How do rodents get in my crawlspace?

• Posted on May 10, 2019
• by mikew
• in Fix It & Use It
• No Comments.

Rodents are motivated to get into your crawlspace because it is their Promised Land – safe, warm and they live at the top of the food chain!

There are three common ways I have seen rodents enter crawlspaces. The first is through the foundation wall where the sewer line enters. Crawlspace clean-up companies will install expanding foam around these points to ensure no space for pests to enter.

A second common way is through damaged or missing vent screens. The cable guy loves to run coaxial wire through crawlspaces, out vents and up walls. The problem is when they leave gaping holes in the mesh. As I have shared with many of my clients – a rat can fit through a hole the size of your thumb, a mouse can squeeze through a hole the size of your pinky finger. It doesn’t take much!

The third most common way is through inadequate outdoor crawlspace access covers. Covers need to be securely in place and latched. A rock or board leaning against the cover is not sufficient. I recommend a redundant system where there is both a top cover and foundation insert cover. Be sure wood in contact with dirt is treated to prolong its life. Rotting wood is easy for rodents to tunnel through.

Those little critters leave a mess that makes future crawlspace maintenance unbearable and clean-up very expensive. While we have moved into their neighborhood building our homes where they live, that doesn’t mean we have to basement neighbors.