There are over 4,000 varieties of wasps in the U.S. While some wasps are harmless and nonaggressive, many can inflict powerful stings when provoked. Wasps are attracted to water so they often nest close to a swimming pool or bird bath, which is why wooden decks are a likely choice for building. There are simple ways to repel wasps from nesting on wood decks.
Remove any existing nests by spraying them with a commercial wasp killer at night when the insects are dormant. After all living insects have been destroyed, use a long stick to knock the nest into a plastic garbage bag and dispose of it immediately.
Cover any protein sources, such as pet food dishes and trash cans, during the spring and summer. According to the Earth Easy website, wasps look for areas where protein is readily available. In the fall and winter they are more drawn to sweet foods like fruit that has fallen from trees.
Staple the underside of your wood deck with aluminum foil, or rub it with a bar of soap. The Earth Easy website states that the soap will last through an entire season.
Set up a wasp trap near the deck. Follow the directions that come with the trap to easily trap and kill wasps in the area.
Spray the area with a commercial wasp repellent, or purchase a fake nest to set up in the area. Wasps won't build a nest if they see a possible rival close by.