10 Surprising House Defects Uncovered By Home Inspectors

During my home inspection career, I have seen my fair share of house disasters. Whether it is environmental poisons (asbestos), roof damage, defective plumbing — you can be sure I have probably encountered it. Fortunately, my clients are allowed to walk away from the purchase if something comes up unexpected and if the Seller refuses to fix it. Here are just some of the house defects that I’ll never be able to forget about.

Basement Mold Growth

A couple years ago I did a mold inspection for a gentleman named Charlie. He told me that he went on vacation in the middle of August, and when he got home, the basement was covered in mold. I am talking about mold growing on every square inch of drywall including the ceiling. The entire basement needed to be demolished, sanitized, and refinished at a cost of $35,000.

mold growth

The interesting thing about this story is that the water heater sprung a small leak while he was on vacation. Charlie also made a fatal mistake by turning off the air conditioner. So when you combine the heat of August, no A/C system, and the small water heater leak — it created a mold disaster. Mold needs three things to grow: darkness, food (cellulose), and moisture.

Bad Deck Installations

You would be surprised how common it is for decks to be improperly installed. Whether it is missing flashing, rotted posts, or undersized bolts — all of these deck defects are big safety hazards. And when the deck issue is bad enough, it can literally cause the deck to collapse at the most unexpected times such as during large gatherings.

The most common reason for a deck collapse is when water get’s behind the deck’s ledger board where it’s bolted to the house framing. Missing or improper flashing is usually the culprit. If wood rot takes hold, it is only a matter of time for it to pull away and tumble like a house of cards.

Flexible Gas Lines (CSST)

If you have flexible gas lines in your home known as CSST (corrugated stainless steel tubing), then it is essential to make sure it is installed correctly. In the early 1990’s, it was discovered that this yellow-colored flexible piping was vulnerable to tiny holes when lightning would strike the home or even nearby.

The holes would release gas into the home and lead to fires and sometimes even explosions. The simple solution was to add a bonding cable (small copper wire) to prevent damage to the tubing.

Clogged Dryer Vents

The modern convenience of home dryers. We no longer need to drape our clothes over a line strung across two trees. And yet, with every new invention there are new maintenance requirements.

dryer vent fire

Many people don’t know that the dryer vent needs to be cleaned every 1-2 years. If your dryer duct gets clogged with lint or even a bird’s nest, it can lead to a deadly house fire. The National Fire Protection Association estimates that approximately 13,820 house fires were caused by dryer vents every year in the 2014-2018 period.

Sinking Foundations

If you have ever been in a home with a sinking foundation, you know the feeling. You enter the home and think there is something wrong here. A sinking foundation can cause windows to stick, floors to be uneven, hairline drywall cracks, and damage to the foundation. The most common reason for foundation movement is poor water drainage around the house.

sinking foundation

I can’t tell you how many times I have seen downspouts that send hundreds of gallons of water right next to the foundation. And if the soil is sloped towards the home, these water problems can cause the foundation to buckle, sink, and move. Fixing a foundation is a costly endeavor and can easily cost $25k to $50k or more.

Attic Mice Infestation

Mice, you either love ’em or you hate ’em — after all, some people keep them as pets. But most sane folk want to keep the little rascals out of their attic space. Unless you like the sound of mice scurrying above your head.

mice infestation

Mice leave perfectly round holes (around 1-2 inches) in the attic insulation. These holes are entrances to mice tunnels. Bad mice infestations require removing all attic insulation, exterminating the mice, sanitizing and sealing the attic space, and then re-installing new insulation. This eye-popping extermination job can easily cost over $20,000.

Polybutylene Piping

You may never of heard of polybutylene piping, and it sure is a mouthful. Some people call it PB for short, and it is definitely something to be familiar with. This plastic piping usually has a bluish-gray color and it has been known since the 1990’s to be prone to cracking.

During home inspections, I would see water stains all over the ceilings, and then discover the home has PB pipes. Sometimes even the main water line is made out of PB. Scientists discovered that PB is vulnerable to chlorine in the water which results in microfractures. The cost to replace an entire home’s polybutylene can cost anywhere from $10,000 to $30,000 depending on the size of home.

Aluminum Wiring

Beware of homes with aluminum wiring. You may love your aluminum foil, but you don’t want this metal keeping you awake at night. In the 1960’s, aluminum was used for branch wiring (outlets and lights) when copper prices became sky-high.

Source: Dadsconstruction.com

The problem with aluminum for regular outlets and lights is that it degrades much faster than copper and tends to overheat. If your home was built prior to the early 1970’s, you may have aluminum wiring.

Banned A/C Refrigerant

The government strikes again, this time for our cherished fluids. Starting in 2020, the USA has banned the production and importation of R-22 refrigerant for air conditioning systems. It is estimated that millions of homes still have A/C systems with this old refrigerant.

Imagine it’s a sweltering 110°F day, and the A/C goes out. You call over an HVAC contractor, and he tells you the A/C is leaking R-22 refrigerant. The bill turns out to be astronomical. It may be cheaper to just buy a new A/C system than filling it up with R-22.

Over-Powered Exhaust Fans

I think most people are aware of the potential hazards associated with carbon monoxide. I’ll skip the most common things such as leaving your car running in the garage or foolishly using a generator inside the home. However, most people don’t know that if a home has a too powerful exhaust fan, it can literally suck exhaust gases back into the home.

attic fan

An over-powered attic fan, whole house fan, or even a range hood can suck the combustion gases from a gas-fired water heater, furnace, or boiler back into the house. In fact, many local cities have building code that requires makeup air systems for powerful range hoods. These makeup air systems bring in fresh exterior air in order to avoid negative air pressure inside the home.

Meet Your Home Inspector Secrets Author

Ask Me A Question! Or Leave A Comment...

join the 'save my home' newsletter

Get a weekly email every Tuesday with a single home maintenance tip to save, protect, and improve your house!