Building a 12ft wooden gate is a bit more involved than building a smaller one, but it's still a relatively simple project. Here are the steps you'll need to take:
1. Cut your lumber to size. You'll need two vertical posts and two horizontal rails. The posts should be 12 feet tall, and the rails should be long enough to span the distance between them (plus a few inches for overlap).
2. Assemble the frame of your gate by attaching the rails to the posts with screws or nails. Make sure the frame is square and level before moving on.
3. Cut your pickets to size and attach them to the frame of your gate. Start at the bottom and work your way up, making sure that each picket is evenly spaced from its neighbors. You can use screws or nails for this step as well.
4. Hang your gate by attaching it to either side of your fence or driveway with hinges. Make sure that the hinges are properly secured so that your gate doesn't sag or fall off when opened.