Wasps are predatory insects that help control caterpillars and other insect populations. Though wasps are generally beneficial to the environment, they can be a problem if they construct a nest on your house, especially in an area of heavy activity. Most wasp nests you see on houses are those of the red wasp, also known as the paper wasp. The nest resembles an upside-down umbrella, with open cells in which the larvae grow. Before you ever attempt to remove a nest from your roof, make sure you kill the entire colony, or you could be stung multiple times.
Find the exact location of the nest. If you see heavy wasp activity around a particular area of your roof, there is probably a nest nearby. Look for the nest to be connected to the roof overhang or near any eaves in front of your attic. The nest will almost always be underneath the overhang, which serves as protection from the weather.
Wait until dusk or nighttime to treat the wasp nest. All of the wasps will return to the nest at dusk, which means you can kill them all with one treatment. Wasps are also dormant at night, which decreases your likelihood of getting stung.
Wear protective clothing. Put on long trousers, longs sleeves, a hat, and safety glasses. You want to protect yourself from any wasps that might attack you, as well as from the falling insecticide spray.
Stand slightly off to the side of the nest, not directly beneath it. Wasps will begin tumbling out of the nest after you begin soaking it, and the insecticide spray will also drip back down.
Spray the nest with the entire can of wasp insecticide spray, and completely douse the nest. Be very careful if you need to use a ladder to get close to the nest. Most wasp spray will shoot anywhere from 15 to 20 feet, so you may not need a ladder at all. Have an escape plan in place in case live wasps emerge from the nest.
Go into the house immediately after your can of wasp spray is empty. Wait until morning before returning to the nest site.
Knock the wasp nest free from the roof with a broom, an extension pole or a long tree branch. The nest should simply pop free once some pressure is put on it.
Put on gloves before handling the nest if it is still wet with insecticide spray. Dispose of the nest.