Bathroom Moisture & Pest Inspection Checklist

Check plumbing connections under the sink — run your hand along pipes or wrap a tissue around joints to test for leaks or condensation; moisture is a survival requirement for silverfish and booklice

Inspect whether the floor drain is properly sealed — when not in use, cover with a silicone seal cap or water-trap insert to block cockroaches and drain flies from entering through the sewer system

Test the bathroom exhaust fan — turn it on and feel whether it blows air forcefully; the exterior vent outlet must have insect-proof fine mesh installed (prevents mosquitoes and cockroaches from crawling in from outside)

Check shower glass sealant and tile grout for aging, mold, or deterioration — replace any moldy sealant; moldy grout is a food source and hiding place for silverfish and springtails

Inspect the toilet base seal — water stains, odors, or blackening around the base indicate a failed wax ring seal that needs replacement

Flush drain pipes monthly with boiling water, or pour a baking soda and white vinegar mixture down each drain — clears organic buildup inside pipes that drain flies breed and lay eggs in

Open the bathtub side access panel — shine a flashlight inside to check for standing water, dead cockroaches, or rodent droppings (a frequently missed inspection area)

Check the wall surface behind towel racks and behind the toilet — look for bubbling paint, mold spots, or discoloration, which may signal a leak inside the wall; a leak equals a pest welcome sign

Wipe all toiletry bottle openings and caps clean — sugar- or protein-containing body wash and shampoo residue attracts ants and cockroaches

Install a door sweep at the bottom of the bathroom door and keep the door closed — this maintains negative pressure to prevent pests from escaping into other rooms, and helps the bathroom dry faster