7 Common Problems With Insulation

Insulation problems are often overlooked because almost no one thinks about them. Out of sight–out of mind. Many people fail to equate insulation problems with higher energy costs, lack of comfort, offensive odors, and health problems.

Common Problems With Insulation

Most types of insulation are designed to last many decades. Even as it deteriorates over time, it continues to provide some benefits–just fewer. Common problems become apparent over time. Some of the causes are:

  • Inadequate Insulation. Not adhering to building codes. Older houses when codes were lower or non-existent. Old insulation past its best-before date.
  • Improper Installation. Not following installation guidelines reduces the effectiveness of the product.
  • Moisture Infiltration. Holes in the building envelope. High humidity. Poor vapor barrier. Flooding.
  • Wrong Choice of Insulation. Some types of insulation work better in different locations.
  • Over-Insulating. Too much attic insulation can reduce attic ventilation. Compressing fiberglass batts reduces R-value.
  • Age. Older insulation can slump and clump creating gaps in walls or lost R-value. Or full of dirt, pests, or just old.


Insulation that has slumped, is too thin, or improperly installed creates cold spots on walls, ceilings, and floors. Large differences between interior and exterior temperatures can cause condensation inside the stud cavities and even on walls. The problem is much worse in houses with high humidity levels.

Condensation problems occur in attics where too much insulation or poor application techniques restrict attic ventilation–allowing moisture build-up.

Crawl spaces and basements are often uninsulated or poorly insulated. These spaces are usually wet or humid. Condensation accumulates on walls, pipes, framing, and insulation. Wet insulation like fiberglass loses R-value–making the problems worse.

Mold, Odors, and Allergic Reactions

Condensation leads to mold growth. Mold smells musty and thrives in warm, moist locations with an organic food source. Mold damages framing, drywall, insulation, and furnishings. Mold odors and spores are a health hazard for people with allergies and compromised respiratory systems.

Some types of insulation off-gas formaldehyde–which causes even more serious health problems. Spray foam insulation that is mixed incorrectly off-gasses for days. With a foul odor and potential health risks. Wet fiberglass gives off a sickly sweet type of odor.

Asbestos insulation can cause serious lung problems. Most houses built before 1980 contain asbestos in some form. Treat it with caution.


Warm air always flows to cooler areas. A room feels drafty when warm air flows towards wall cold spots, which can be caused by poor, wet, or missing insulation.

A relatively inexpensive thermal imaging camera shows cold spots on walls, ceilings, and floors without damaging the drywall, ceiling, or flooring. Finding the cold areas enables spot repair.

Lack of insulation and weatherstripping around windows and doors causes many drafts. Fixing drafty windows and doors is good insulation practice.

Ice Dams

Ice dams along roof edges are a sign of improper attic insulation. Too much insulation improperly installed can reduce ventilation which removes moisture from the attic. Too little insulation allows the attic air to heat up and melt snow on the roof deck. Snow melt runs to the edges and freezes–a sure sign of attic insulation problems.

Increased Energy Costs

Poorly installed insulation or lack of insulation costs money. If energy bills are higher than neighboring properties, a professional energy audit may be necessary to find the causes. Fixing the problem saves money and increases comfort.


Pests like mice, rats, termites, and ants build nests that hollow out insulation and create cold spots. Insulation filled with pest feces and urine stinks and encourages mold growth. Pest infestations ruin insulation, increase energy costs, create cold spots, and are costly to repair.

Increased Noise

A significant amount of outside noise entering the house and/or echoes inside is a sign that the insulation may be inadequate or missing entirely. Stand in the middle of the room and speak normally. Echoes or a hollow sound indicate a lack of proper insulation. A thermal imaging camera is also helpful to pinpoint problem areas.