"Emergency" drying

[kelLOGg]

I have a customer whose son is in town for several weeks to build her an artist studio. She has bought all the KDed and sterilized SYP I have and needs more. I have more air dried SYP and since there may not be enough time to KD it, is it wise to put the air dried lumber in the kiln and sterilize it? or it too much risk of splitting?

[kelLOGg]

I think I can according to Diagonal sheathing drying and sterilizing in Drying and Processing (forestryforum.com)

but I don't know if the poster was using SYP. 
Comments still needed.

[doc henderson]

is this for framing?  what is the MC of the air dried lumber?  @GeneWengert-WoodDoc 

[kelLOGg]

B and B siding 12%

[WDH]

I did it once and it was a heck of a sauna.  

[Southside]

Am I reading this wrong?  Your lumber is 12% right now, and it won't get any drier without a kiln this time of year.  It's well into the safe zone and being SYP you can push it hard.  Should not take more than a few days to finish it off and HT at the end.  

[YellowHammer]

I agree, sterilizing moist wood will drive the humidity up can cause a sauna, and a lot of your electrical energy to sterilize will go into heating the water in the air.  

I'd take a day or two and dry down to 8% and use that time for the compressor to naturally bring the temps ups to 120 and then just get the extra 30 degrees with the strips.  

[kelLOGg]

Taking the MC down first seems to be the consensus of opinion. I will check with the customer and see if the schedule works for him. Thanks.

[GeneWengert-WoodDoc]

The sterilizing cycle also evaporates some pitch.  But at 12% MC, any insects that like moist wood will find 12% attractive, so insisting on sterilized wood, which is only sterilized for the moment and not forever, or even the next day, is a waste of time.  Insects in 12% MC SYP are rare;that is, many insects want even wetter wood.  The old house borer is one that likes drier, but not too dry, wood.  The termite is another.

[kelLOGg]

The sterilizing cycle also evaporates some pitch.  But at 12% MC, any insects that like moist wood will find 12% attractive, so insisting on sterilized wood, which is only sterilized for the moment and not forever, or even the next day, is a waste of time.  Insects in 12% MC SYP are rare.

: 12% is attractive to insects yet insects in 12% are rare?
??? So, why does anyone ever sterilize if it doesn't last even a day?

BTW, customer is taking another route and doesn't need more KDed SYP.

[Don P]

Lyctid ppb's like dry wood, but they prefer hardwoods. Sterilizing kills whatever is already in the wood but does not offer any protection from future attack, it is one prong of the preservation strategy. With pine the kiln can also set pitch which is a good thing.

[mike_belben]

The sterilizing cycle also evaporates some pitch.  But at 12% MC, any insects that like moist wood will find 12% attractive, so insisting on sterilized wood, which is only sterilized for the moment and not forever, or even the next day, is a waste of time.  Insects in 12% MC SYP are rare.

: 12% is attractive to insects yet insects in 12% are rare?
??? So, why does anyone ever sterilize if it doesn't last even a day?

BTW, customer is taking another route and doesn't need more KDed SYP.

I think gene meant to type unattractive. 

[GeneWengert-WoodDoc]

Insects need a source of moisture, so wood under 12% MC has so little moisture that most insects cannot survive.  At 12% MC and wetter, there is enough water.  Further, the insects need to be able to "bite off" little chunks of wood.  At 12% MC and above, the wood is easier to bite off.

The sterilization only kills insects that exist at the moment, but provides no lasting protection.  Hence, with 12% MC and wetter, the wood is attractive to some insects.  Others will find that the 12% MC wood is still too dry.  However, framing in a house Walli can easily be higher than 12% MC around plumbing, when vapor barriers and/or insulation are not used or functioning, poor drainage of rain water, or outside humidity is high.  For example, in the summer, it is not unusual to see condensation on the outside of a window due to cooling from the interior air conditioning.

The reason for sterilization is to kill insects that can damage or kill a tree.  The idea is that these insects will not attack lumber but only wood in a tree.  The big concern is insects at the wood and bark intersection region.

[customsawyer]

For b&b siding I would just use air dried and let it go. It won't stay below 12% very long and any sterilization will be a mute point after it's installed. You can also use green off the mill for B&B as any shrinking will be covered by the batten strip.