Kiln dried beams

[Crossroads]

There are a few contractors in my area that refuse to use any beam unless they have a KD stamp on them. Are these beams really dry? What kind of a process/timeframe would it take to actually dry an 8x8 Douglas fir beam? 

[Ianab]

Vacuum kiln? Big $$. 
or 
Air dried for a year or so, then put through a sterilise cycle so they can earn their stamp? 

KD for construction softwood only needs to be under 20%, and that's achievable given a bit of time.  Is it fully dry? Probably not, but it's below the moisture level that causes problems with rot etc. 

[Brad_bb]

By contractor what do you mean, a rough stick framer?  Why would they be using a doug fir beam?  Is it structural?  Is it non-structural for looks?

Timber framers usually use green timbers.  Rough stick framers don't normally use them and hence are very cautious/fearful because they are not familiar with how to handle them.  If you use metal fasteners like nails or screws, they are likely to rust in green timber or rot the wood around the metal.  We prefer not to use metal fasteners because of this.  If you must, they must be hot dipped galvanized to protected sufficiently from corrosion.  

Don't have them do something they are not comfortable with.  Get someone who knows what they are doing.  Still not sure what you're trying to do.

[Crossroads]

For the most part, I'm just curious. I would say they are not "timber framers" , but general contractors who are doing some timber framing. I have milled for some guys that claim to be true timber framers and they weren't even slightly concerned about the beams not being kiln dried. 

I am considering building a bigger kiln in the near future. Trying to figure out if drying beams would be feasible or not. 

[Brad_bb]

I had some 3" thick walnut stair treads kiln dried and they were probably in the kiln for almost 3 months.  Most of them had been air drying for 1-2 years.  Anything thicker than 3 inches, forget it.  It's just not practical.  You're better off air drying beams for 1-2 years or more to get most of the movement out of them and then re-milling or jointing them as I do with a Woodmizer mill mounted planer/jointer.  Most people don't have that kind of time or space unless you're a homeowner with a mill and shed space preparing your own material for your project.  They aren't "dry" by then, but a decent amount of the movement is out and you'll have less in the conditioned space.

[Crossroads]

With my limited knowledge of kiln drying, what you're saying makes sense. To me it seems that kiln drying a 6x8 is more about getting the feel good stamp on it. On the other hand, I see the importance of heat treating the same beam to set the pitch. Having a beam ooz pitch all over expensive furniture would be all bad. 

[scsmith42]

I recall in one of Gene Wengert's classes he mentioned that green, doug fir only has a MC% of around 30%, and that they dried very easily.  That's why they were a popular choice for a lot of D log type of log cabins.

[Crossroads]

Next time I'm around one of their projects, I'll try to remember to bring my moisture meter and see what the mc is

[Don P]

Are you desiring to produce structural timbers?
There are 2 log/post and beam companies nearby. I've bought well dried EWP timbers from one of them several times. They are also graded. As a GC, if I can get dry and graded on a residential job it is generally not worth the time and risk in trying to get green ungraded through the hoops. For exempt structures, sure.

You just need a drying shed ;D;
Saving the Brooklyn Navy Yard's Timber Shed | Turnstile Tours

[Crossroads]

I'm pretty opportunistic and would definitely like to sell more beams. I'm in a position where I need to custom cut as I don't have the space to store a large assortment of precut beams. Even if I picked say 3 dimensions, I would have to cut each at full dimension and nominal. Then I would need to cut each of those 6 sizes at multiple lengths. So, I try to keep 6-10 mbf of logs on hand that I can cut to the lengths needed without wasting any. 

[Crossroads]

That's a big shed! I wish I even had that much flat ground to play with. Most of my property is hillside 

[Brad_bb]

I don't know anything about setting pitch as I only cut hardwoods.

[Stephen1]

An RF kiln is what is used to dry beams. Basically a giant Micro Wave that goes to 0 vacuum and then bounces radio waves along that beam to boil the water out of them. An expensive kiln. It will bring the wood down to 6-10%
I will put Fire place mantles and beams thru my kiln, but usually only for a 2 week cycle. It takes the moisture down to the 20% range and heats to 160F sterilizing the wood. 

[Don P]

The local log home guys are conventional steam and DH, they are not trying for interior furniture dry, they are hitting your range, down to ~15% from the one I've bought from... shed storage post kiln vs on to trucks and out of there from the other outfit, they would rather sell me the whole house. I'd bet both exit the kiln around 20% and the larger outfit keeps drying in the sheds depending on flow. I'll get closer to emc when times are slow. We got RF/V on one job, a company out of WV. too many brain cells ago, Sunwood?

[scsmith42]

The local log home guys are conventional steam and DH, they are not trying for interior furniture dry, they are hitting your range, down to ~15% from the one I've bought from... shed storage post kiln vs on to trucks and out of there from the other outfit, they would rather sell me the whole house. I'd bet both exit the kiln around 20% and the larger outfit keeps drying in the sheds depending on flow. I'll get closer to emc when times are slow. We got RF/V on one job, a company out of WV. too many brain cells ago, Sunwood?

