Neighbors in Multi-Unit Housing can Pollute Your Home in Several Ways
Carl Brahe
People who live in multiple family buildings have always been affected by their neighbor’s living habits. Most apartment dwellers have been disturbed by noise, or cigarette smoke, from a neighboring unit. It can be annoying. It can also be a health hazard. If a wall, ceiling, or floor lets noise through it will probably allow other undesirable things to pass through. Tobacco smoke is probably the most common substance to invade homes from adjoining units. Other things can enter your home from adjoining units like:
- cockroaches, bedbugs and other insects
- mice and rats
- mold causing moisture
- smoke – from burning food and tobacco or other drugs
- fumes from cooking food or chemicals used in making drugs
Mold will grow almost anywhere sufficient moisture is maintained for more than a few hours. Mold can grow when there are plumbing leaks, or chronic water spillage. Mold growth can also result from excess humidity. This can be naturally occurring, be caused by excess plant watering, or from too many indoor plants. It can also be caused by a defective dryer or bathroom vent, or ventilation that does not exhaust to the outdoors. If this moisture has access to the inside party of party walls, common crawl spaces or attics, mold can grow. Water can drip, or run, into and behind walls, floors or ceilings, from leaks or condensation, creating prime conditions for mold growth. If access through the wall allows the moisture into your living space, mold may grow inside your unit as well. Mold spores from established colonies can spread with air flow through party walls. If your party walls are sealed there is no access for the moisture, or resulting mold growth, to enter your home from this source.
Crawl spaces and attics are sometimes shared by multiple units. Crawl spaces often have only one access hatch, but run under multiple units. Mold can grow if sufficient moisture is present and can enter living areas where access exists. Fumes from defective gas burning appliances and sewer gases from defective plumbing can accumulate in crawlspaces passing into living units above. The natural air flow in a building is from the lowest level to the highest as warmer air in the upper levels draws colder air upward. This action can also draw radon from the soil into living areas. Crawl spaces should have a functional moisture barrier along with an appropriate ventilation and/or insulation. All penetrations for things like plumbing, heating and electrical components should be sealed. Flooring should be properly installed to prevent airflow from below. An unhealthy environment in the crawlspace can affect your health even if you don’t have an access hatch in your unit.
In some multiple living buildings attics are shared by more than one unit. Fumes and mold can enter from other units, but more important so can people and fire. Modern building codes require firebreaks between the attic spaces above individual units. Some conversions, especially in older buildings, do not have this separation. If you live in one of these places your attic hatch should be latched from inside so it can’t be opened from above and sealed to prevent air flow. The same is true for bugs and rodents as for fumes. Mice can squeeze through holes as small as a dime. Holes the size of a quarter allows rats access. These things can’t enter your home if there is no access. Cockroaches feed on almost anything from human dander, to crumbs of human food, building materials and furniture. If the food and moisture are available these bugs will thrive.
Keeping your home clean and dry keeps cockroaches, and most other pest away, but what if your neighbors are not so clean? If the bugs have access to your home they will come. These days, it is as likely that you will have bedbugs invade your home as cockroaches. Both bugs hide in crevices, crannies and voids in the daytime and come out to feed at night. Cockroaches spread disease and require a certain amount of filth to survive. Cockroaches eat almost anything. Bedbugs eat only blood and are not known to carry disease. Both can find their way into your home through common walls from neighbors homes.
Meth use, or manufacture, by a neighbor with a common wall/floor/ceiling can contaminate your home with the actual drug, or with chemicals involved in making it. Most meth manufacture is done in very small batches for the personal use of the maker. Regardless of the amount made it is possible to contaminate surrounding living units with a variety of chemicals including some carcinogens. Smoking meth also contaminates surroundings and can make occupants sick.
People living adjacent to meth users/manufacturers have reported health problems including meth intoxication and testing positive for meth in their bodies. Besides the health implications there can be legal issues as well. A person may test positive for meth without ever using it from contamination from neighboring living units. Children have been removed from homes after testing positive for meth over the objections of parents who claim there has never been meth use in their homes. Jobs can be jeopardized by testing positive for meth from environmental exposure. You can test for meth in your body, or children's bodies, using a saliva test that checks for the drug itself and its metabolites.
In general, the more soundproof a wall, floor or ceiling is, the more air tight it is and the less sound, fumes or creatures are able to penetrate it. There are a variety of ways to make a wall/ceiling/floor more airtight and soundproof. The easiest improvements is adding foam insulating pads to outlets, switches and light fixtures to stop airflow around them. Anything that penetrates a party wall/ceiling/floor can be a source for air flow. These places can be caulked or gasketed with foam tape, or precut foam gaskets from the hardware store. As a plus these measure all improve energy efficiency. Air movement can happen through any gap in the building materials of party walls/floors/ceilings.
One function of trim is to cover gaps. The most common gaps occur at the bottom of the wall hidden by the trim. Large gaps can exit here. When drywall is installed the slack is taken up by lifting the sheets upward with the possibility of leaving the bottom unsealed. These areas can be sealed with caulking. Pry off the trim to caulk behind. Where carpet is installed access to the gap may be limited by the tack board that holds the carpet in place at the edges. If necessary pry up the tack board to caulk behind. Use a non-shrinking caulking that will not pull out of voids when dried. If very large gaps exist expanding foam may be used. Be very careful using expanding foam. It can expand beyond expectations. If too much is forced into a void, such as a wall cavity, the wall can burst in your home or your neighbor’s. If you get expanding foam on your hands, cloths, carpet, drapes, furniture, pets or children you can’t clean it off. It sticks to everything.
After sealing gaps behind trim replace tack boards and roll carpet edges back into place. Replace the trim. Carefully place nails in original holes and hammer gently back into place. Use a piece of wood placed along the length of the trim to hammer back with minimal damage. Use a nail set to finish driving nails into place to avoid hammer marks on the trim. Nail heads can be covered by spackling or other material that matches the trim.
Modern building codes require that party walls/ceilings/floors restrain a fire for two hours. In most cases, this means two interior type walls/floors/ceilings with a gap between them. The back side of the wall/floor/ceiling may be enclosed with drywall or other appropriate material. The walls may or may not be insulated. In some cases this wall can be a single wall that restrains a fire for 2 hours. Building codes for older and converted buildings may have allowed no separation between units. Upgrades are usually required during remodel or renovation.
Insulation of various kinds can be pumped through holes drilled in walls/floors/ceilings to dampen sound and airflow. Two or more holes, up to several inches in diameter, are drilled between each set of framing studs. One hole is drilled to pump the insulation through. Other holes act as relief holes where the insulation escapes signaling that the void is filled. Various expanding foams, shredded blue jeans or paper, and other blown in insulation may be used. For most people living in multiple living units only basic sealing may be practical. More extensive sealing and insulating might be considered during remodeling, especially if a complete gutting is involved.
When considering moving into a multiple living unit building consider how pests, fumes and moisture may enter from neighboring units. Even in the most expensive apartments tobacco smokers, bed bugs, cockroaches, rodents, meth smokers and makers, and errant moisture from overzealous indoor gardening and chronic hidden plumbing leaks, happen. Most construction is done to minimum code. That means it is the poorest quality allowed. Expect minimum quality, but where construction is more soundproof building quality is probably higher with less than average air flow access between units. The more common air you share with your neighbors, the more possibility for pests, smoke, fumes and moisture to enter from neighboring units. The more airflow from your neighbors homes to yours the less control over the health of you home.