MC-12
MC-12 is our standard that indicates the wood's moisture content will be dried to 10-12% Moisture Content (MC). This is most applicable to softwood lumber and slabs. As a point of reference, here in Western Washington, lumber that will be outdoors but protected from rain water, will have an equilibrium MC of about 12%. This means that even if we dry your wood to 8% MC, it will return to 12% in a matter of months.
MC-8
MC-8 is our standard for wood that needs to be 6-8% Moisture Content (MC). This is most applicable to softwood and hardwood lumber and slabs that is intended to live indoors in heated spaces. Equilibrium for indoor wood is about 8% MC. So for furniture, flooring, interior siding, or anything that includes wood joints, it is recommended that the wood is dried to MC-8.
HT
Heat Treatment (HT) is an optional process of treating wood with higher temperatures of 150 to160 deg. (F) for a period of 24 hours. HT is used to set the pitch in pitchy softwood. HT is also effective to kill your wood's worms, termites, beetles or mold, where raising the temperature to over 133 degrees for three hours is proven effective. This is an optional process, so be sure to ask about it if you need it.
KD
Kiln Dried (KD) is an industry standard for which most construction framing lumber is dried to. KD designation means the lumber is better than 19% Moisture Content (MC). We actually dry very little lumber to this standard.