The Forestry Forum

General Forestry => Timber Framing/Log construction => Topic started by: francismilker on March 10, 2023, 08:07:17 PM

Title: Post Oak Beams
Post by: francismilker on March 10, 2023, 08:07:17 PM
I'm sure this has been asked many times in multiple threads, but has anyone used green sawed post oak for barn beams and posts? 
Right now the post holes are all dug and there's concrete sonna tubes above ground 6" to avoid ground contact. 
Just wondering about the longevity of it. 
Have used it before with mixed results for small sheds and projects that were not "important " and involved so much time, effort, and money. 
Planned on using 8x8 uprights for posts on 10' centers and 8x10 beams on top of the posts. Then, perpendicular to that using 2x6's on edge for lathes to attach sheet metal to. 
My experience with post oak is that if I cut it and screw/pin it together asap it's pretty forgiving to work with but if I wait a few days it's rock hard and has to be pre-drilled. 
I expect some shrinkage and possible twisting, but it can't be any worse than todays PT lumber coming from the big box stores. 

Just wondering about the longevity of using post oak. All lumber will be covered with sheet iron or ERC. 

Thanks in advance. 
Title: Re: Post Oak Beams
Post by: Don P on March 12, 2023, 08:33:51 AM
For sizing things it falls into the "mixed oak" group in the calcs.
I have no experience with it, knowingly :D. I borate oak to keep the bugs down. With battery tools I predrill just about everything anyway.


edit to add.
just rocking back and thumbing through looking for honey locust and post oak popped up again, it also falls under the white oak species group in the NDS tables. That will probably give you better allowable spans than the mixed oak group.

The listed white oaks there are;
Bur, Chestnut, Live, Overcup, Post, Swamp Chestnut, Swamp White, White.
Title: Re: Post Oak Beams
Post by: Den-Den on March 13, 2023, 05:24:19 PM
Post oak is very weather resistant and strong.  It takes what seems like forever to dry.  I have seen straight trees produce straight beams but would not count on that, it is likely to warp and twist badly.
Title: Re: Post Oak Beams
Post by: Tom King on March 13, 2023, 06:18:14 PM
I always wondered where the name came from.
Title: Re: Post Oak Beams
Post by: Magicman on March 13, 2023, 07:25:54 PM
I would suppose because they make long lasting fence posts.  The longest lasting of the White Oak species.
Title: Re: Post Oak Beams
Post by: Tom King on March 13, 2023, 07:34:19 PM
That had always been my guess, but I didn't know until now.
Title: Re: Post Oak Beams
Post by: Magicman on March 13, 2023, 07:36:29 PM
I said "suppose" so maybe I'm guessing.  ;D   LINK (https://www.wood-database.com/post-oak/)
Title: Re: Post Oak Beams
Post by: Tom King on March 14, 2023, 04:04:47 PM
Some interesting comments in that link.  

Also found this.  I don't know that we have a single tree on our place.

Quercus stellata Wangenh (https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/quercus/stellata.htm)
Title: Re: Post Oak Beams
Post by: Magicman on March 14, 2023, 04:13:05 PM
Which could easily be.  It all depends upon whether there are "mother" trees to supply the seed acorns.  My farm property is 46 miles West of where I live and there are no Post Oak trees on that property.  There are many here.
Title: Re: Post Oak Beams
Post by: francismilker on March 14, 2023, 08:40:01 PM
Thanks for all the input everyone!

Magicman, you can pull your mill to SE Oklahoma and cut up all the post oaks you need from my place! That and pith-elm are the predominant species around here as well as lots of invasive ERC taking over peanut land that hasn't been planted in 30 years.