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Insulation Defects: More Common Than Home Inspectors Might Think

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Insulation can keep homeowners comfortable in winter and summer or it can send conditioned air out the window along with hard-earned money. If it’s good, insulation affects the quality of life in a positive way. If it’s bad, the homeowner may never be truly comfortable with the way the home feels or how much it costs to heat and cool it.

There’s more to insulation defects than no insulation or hazardous asbestos. Here are some of the defects that you might find on the job.

Too Little Insulation

This is one of the most common problems and the easiest to correct. If the home has a single layer of fiberglass between the floor joists, that might suffice in a mild climate. For areas with cold winters, it’s probably not enough.

The U.S. Department of Energy ranks the United States in zones with a different recommended R-value range for each one. You can check out the zone map at this link. Unless the home has been recently updated, chances are it will benefit from a little more. Loose insulation can go directly over fiberglass batts or more loose material. If the new layer is fiberglass, it shouldn’t have a vapor barrier attached.

Reversed Vapor Barrier

How many times have well-meaning homeowners installed insulation upside down? Probably too many to count. The most common type of insulation, which is the fiberglass batt or blanket, often comes with paper attached to one side. That’s not a covering; it’s the vapor barrier.

Vapor barriers always face toward the living area. On an attic floor, the paper should face down. If there’s insulation on the walls, which isn’t necessary for an unfinished attic, it should face in toward the room.

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Vermiculite on an attic floor may contain hazardous asbestos and should be removed and replaced by a professional.

Dirty, Compressed Material

Insulation is light and fluffy when it’s new. Over time, it may take on an abundance of dust, debris, and other unsavory things such as droppings and nests from uninvited critters. If the insulation is filthy, it should be replaced because it can’t work as effectively as it should.

Insulation works because of the fluff factor—the air spaces inside. Fiberglass that’s flattened and dirty has very little air left inside. The fluffier the fiberglass, the better it performs at blocking thermal transfer.

Fiberglass or Foam in Ventilation Spaces

Overenthusiastic installers and homeowners may push insulation into places where it should never go. One of those places is the home’s built-in ventilation passageways. Around the perimeter of an unfinished attic floor, gaps between the joists and the walls or roof decking, depending on how the home is built, let the home breathe. Those gaps are vital to the home’s health.

If fiberglass or loose insulation blocks the ventilation, removing the material will fix the problem. If someone has sprayed foam insulation into the gaps, the only way to remove it is to cut it out. Left in place, the home may develop a host of problems, such as condensation buildup and wood rot.

Insulation on the Ceiling in an Unfinished Attic

If the insulation on the floor is good, more on the attic ceiling must be great! Not so fast. If it’s a finished attic, it does need insulation on the ceiling. If it’s not, it doesn’t. Not only that, insulating the ceiling of an unfinished attic can create new problems, such as condensation, for the homeowner.

The rule of thumb is ceiling or floor, not both. If the homeowners want to finish the attic, they need ceiling and wall insulation with no insulation on the floor. If the attic won’t be finished, insulation should only go on the floor.

Gaps Along Floor Joists and Around Openings

Wherever there’s a gap, insulation can’t work. Whether the home has loose insulation, batts, or spray foam, all of the spaces between joists and around openings for plumbing, electrical, and vent devices should be filled. The big exception is the ventilation space around the perimeter of the attic floor.

Spray foam in a small can works perfectly for filling in small gaps. But the homeowner should use care not to cover, block, or crowd electrical devices in the name of sealing off a leak.

The stack effect in homes means warm air rises. The only thing that prevents it from leaving the house entirely is attic insulation. Where there’s a space, warm air will go through it like a chimney.

Insulation is one of the simplest systems in any home, but it can have a tremendous effect on comfort and utility bills. The more defects you spot in an attic, the more places the new owners have to improve their living situation economically.

As you can see, being educated about systems in the home such as insulation will help you to become a better home inspector. ICA School can train you to become a certified home inspector on your own time and at your own pace. If you’ve thought about a new career, enroll now and start today.

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