We build in solid cedar. Rough-cut boards, routed by hand, painted, and set on 6x6 cedar posts. That hasn't changed since 1982.
Cedar has oils in it that resist rot and insects. That's in the wood, not something we brush on afterward. It's the same reason people around here use it for fence posts and siding. It holds paint, it routes clean, and it stands up to Iowa weather about as well as anything you can put in the ground.
How long it lasts
Longer than most people expect. We've got signs we built that are still standing after more than twenty-five years in the ground.
Cedar wants a fresh coat of sealer every few years, same as anything else made of wood that lives outside. It's about two hours of work. You roll it on over the whole sign, then wipe it back off the painted areas with a rag. Keep after it and a cedar sign will outlast just about anything else you'd put at an entrance.
The finish is what matters most
This is the part nobody asks about, and it's the part that decides how long the sign lasts.
There are two kinds of finish. One sits on top and forms a film, like a varnish or a deck paint. The other soaks in.
A film looks good the first couple of years. Then it cracks somewhere, usually along the top edge where the sun works hardest. Water gets in through that crack and can't get back out, because the film everywhere else is still holding. The wood stays wet underneath and rots from the middle out. By the time anything shows on the surface, the board is gone.
We use a penetrating sealer. It soaks into the wood instead of sitting on top of it. Water still gets in, but it dries back out. That's why it needs recoating every few years, and it's also why the sign lasts.
We'll tell you exactly what we put on it, so you can buy the same thing when it's time.
Screws, not glue
We screw the joints from behind and use galvanized nails on anything exposed. No glue anywhere in it.
Glue joints on outdoor wood come apart eventually. The wood moves with the seasons and the glue doesn't, and after enough freeze and thaw cycles something has to give. Screws and nails let the boards move a little and hold anyway.
About the plastic ones
Some shops build out of high-density urethane now. It's a rigid foam that routes and paints something like wood, and it won't rot.
It has its place. But no matter how good the mold is, it hasn't got any grain in it, and up close it doesn't look like wood, because it isn't. You can get close. You can't get all the way there.
If that's what you're after, there are people who do it well. We build wood.
What you end up with
A sign made one at a time, out of real wood, built to stand out front for decades. Not something pulled off a shelf. Something made for that spot and no other.