Sealing Homes For Pest Prevention

Sealing Homes For Pest Prevention

Part six in our pest prevention series

Homes have holes. Lots and lots of them. To keep pests out, you need to seal these holes. Homes have vents, and while these should not be sealed, they should be made inaccessible to insects and rodents.

Sealing your home against pests

It is a necessary fact of life. You have to breathe. Stop doing it for more than a couple of minutes, and you are a goner! Your home has to breathe too, and In order to breathe, in order to allow entry for pipes and cables, in order to vent heat and harmful gases, there have to be openings in a home. This is a list of the primary openings in a home, that is the important ones that are there for a reason. There may be others, like places that have separated over years of settling, cracks, and openings that were made for repairs, or made inadvertently over the years. Check your home closely for these.


  • Attic Vents: For dissipating heat.
  • Soffit Vents: For dissipating heat.
  • Plumbing Vents: For dissipating fumes and allowing the air needed for proper function of drainage systems.
  • Range vents: For dissipating the heat and smoke from cooking.
  • Hot gas vents for ventilating the hot gases from gas hot water heaters.
  • Dryer vents for dissipating the hot air from clothes dryers.
  • Fan vents, for removing nuisance odors from bathrooms.
  • Weep holes are small vents for allowing the drainage and drying of condensate from natural heating and cooling in the walls of your home, to prevent mold.

Other possible pest openings

Power, communication, and transmission lines and pipes

  • Air Conditioning Condensate drains: Very often, these are small copper pipes through the walls of the home. These allow the removal of moisture from air conditioning units.
  • Plumbing pipe openings: Allowing plumbing into your home; In most cases today, this is done through the floor of the concrete slab, but sometimes in other areas for homes on blocks or pier and beam construction.
  • Electrical lines. To allow electricity transmission: These are most often at the upper portion of an outside wall.
  • Cable communications lines: For satellite or cable line entry: The location can vary.

A home with out some forms of ventilation would soon destroy itself. A home without electricity, plumbing and communication would not be much fun!

So, how do we accommodate all these holes in our homes, and still keep little critters out? Well, that is what this is about.

How to close the border to pests


Before central heat and air, there were devices in homes to allow for the adjustment of temperature through the use of ventilation. We still have them in most homes today where they often serve as nothing more than vestiges of the ancient past. These were known as windows. Often the doors were used for the same purpose in the summer.

How did they manage to open these ventilation devices without allowing bugs in? This was accomplished through window and door screens. Taking a lesson from the past, we might consider the use of screens over the vents. Most home builders now screen vents, but there is always a chance, and you should check yours. Sometimes some are omitted by accident. I have seen a number of cases where rodents gained entry through dryer vents, and then chewed through the vent hose to get to the cheese and crackers. Write yourself a note to periodically check these vent screens for clogging.

Protecting other potential openings for pests

Other entry routes into the home, pipes and cables, will need to be sealed using another ancient technology: Caulk. A tube of high quality caulk is one of the best tools in home pest prevention. Seal around those entries on the outside of your home. Even the very small cracks and holes. You might be surprised just how small an insect or a rodent can become when it is hungry, thirsty, hot dry, wet or cold. When you are done with the outside of your home, you are not done!

Sealing indoors for pest prevention

On the inside of your house, you should do the same thing. Give special attention to plumbing drains. Very often a box was used to to form around the bathroom piping for the plumbers to make all the connections. If this area is not filled before the walls are completed, there will be exposed soil on the inside of the wall. Most pre-treatments for termites will lower the chances of anything coming into the home through these openings, but occasionally some do. If you have easy access to these areas through a pipe chase, filling the area with mortar or some other hardening substance is a good option, if not, the first time that a repair is made to your plumbing requiring a plumber to open up the wall, you might be able to do it. Otherwise, make sure that the inside wall is sealed well.

Caulking and sealing indoors

  • Caulking around doors and windows, inside and out should be checked, and resealed if needed.
  • Door sweeps should be checked and replaced if they do not reach the floor, or do not go all the way to the edges of the door.
  • All weather-stripping around doors and windows should be checked.
  • All screen doors should be in good order with no holes. The same is true of window screens. Look for a good fit. Check the window surface to surface seals where they open, make sure the seal is tight enough that the bugs can’t crawl between.
pest points of entry

Pest entry route caulked
Caulked pest entry point

If you have followed the other guidelines in this pest prevention series, the numbers of pests trying to get into your home will be few. If you will now seal your home as described here, you will have prevented the overwhelming majority of the remaining pests from entering, and are well on your way to a pest free home. The next section is an overview with some added common sense tips for home pest prevention.

See part seven in our pest prevention series!

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