Case Studies

Wildlife Removal Case Studies: Squirrels chew into Metuchen, NJ home through static vent.

Thursday, February 7th, 2019 by Tom Reilly


Squirrels were entering this home in Metuchen, NJ so I went to investigate. Here’s the background. Static vents (roof louvers) vents are essential part of any roof design. These low-rising vents are necessary to move hot air and moisture out of the attic to help ventilate the home. As far as a home’s internal temperature and the outside temperature that envelopes your home, your attic is like a war zone. There is an ongoing battle of hot and cold air and neither side ever claims victory. During the summer, we deal with cool conditioned air on the inside and humid sticky air outside, and in the winter, the positions are reversed. We have heated air inside and cold temperatures on the outside. This battle of hot and cold results in a build-up of static pressure. Dense cold air sinks while thinner hot air rises, and the build-up of air in an enclosed space can result in tremendous static pressure. For homes with attics without an effective ventilation system to release this pressure, it can build up to levels that can literally blow the roof off a home.

Static vents are stationary with no moving parts. Since they are flat, they can be hard to inspect without actually climbing on the roof. So, if there is a wildlife infestation through the roof, it’s time for me to take out the ladder and get a closer look. Unfortunately, most of the static vent that I’ve inspected are made of cheap plastic, and after years of exposure to the harsh outdoor elements, it becomes weak and brittle, and is exploited by squirrels and other wildlife. It doesn’t take much effort for these animals to rip these weather-damaged vents clean off. 


This home had two static vents. One of them had some “construction work” done by an industrious squirrel that had made a semi-circular entranceway into the home. Given the condition of these vents, I’d say it took just a few minutes for a squirrel to gain entry. 

I installed a custom vent cover with a “one way” on it over the vent that was accessed by the wildlife. These one-way devices allow animals to exit, but prevents their return. I also secured three baited traps on the roof. For the other vent, I installed a galvanized steel cover that would prevent squirrels or other nuisance wildlife from clawing their way inside. Once the trapping is completed, I’ll remove the one-way cover and replace it with a permanent one that will match the cover installed on the other vent. These covers look great and last for many years. Vent covers are often skipped during the initial home construction, which then cause issues for the homeowner years later with either a wildlife infestation or water leak. Often, just like here, this is how the homeowner finds out that there is a roof problem.