Moisture content effecting the building

by Jesse Branham
(:Lagrange Indiana)

I am looking to deconstruct a barn and move it and convert it into a house. It is in good condition but its seen a lot of rain and just open air and humidity.

Wont the timbers move and buckle once its sealed insulated and heated na dries out? How does one overcome this issue? I'm scared of ruining good drywall, flooring not to mention safety concerns.

Answer:

Well it really depends, if the wood has been just saturated then it very well could move around and cause problems.

However in my experience most reclaimed barn wood never gets a higher moisture content than 20%, no matter if it is in the weather or not. Of course if it has just rained it is going to be higher on the outside, but that really doesn't effect its stability because the water doesn't penetrate deeply enough to effect it. With one caveat though, if it has been in water constantly for several months then the water is likely to have penetrated to the core.

But, from what you are describing I really don't think that is the case. Most of the time timbers from an old barn are the most stable wood you could possibly hope to obtain. It has had an opportunity to season for many decades and any movement that is going to happen already has.

Yes, when you start to heat the building you will get some shrinkage, that is the case no matter what wood you use. Wood is wood and it will most definitely shrink when it dries out. Is it going to shrink enough to effect your drywall and flooring? Most likely not.

If you want to be 100% sure there is an easy and cheap test you can perform. Get a moisture meter for determining the moisture content of wood. Cut a good slice off one of your timbers where you can afford to loose some length, I would say take as many inches off as the width of the timber, if it is an 8x8 take 8 inches off the end. Now test the moisture reading in several places on the cut. If the center 6 inches is less than say 18% you should be fine, although ideally you want to be between 4% and 12%. Also you will be able to see just how deep the moisture goes.

If your beams are just too wet, you can dry them by stacking them up off the ground with 1x1 sticks between each layer. Do not tarp them! Instead cover them with sheet goods of some sort with 1x1 stickers holding the sheet goods off the surface of the beams. Ideally you want to store them in a shady and breezy place outside. Or, you can of course pay someone to have them kiln dried.

I hope this helps, good luck with your project!

Have a great day!

Aaron Esch
-BarnGeek