How much will flat-sawn oak warp?

[Thomas Colson]

I’m a serial renovator, currently renovating my 2000 SF hand-hewn log cabin. I’m hoping to do all of the walls and ceiling with oak planks. I have a pile of 8 foot oak (red and black) logs that I’m about to have sawn. I’m interested in the greatest volume of cut lumber, not really interested in “furniture grade”, as this is a hand hewn cabin! I’m loosing sleep over whether I should get it quarter sawn, or flat sawn. The biggest log I have is 22 inches, some are 12, and I know you really can’t QS below 16. My question is, how much is flat sawn oak going to warp and cup in a cabin in East TN where sometimes it’s so humid you feel like you’re swimming? Bug holes, kerf marks, knots, don’t bother me but I loose my mind when I see drastically cupped, gapped, or warped boards. Is oak so unstable that I should give up on flat sawn? Is it going to cup, as sure as the sun comes up? I am going to have it kiln dried. Given the availablity of oak to me (not much left), I really can’t afford QS, as I’ll have to get logs elsewhere. The whole point of the renovation is to aquire and cut the wood in the same manner as the logs. The “Borgs” and even the local guys want so much for rough cut oak, it’s cheaper for me to go troll for logs and bring them back to my driveway…errr….logging deck. Thanks!

[Matt Kestenbaum]

Thomas,

Warping you should be able to prevent. Movement is a fact of life. To achieve the best shot at stability and resistance to warping you'll want to pay close attention to how the wood is handled from the minute the tree is felled. It'll make a difference. Are the logs' ends sealed? Once sawn they''' need to be properly stacked with stickers for some air drying. For the greatest resistance to future movement you'd probably want to then kiln dry the wood. Careful milling and good design should see you the rest of the way.

How are planning to the assemble the planks? Tongue and groove and nailed like flooring? Ship-lapped? You'll need a way to keep the planks flat (or at least encourage them to stay that way), but still allow them to expand and contract with the seasons -- in furniture all the age old joints are strategies to achieve this…breadboard ends, M&T, Buttons for holding table tops to aprons, etc.