I would think that doing nothing is the only way to ensure they continue to
look the way they do now.

Next closes would be a colored stain. I'll bet somone even has a color
called "Weathered Grey". Anything else is going to alter the color.

I would suspect that if they are old and in good condition then doing
nothing may be OK. Make sure there is zero earth to wood contact and that
all ground slopes away. Water will kill them. Ensure the roof doesn't leak.
Those things will go a long way in preserving the structure.

"rich brenz" wrote in message
...
A friend has a farm with several old barns. He wants to preserve the barns
in their natural "weathered gray" state. The barns are in otherwise
excellent structural condition. Is there an applicable wood treatment that
could be used that would not require power-washing or prepping the wood
beforehand? Remember, he wants to keep the aged patina of the barns.

Rich