Do Door Sweeps Keep Pests Out? A Saturday Fix for Brevard Homes

Yes, a door sweep keeps pests out, but only when it seals. A sweep that is worn, torn or set too high leaves a gap, and ants, roaches and mice use it. In Brevard County, with cooler nights coming and rats scouting for a way in, the door sweep on your garage and back doors is one of the cheapest fixes you can make in an afternoon.

TL;DR

A door sweep is the strip on the bottom of a door that closes the gap to the floor.
If you can see daylight under a closed door, a bug or a mouse can get in.
Fix it with a new sweep, a threshold, or a fresh rubber seal on the garage door.
Do the weather stripping on the sides and top at the same time.
A sweep helps. It does not replace checking the rest of the house.

Do door sweeps really work?

They work when the gap is the problem. A closed door should touch something all the way across. Most doors do not, especially after a few Florida summers of heat, rain and sun.

The size of the gap matters. The CDC says a mouse can squeeze through a hole about a quarter inch wide, and a rat needs about half an inch. Ants and roaches need far less. A door that clears the floor by a finger width is a wide open entry for all of them.

A sweep does nothing about a gap in the wall, the soffit, or a pipe. It handles the door, and only the door. That is still a good place to start, because doors are where pests walk in on foot.

How to check your door sweeps

This takes five minutes. Do it at night or in a dim room.

The light test. Close the door, turn off the lights inside, and shine a flashlight along the bottom from the outside. Or have someone stand outside with the flashlight. Any light you can see is a gap.
The finger test. Slide a pencil under the door. A mouse fits through a pencil width. If the pencil slides through, so can one.
Look at the rubber. Cracked, flattened, brittle or missing pieces mean the sweep is done.
Check the corners. The ends of a sweep are where it fails first, and where the weather stripping on the side of the door meets the floor.

What to buy

Keep it simple. A hardware store sweep costs a few dollars.

Pick the right type. A rubber or vinyl sweep in an aluminum channel fits most front and back doors. Measure the door width and buy one slightly longer, then cut it to fit.
Think about chewing. Rats gnaw soft rubber. For a garage or back door a rodent would like, pick a metal or heavy duty option.
Match it to the floor. An uneven slab or a worn threshold may need a threshold plate as well as the sweep, so the strip meets something flat.
Replace the side and top seals. Door stripping wears out at the same rate as the sweep, and a gap at the hinge side is as good as one at the bottom.

What to do about the garage door

The garage is the largest door on most Brevard homes, and its rubber seal is easy to forget. A flat, cracked or curled seal at the bottom, or a chewed corner, is a common way in. Our post on keeping rats out of your garage covers the seal and the corners in more detail.

What we see in Brevard

On Melbourne and Palm Bay homes, the doors people use least tend to be the worst. A side door to the garage, a laundry room door, or a back door onto the lanai gets little attention and the sweep sits for years. Roof rats also scout in fall, and a house with a gap at the door is easy to get into. Our post on how small a hole a rat can get through shows how little room a rat really needs.

What to do now

Walk around and test every exterior door. Front, back, garage side door, lanai door, and the garage door itself.
Note which ones show light. Write them down.
Replace the worn sweeps and seals. Buy the sweep and the side stripping together.
Set the sweep so it just touches the floor. Too tight makes the door drag. Too loose leaves the gap.
Test again with the flashlight once the new sweep is on.

When to call somebody

If you fix the doors and still hear scratching at night, or you find droppings, chewed wire or a trail of ants, the door was not the only way in. Our general pest control page explains what we check, and our rodent control page covers attic and wall problems. A worn door sweep alone is a Saturday job you can do yourself.

Sources

Frequently Asked Questions

Do door sweeps keep pests out?

Yes, when they seal. A sweep that is worn, torn or set too high leaves a gap, and ants, roaches and mice use it.

How do I check my door sweeps?

Close the door, shine a flashlight along the bottom from outside in a dim room, and look for light. You can also slide a pencil under the door. If it passes, a mouse can too.

How big a gap can a mouse or rat get through?

The CDC says a mouse can squeeze through a hole about a quarter inch wide, and a rat needs about half an inch. Ants and roaches need far less.

Do door sweeps stop rats?

A sweep closes the door gap only. Rats gnaw soft rubber, so pick a metal or heavy duty option for a door a rodent would like, and still check the soffit, vents and pipes.

When should I call a pest company?

If you fix the doors and still hear scratching at night, or find droppings, chewed wire or a trail of ants, the door was not the only way in.