I think that they closed up during the recession of 2008.

[cabindoc]

I have been working with log homes for 20 years.  Some KD, some don't.  In a log home kit, they usually provide log that are treated for the walls, stacked and then logs and square timbers rated for headers.  These are usually yellow pine whereas wall logs are usually EWP.  I make square and round logs and timbers every day.  sizes are 6x8, 6x6, 8x8 and 10x10 and in round it's 8" and 10"  10-12' typicall. I will put in the DH kiln (5-600 BF) and run it for weeks until MC is below 20, then do a sterilization. I cut 1" larger and strap down to cart to reduce twist, but they all go back on the mill to be cut to final dim.  I have used 10x10,s for building pavillion style structures with my products and no one asked me where was the grade stamp.  But, I get that some will.  Use your local forester, he may be able to grade.  Otherwise, check with Log homes and timber council. 

 https://www.nahb.org/nahb-community/councils/building-systems-councils/bsc-councils/log-and-timber-homes-council

Good luck

[Don P]

Hang with me, there are a couple of turns.
The building code most of us deal with is the residential code, some form of the IRC.

It is one element of each state's form of the IBC, the overall construction code. That code pretty much requires design by a licensed professional.

Recognizing that every residential house does not require reinventing the wheel, and thus does not require the services of a licensed design professional, the IRC was created as a prescriptive code. As long as you can follow the "prescriptions" in that book, the tables, charts and text, then you do not need to hire an architect or engineer to design and size the pieces. That code also says you only need design on those parts that are not prescriptive, not the whole house. Think about it, that is how trusses work, the truss shop does not engineer the house, just the trusses. I hand that paperwork to the BO (building official).

Somewhere around chapter 14 is a list of "referenced standards" recognized outside sources of approved methods. Use that stuff, show it to the BO if asked, and you are prescriptive as well.

For log homes, TF has been sitting on their backsides, for log homes, there is the "Standard on the design and Construction of Log Structures" Icc400-2007 ..  that is my version, the ICC bookstore will have the current version.

4th turn  :D
The tables of design values in there will probably help if it is a log structure... and sometimes if it is timber, especially in round or lightly flattened log beams because those timbers have significantly higher design values.

A forester is not a grader, nor is he insured for it. That is part of the reason behind requiring a grader, or that RDP if working in their area of expertise, is going to be covered by their insurance. That discussion of insurance pathways this morning kind of unclinched my tongue, but shows the "correct" path here I hope.

Off to do a sketchy boom over a decrepit farmhouse and hope it all works out. We do have to provide too.

[K-Guy]

With beams it takes to long to remove the core moisture to 8%, so most will dry it till the core is around 25% and then heat treat. It will average out between surface and core below 20% and will have done most of the shrinking. At that point it can finish drying after installation.

[Crossroads]

That makes sense

[WillisHomestead]

By contractor what do you mean, a rough stick framer?  Why would they be using a doug fir beam?  Is it structural?  Is it non-structural for looks?

Timber framers usually use green timbers.  Rough stick framers don't normally use them and hence are very cautious/fearful because they are not familiar with how to handle them.  If you use metal fasteners like nails or screws, they are likely to rust in green timber or rot the wood around the metal.  We prefer not to use metal fasteners because of this.  If you must, they must be hot dipped galvanized to protected sufficiently from corrosion.  

Don't have them do something they are not comfortable with.  Get someone who knows what they are doing.  Still not sure what you're trying to do.

Curious to what non0metal fastener do you use?

[Southside]

Don - was that boom over considered prescriptive?  :D

[Don P]

He was looking a little conscripted, it all worked out in the end ;D
All I can do is is tell em, never get out of the boat.



 



 

Times were tight, one wire heading to the springhouse to power it, ground on the pipe. This farm is too far gone to save, we're gentling the demise. A gentleman a little older than me was i think the last to grow up there.


 

[Southside]

We have one that is rougher than that, the last person to live in it was a freed slave.  There is no saving it, but I can't bring myself to bring the excavator to it either.  Never had indoor plumbing.  

[Stephen1]

I would think, wooden pegs, tenons into mortise joints

[Don P]

From what I could see it is braced frame, I'd call it the transition from a timberframe box frame towards a modern stick, or, platform frame. I had this in my gallery it is from a building magazine that was probably current with that construction, turn of the century. Copyright should be clear by half a century . Braced frame is on the right with full height pegged light posts and girts. but sort of box frame-ish thinking in my mind. This one has raising plates up top I'm sure. 4x6's, 4x4 window and door posts with 2x4 infill studs. The barn is TF. 

Balloon frame with all 2x is on the left in this pic. We are typically braced frame here. direct sided, unsheathed as you see there. 5/8x6 siding, nice carpenter details, he spent time on the trim when you look at that pic above and it looks good.




Hang on.. I've got a pic here that is a hoot. You know how purist say "Oh no you can't use steel with wood, it reacts and causes decay". Termite trails on the face of this, the pegs were the termite way into and out of the timbers. On all but 2 or 3. We'll never win  :D