I live in the south and have yellow pine on my land that I would like to use to build a timber frame home. I keep reading how yellow pine will twist and shrink a lot. So, what would be the best practice to minimize those issue. Should I cut the trees needed and leave them whole for drying then mill into lumber sizes needed, or just mill the trees down to size and stack to dry for 6-12 months? Thank for any input as I am just in the beginning stages of the adventure.
The most twist is in a timber that has about 18 rings and has the pith centered. At 30 tings, there is little twist...actually the spiral reverses so it cancels out the early spiral in the other direction.
You should, at the least, remove the bark and treat the wood with a fungicide intended for wood and the blue stain fungus. Drying the log and then cutting the timber will help reduce twist, but is seldom done due to stain and long drying time and cracking.
Normally we cut about twenty percent more long framing pieces and then dry. The 20% that twist too much are then cut into shorter pieces.
What Gene said.
We milled out some 35' SYP last year for a contemporary home. Milled at 7" x 14" green with the intent of finishing at 5-1/2" x 12" dry and straightened. Milled lengths were between 32 - 35' for finished lengths of 26' - 31'.
Of 24 beams milled, 4 twisted too much to use. The rest we were able to straighten with the swingblade sawmill
(https://forestryforum.com/gallery/albums/userpics/13296/Beams_in_kiln_at_end_of_drying_cycle~0.jpg?easyrotate_cache=1598635785)
18 of the timbers met grade stamping requirements from SPIB. The ones that failed were milled from logs that had heavy vines growing on the outside, and there was some porosity in parts of the beams.
Here is what they looked like after planing and end millwork.
(https://forestryforum.com/gallery/albums/userpics/13296/IMG_1398.JPG?easyrotate_cache=1598636507)
The kiln run in the Nyle was around 90 days.
Thanks for the info, I am just in the planning stages but do know I will have enough time to have trees taken down a year before needed. Then as Gene said debark and spray. But is that enough time for drying before milling down to rough sizes. Also, was not planning on kiln drying this as well does that cause another problem I should be looking into as well. Thanks again for the reply's
If you fell the logs in fall or early winter, it will stain less.
It seems to me that you have a trade off between twist and drying. If you leave the logs to age in In order to reduce twist, when you mill them they will have a higher mc% inside.
If you mill them green, they will dry more quickly but you're left with the potential twist.
Personally I would mill them 20% oversized with 20% or more extra quantity, sticker them and let them dry for a year under a shelter. At the end of the time remill them to final dimensions.
Thanks your help is greatly appreciated. Now onto the next issues which I am sure will be many.
In much of the commercial drying of pine, they use temperatures over 220 F. At these temperatures, the wood is pliable, so that with excellent stacking procedures, the ones that want to twist can be held somewhat flatter. I did see in Australia, where they made the stacking cart so that it was not flat but had twist in the opposite direction that the pieces twist. (All pines twist one direction, the same direction, the first 15-18 years and the. Reverse slowly after that.)