|Home » Forums » Sawing and Drying Forum » Message||Login|
You are not logged in. Consider these WOODWEB Member advantages:
DH kiln drying douglas fir beams and posts7/17
I am purchasing a Nyle DH 200 kiln. I am interested in kin drying Douglas fir beams as large as 8"x24"x33'. Once the beam is air dried to about 30% is it feasible to kiln dry in a DH kiln? If not, what is the largest beam I can dry. I am also a licensed general contractor as use beams for structural purposes. I will receive my new kiln in a week and am trying to decide how large to build the kiln. I helped my father build several houses using 4x12 beams with 2x6 T&G decking in the 80's. I material was only air dried and sometimes twisted at the ends ripping out 1/2" lag bolts which attached 4"x10" 3/8" thick steel plates. I would like to avoid this problem. Thanks for your insight.
I hope you studied this out prior to such a large purchase.....Large beams aren't feasible to get KD to standard building lumber specs.....time and time are against you.
From all the reading I've done a true KD beam to the middle for a log home log would take 6 months to properly dry. Most that claim KD'd are removing some moisture BUT are mostly using the Sterilization of the process.
Gene may correct me due to he keeps up with the industry in drying. I'm only going with past research.
Even to AD that size beam completely would require several years.
I think the only ones that have true dried in depth beams start with standing dead timber.
Most but not all timber frame and logs in those type homes are not dried completely AND have to be built with that in mind for future movement. Yes lag bolts can be ripped out like toothpicks. Through bolts are stronger BUT harder to hide the threaded parts.
To add: If the beams with your dad had been fully AD'd the twist shouldn't have happened normally. IF AD'd properly the advantage is normally it relieves the stresses that cause the twisting.
Next...kiln size....that is a long kiln....did Nyle spec this unit or did you. It seems that the area will need to be fairly large to process enough at a time and I'm not sure how large of cu. ft. that unit will sterilize properly when that long. I would definitely think extra fans needed.
The better/tighter you can insulate the better the unit will work.