Air drying Oak flooring

[forest keeper]

Well I'm sure that this topic has been discussed before, and I have read through some previous posts on the topic. Generally speaking, how long should it take a stickered stack of 1" Oak boards to air dry? We have had a few stacks of wood that we intend to use as flooring,  out in the open for about a year. Surprisingly little checking. Do I have to worry about kiln drying at this point?

[pineywoods]

Flooring for what or where. If you are talking indoor floor, definitely kiln dry, else it will shrink badly. Kiln dried flooring installed in an outdoor environment will swell and buckle. For air drying, figure a year for each inch of thickness.

[DRB]

I always recommend kiln drying for flooring. The kiln adds so much to the stability of the wood.  If you do not kiln dry I recommend about 2 years of air drying then stack it inside the heated room to be used in for a couple months with stickers.  Regardless what you do it will not be as good as kiln drying.  Not to say you can not make air dried flooring just that you better expect a fair amount of instabilty and shrinkage compared to kiln dried.   

[kelLOGg]

It also depends on your geographical area. The following table shows equilibrium moisture content at various humidities. If you live in a dry enough area air drying may suffice. Generally 6 - 9% EMC is OK for indoor flooring. If you can't achieve this level by air drying you will have to kiln dry or you will get large gaps or even cracks. You can reduce the size of the cracks by cutting the flooring narrow.

Table 1. EMCs at Different Humidities for 30 to 90°F
RH     10    20    30    40    50       60        70      80        90
EMC  2-3    4      6    7-8   9-10  10-11  12-13  15-16  10-21

[Den Socling]

And don't forget the bugs. Kiln drying will kill the critters.