Eugene from Ft. Worth, Tx writes
There really are not any products that are labeled for use in a chimney or fireplace. We recommend burning a fire in your fireplace for about 30 minutes as the heat will drive any hibernating insects out. You will want to check the screen to see if there is any finer mesh you can use that will still be safe for air/smoke flow at the top of the chimney.
You can spray an insecticide like Cyzmic CS or Delta Dust Insecticide / Tempo Dust into crevices around the outside of the fireplace and chimney of the home to help reduce the numbers flying around and gaining access. Treating the exterior foundation of the home, around windows, doors, under the eaves along rooflines, overhangs but also to bushes, trees, shrubs, etc where wasps may land or hide will also help.
In the winter when its cold, wasps and hornets cannot move much at all so this would be the ideal time to have the nest manually removed since they would be unable to fly or move quickly. Spraying monthly to quarterly throughout the main wasp and warm weather seasons will help achieve this.
Answer last updated on: 11/09/2021
