Building with Green Water Oak

Building with timbers that have not been dried creates some degree of risk. September 27, 2008

Question
Will water oak air dry fairly well if put up wet as ceiling beams? They will be under roof and walls. No climate control will be in place for about a year. No roof decking will be set either for about a year. Are they likely to warp? Or just split a little? What can I expect? The size will be 4x8 by 16 feet span. Will they sag? Structure will have white roof shingles and interior will have open windows for ventilation.

Forum Responses
(Sawing and Drying Forum)
From contributor S:
You might be okay with green lumber, but then again, you might have problems... Is it worth the risk? How many beams are you going to use and how much would it cost you to get dry beams, maybe reclaimed antique lumber if they are going to show. How much is it going to cost you if you have problems with the beams and have to replace them?

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From the original questioner:
I am using 14 beams that will be structural (hold ceiling, wood decking, and support light roof) and will be cosmetic, as they will be seen. Do you think the worst case is cosmetic problems, or could there be structural? I am using overkill in size for the job.

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From Professor Gene Wengert, forum technical advisor:
All beams do not have the same strength, so they really need to be graded. A wet beam, if subsequently dried, will have the same strength as a dry beam. A wet beam will dry and shrink, crack, split and warp. This may affect strength. If not dried fast enough, they can mold and mildew. They may also have insects that persist when the wood is dry which can affect strength. Overall, what you propose has good risks of substandard performance.

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From contributor D:
I built with green red oak 6 x 6 x 12' long beams, and would not recommend it. Thirty years later, they show noticeable sagging, the joints pulled apart where they shrank, and one post twisted at least 10 degrees. They all have splits, and I have had a hard time keeping the roof from leaking. I knew better, but I was in a hurry. On the bright side, it hasn't fallen down yet! I hate to admit a mistake like that, but if it will spare someone else the problems, I'll take another bite of humble pie.

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From contributor B:
If the water oak you refer to is the same as our water oak, also called pin oak, then I’d be concerned with it shelling as it dries. We tend to not use it for anything important. With a 16’ span, I’d say it would sag some just under its own weight. Putting them in with any crown up would help. If you could stick and cover them and let them dry for even a couple of weeks, shell and bow would start to develop in the worst ones.