a distant dream. Conservation at those costs is a hard sell, at least for me. I have spoke to small and very large suppliers, each having there own approach to my material selection. It has been an experience to say the least. I appreciate all of the input that I have received here.

Ron


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