Your home’s crawlspace is often out of sight, out of mind—but it’s a prime target for rodents seeking shelter as the weather cools, especially in Portland where most homes have a crawlspace of some sort underneath them. Understanding how rodents can damage your crawlspace can help you take preventive measures before problems escalate.
Traditional crawlspaces are usually surrounded by a cement foundation, although some home styles like older victorian style homes will have a wooden skirt around the outside instead of a cement foundation. These types of homes are particularly vulnerable to rodent intrusion, but we will be focusing on traditional cement foundations for this blog post.
Crawlspaces offer rodents the protection they need from predators and harsh weather. They’re often dark, damp, and quiet, making them an ideal nesting site for rats and mice. Unfortunately, rodents can cause significant damage to your home’s structure and systems including damaging the electrical, plumbing, and insulation.
Common Types of Damage:
Insulation destruction: Rodents often chew through insulation to create nesting materials, leading to decreased energy efficiency and higher utility bills.
Chewed wires: Rats and mice have a natural instinct to gnaw, and electrical wires are a common target. This can create fire hazards or cause electrical malfunctions. If you see exposed wiring in your crawlspace or attic due to rodents or squirrels call a professional right away to assess the situation.
Contamination: Rodent droppings and urine can contaminate your crawlspace insulation and vapor barrier leading to unpleasant odors and potential health risks, particularly of respiratory illnesses. Proper remediation and cleanup is an essential part of a good rodent control program. Simply eliminating the rodents is a good first step, sealing up entry points is also vital, but oftentimes the vapor barrier or insulation will need to be replaced as well.
Signs of Rodent Activity in Your Crawlspace:
Droppings: Rodent droppings are a clear sign of infestation. Look for them along walls, in corners, or near insulation.
Gnaw marks: Check for gnaw marks on wood, insulation, or wires.
Nesting materials: Rodents may bring in materials like shredded paper, fabric, or insulation to build nests. If you see that the subfloor insulation in your crawlspace is damaged or torn down then that is a common sign of rodent or other wildlife related damage.
Preventive Steps:
Seal entry points: Inspect your crawlspace for gaps or cracks and seal them with durable materials to prevent rodents from entering. This is the number one piece of advice we can give Portland home owners – seal up the entry points. Check for rodent burrows around your foundation as well. 
Trapping/Baiting: Using traps or bait stations to monitor for rodent activity is the best way to prevent an infestation. The Portland area is currently being overrun by rats due to many factors and if your home doesn’t have traps or bait stations around the exterior it might be at risk of an infestation.
Install a vapor barrier: A vapor barrier can help keep moisture levels low, making the crawlspace less attractive to rodents.
Regular inspections: Schedule regular inspections of your crawlspace, especially in the fall, to catch any signs of rodent activity early. Also checking all of your vent screens every 6 months can be a great way to eliminate rodent entry points and catch issues before they become a full blown infestation.
Protect your crawlspace from rodent damage this fall. If you notice signs of rodents or want to take preventative action, call Pest Patrol at 503-985-6524. We specialize in keeping Portland homes safe from rodents and the damage they cause.
