Rodent-Proofing a Phoenix Home: Tile Roofs, Block Walls and Palms

Phoenix houses aren't built like houses back east. Most sit on a concrete slab with stucco walls, a tile or flat roof and a block wall around the yard, and that changes where rodents get in. Maricopa County Vector Control says rodents can get through any opening bigger than a nickel, and it recommends stucco diamond mesh for screening holes and vents.

Grab a flashlight and walk the house from the top down. It takes maybe half an hour, and you'll probably find at least one gap you didn't know about.

Up on the roofline

Concrete and clay tile roofs are everywhere in the Valley, and the weak spot is usually the eave, where the bottom row of tile leaves an open gap above the fascia. Rats slip in there and walk right into the attic. Flat roofs on older homes have their own gaps around parapets, roof jacks and old swamp cooler stands. If you hear rats up there now, start with roof rat trapping before you seal anything. Sealing rats in makes things worse, not better.

• Open gaps under the first row of tile
• Roof vents and gable vents with torn or missing screen
• Old swamp cooler openings nobody uses anymore
• Spots where solar panels, satellite lines and pipes cross the roof

Stucco, pipes and the garage door

Stucco cracks over time, and every pipe, AC line set and cable through it can leave a gap. Look low where the stucco meets the slab, and around hose bibs and the water heater closet. Check the garage door bottom seal and the side seals. If you can see daylight around the door from inside, a mouse can get through. Already finding droppings in the garage? Mouse control pairs trapping with these same fixes.

Inside, check where pipes come through the wall under the kitchen and bathroom sinks, behind the washer and dryer, and around the water heater. Those gaps often lead straight into the wall. Then pop the attic hatch. Droppings on the insulation, flattened paths or a urine smell mean rodents have been up there, and you'll want attic cleanup once they're gone and the roof is sealed.

The yard, the age of the house, and monsoon

The yard decides how many rodents come testing your house. Block walls are highways, palms and oleander and citrus are food and cover, and pools, fountains and drip lines are water in a place where water is scarce. Older homes have more gaps, period. Historic homes in Willo and Encanto have original vents, wood trim and sometimes raised floors. Midcentury homes in Maryvale often have retired cooler openings and decades of add-ons, so go slow and check where each addition meets the original walls.

Summer heat pushes rodents to shade and water, so garages, laundry rooms and pool equipment get busy. A big monsoon storm can flood ground nests and push rodents somewhere drier, so check the garage after one. Near the desert in Ahwatukee, check the shed and AC pad for fresh pack rat nests too. Door sweeps and vent screens make a fine weekend project. Tile is harder, since walking on it can crack it and every patch has to be something rats can't chew. If you find active rats or a lot of gaps, rodent exclusion is the next call.

• Trim palm skirts and keep palms off the roof
• Keep trees and shrubs several feet from the house
• Clear woodpiles, pavers and junk away from the walls
• Fix leaky drip emitters, faucets and pool equipment
• Bring pet food, water bowls and bird seed in at night
• Keep trash and recycling bins closed

See also: Rodent Exclusion, Mouse Control, Roof Rat Control