Reclaimed lumber is hands-down the best choice for your lumber needs. Reclaimed wood has become an increasingly popular choice for architectural finishes including cabinets, flooring, siding, fencing, and furniture.
I’ve used reclaimed lumber for framing (used Douglas fir framing lumber), kitchen countertops (deconstructed maple bowling lanes), trim (the old backing boards for lathe and plaster sanded smooth), raised garden beds (old cedar fencing), and much more.
Reusing lumber is the best choice for the environment, too. This is a step above Forest Stewardship Council (FSC) certified lumber. With reclaimed lumber we make use of a product already manufactured and, in many cases, keep that product from going to a landfill.
I’m sure your choice to use reclaimed barn wood is driven by both the environmental benefits and the beauty of the wood itself. Reclaimed older wood often has a rich character with patinas and imperfections that add to the aesthetic. There’s nothing like old, well cared for wood to warm up the feeling of a room.
But your question is about safety. Yes, old lumber is safe. And it is much safer than many other products used for cabinetry, like MDF board. Many new composite products have formaldehyde and other toxins in the glues that bind them. You don’t have to worry about that with old barn wood.
Occasionally, there are some concerns that you may come across when handling old lumber.
Old, painted lumber (before 1978) may have lead-based paint on it that should be carefully removed and properly disposed of (or painted over so it is sealed in). You can buy inexpensive test kits for lead at most local hardware stores and learn in a matter of minutes if the paint is likely to contain lead.
Old lumber that has been pressure treated may have been treated with toxic chemicals that wouldn’t even be allowed under present-day laws. So if you told me you were going to use railroad ties or coal tar creosote-treated utility poles (containing known carcinogens) for your green kitchen cabinets, I’d have concerns. But barn wood should be free of those toxins.
A good general rule is this: If the lumber you are repurposing came from wood that was treated for wet environments (marine lumber, or lumber meant to sit on or in the soil), then you probably don’t want to use it again indoors. But if the lumber was above-ground framing or siding and doesn’t contain lead-based paint, then I think it is perfect for your kitchen cabinets and other projects.
We can usually see when wood has been treated. Paint is easy to spot. And we’d all be wary of the blackish goo on railroad ties. If the lumber you are using looks like raw lumber without any readily visible finish, then I think you can proceed safely.
Most barn wood is simply that... old raw wood that has been beautifully weathered for many years. If it was stained or sealed many years ago, at least the wood has had a long time to offgas. If there is an old finish on the wood that you don’t want, you can strip and sand the wood before reusing it. I had to strip the high-gloss finish off the bowling lanes I reused as kitchen cabinets until I had a raw maple butcher block.
My reclaimed bowling lanes came from Resource Conservation Group. They also sell barn wood and lots of other reclaimed lumber. Craigslist and Ebay are two other good sources to use to shop for used lumber.