Pests in Your Home

To prevent entry of pests of all kinds seal all entry points. Use appropriate sealing agents. Caulking comes in a variety of formulas for various uses. Ask at your local hardware store if you have any doubt about which is best. New products are constantly being released. Your hardware store worker should know the best and latest product for any specific use.

Seal all cracks and holes in the foundation, siding and around window and door frames. Caulking of different kinds can be used for most cracks and holes. Hydraulic cement might be appropriate where there is water entry. Steel wool might be best for plugging holes where rodents have entered. Foam insulation may be used to fill larger cavities like woodpecker holes. Some foam insulation expands tremendously and can caused damage from over expansion. Other foam insulation expands little. Be sure to use the correct formula.

Check window and door screens for damaged. Repair tears or other damage. Cover attic and crawlspace vents with tight weave screen.

Clean dryer vents to make sure the air operated flap inside opens and closes freely and completely. These need to cleaned regularly to prevent lint build up from wedging the flap open. Dryer vents and vents from gas burning appliances must never be screened.

Some birds and rodents can be frightened by devices like windblown plastic owls, or sound activated attack spiders. Owls are available at local gardening stores. Attack spiders are also sold as inexpensive Halloween decorations.

Once all entry points are sealed in the foundation and exterior walls check the roof. Birds, bats, wasp and hornets like to nest in sheltered areas like in and under soffits. These nests are mainly hard to prevent and removal must be added to routine maintenance tasks.

Remove debris like tree leaves and branches that have accumulated on the roof. Debris provides ideal conditions for insect growth and for the predators who eat them.

Clean all debris from gutters. There is an inexpensive a robot available for this called a “Looj” that makes gutter cleaner safer and easier. Cleaning gutters is a dangerous job that injures many people annually.

Look for places where water enters the house or penetrates the roofing. Open chimneys can be attractive to birds, bats, squirrels and rats. Water and debris combine for a friendly environment to fungi like wood rot and mold as well as bacteria, bugs, rodents, birds and reptiles. Functional fire burning chimneys need spark arrestors. These are basically steel screens in a housing on top of the chimney to prevent embers from floating out and starting fires. They also serve the function of preventing rain and snow from entering the chimney. Water in the chimney dissolves creosote from the inner walls creating an acid strong enough to dissolve mortar. Smoke and combustion gases can leak through brickwork as mortar dissolves threatening occupants.

Chimneys need a functional rain cap. This is a thin layer of cement poured on the top of the chimney to form a dome that sheds water. If the rain cap is cracked the freeze/thaw process of water will soon create an entry point. The rain cap must be regularly maintained.

Sewer vent pipes cannot be covered. Sewer gas is deadly and explosive. Furnace and water heater vents should be covered with a metal hood that deflects water and directs wind to prevent toxic gases from being blown back into the house. Check these hoods for rusting through and integrity of mount.

Look at all the flashings. These are made of metal, shingles, rubber, plastic or other materials. Flashings are installed at places where different roof planes meet or where the roof meets walls or penetrations. Some flashings may not be readily visible. Concentrate on those you can easily see. If flashings are allowing any water to pass to building materials they have failed. Failed flashing, or defective design/installation, are the most common.

This is a picture of an attic where the dryer vent emptied into the attic. The white stuff is a pile of dryer lint, several feet high, that has accumulated over the years. Dryer lint is so highly flammable that boy scouts light fires with it using a spark from a flint to ignite it.

Vents from bathrooms, kitchens, laundries and dryers are not allowed to be vented through the roof vents. These need their own vents that exit outside the roof. The attic needs an adequate insulation barrier for energy efficiency and healthy, comfortable living conditions in the house.

The most common insulation installation is laying batts between and on the ceiling rafters. This creates a separation between living area and attic. The attic stays cold in the winter to prevent quick snow melt that can result in ice damming. It stays relatively cool in the summer decreasing damage to building materials from heat. If batt insulation is installed with the vapor barrier to the cold side condensation can result inside insulation and promote mold growth and decay of building materials. An alternative to insulating the attic floor is to spray insulation on the underside of the roof deck creating a space totally isolated from the outside. The attic stays the same temperature as the living space. This is more energy-efficient.

Check all vent pipes that you can see passing from ceiling to roof. Do they exit the attic or do they exhaust inside? Vents from gas and wood burning devices, and plumbing, can release dangerous and noxious gases that can penetrate living areas. Dryer vents and bathroom exhaust fans that exit in the attic add moisture that can contribute to mold, rot, insects and rodents. No pipes should end in the attic.

Uninsulated heat or AC ducts that pass through attic or crawlspace are susceptible to condensation. Water condensed on these ducts can drip into insulation leaving it soaked. The air in the attic is so hot in the summer and cold in the winter that so much heat/cool can be lost to the air that neither system performs correctly.

Bathrooms, laundries and kitchens need to be places well ventilated. Check the window frames and sills for water stains. Stains here, or on walls or ceilings, indicate a condensation problem. There may be dark spots, patches or stains from fungal growth. Make sure these rooms have exhaust fans that are working and unobstructed, or other adequate ventilation. Install a larger volume vent fan if needed. Look for wet spots under sinks and around tubs, showers and toilets. Determine if the water comes from leaking water supply, or drains, or if it comes from water escaping tub or shower. Take appropriate action to remedy.

Check caulking and grout at tubs, showers, sinks and toilets. Repair where needed. Take inventory of your house plants. If you have so many large, well watered tropical plants that your windows fog and the humidity is noticeably higher than your neighbors, it may be time to reevaluate your watering practices or downsize your plant community.

Poisoning crickets, ants, spiders, roaches and other common bugs found in bathrooms, laundries and kitchens is a short-term solution. These poisons are also toxic to people and our pests. Use only in extreme cases. Remove the moisture from your home and they will disappear. They can’t live without it. The same is true for mold, other fungi and bacteria. All organic threats to your health, in your home, require moisture to exit and to grow. Sustained moisture is required for them to thrive.

If you have a crawlspace, consider adding a moisture barrier, if it doesn’t already have one in good repair. The most common moisture barrier is on the floor with insulation between the floor joist. This requires vents, usually on two opposing walls. Sometimes exhaust fans, similar to radon pumps, are installed that pump air out when it becomes too humid in the crawlspace.

Water coming through a foundation wall must be stopped from the outside with drainage correction before wall can be sealed effectively. A more energy-efficient technique is becoming popular. The moisture barrier and insulation are extended to the top of the foundation walls. No insulation is used in the floor joist. The crawlspace becomes part of the heated envelope, keeping it warm and dry. No vents are used. In some cases an underground drainage system must be installed to collect and remove water that might otherwise flood a basement or crawlspace. A sump, with or without a pump, may be required. Water leaking through the foundation must be stopped on the outside. It cannot be plugged from the inside.

A home that is dry inside and out is a relatively healthy, pest free home. Conditions friendly to you and me are mainly unfriendly to the things we find dangerous and pesty. A pest free home also tends to be more energy-efficient and more comfortable to live in. Copyright 2008, 2011 - all rights reserved