I have done more than 1,500 home inspections, and I still learn something almost every week. A few things I was sure I understood about houses turned out to be only half right, like the idea that more attic insulation is always better. Here are the things I thought I knew, and the ones I definitely didn’t, from smoke detector rules to how long your furnace will really last.

Things I Thought I Knew

I have always thought I am pretty handy and have a pretty good sense of things, but I learned quickly that was not fully the case.

Smoke and Carbon Monoxide Detectors

I had always known that smoke and carbon monoxide detectors were important, but I didn’t fully understand the requirements or the different types available. I have written a whole article about the differences between units and a larger breakdown of state requirements, but here is a quick overview for you. In Minnesota we are required to have a smoke detector in every bedroom and on every level. We are also required to have a carbon monoxide detector within 10 feet of every bedroom (one carbon monoxide detector can cover multiple rooms as long as it meets the distance requirements). I also learned that these detectors have a 7 to 10 year life expectancy. There should be an expiration or manufacture date on the unit itself, and if you can’t find one, it doesn’t hurt to just replace them.

GFCI Outlets

When was the last time you really thought about the outlets in your home? I can bet that most of us don’t have these at the forefront of our minds. A GFCI outlet, or Ground Fault Circuit Interrupter outlet, is a specialized outlet that continually monitors the flow of electricity within the circuit for electrical imbalances. If the outlet detects an imbalance, the circuit is tripped to reduce the likelihood of harm or damage. I knew that these were important, but I didn’t know why or where they should be located. To put it simply, GFCI protection should be present whenever an outlet is within 6 feet of a water source. I tell our clients that we should see them in the kitchen, bathroom, laundry room, garage, and the exterior of the home. Newer standards for homes built after 2023 also include any room below grade.

Attic Insulation

I remember my grandpa telling me, when I was a kid, about the house he grew up in always being cold in the winter because it didn’t have a lot of insulation. In those younger years my solution was to just add more insulation and you’ll be good. More is always better, right? In the winter, if I get cold, I just put more clothes on and I’m warmer. That’s not always the case with an attic. It is possible to over-insulate a space. Think about it this way. If you decide to run a marathon in the middle of February, would you wear a full down parka and heavy winter boots? No, you are creating heat and don’t want to get overheated. Similarly, too much insulation in an attic can trap excess heat and lead to moisture problems in the attic space. Excessive insulation can also reduce the movement of air, so the attic can’t breathe.

Things I Didn’t Know, but Do Now

Life Expectancy of Appliances

When was the last time you really thought about your furnace, or water heater, or your dishwasher? When was the last time you thought about how much longer those things may last? I would bet most people would say that question has probably never crossed their mind, and that’s okay. But here’s the deal. Conceptually I knew that nothing lives forever, but I didn’t have a real sense of what that actually looked like. With modern energy ratings and the cost of production (and a whole host of other things), the life expectancy of our appliances has gone down drastically. A high efficiency furnace (90% efficient or higher) lasts an average of 15 to 20 years with regular maintenance. A mid efficiency furnace (80 to 89% efficient) lasts 18 to 25 years with regular maintenance. Water heaters last around 8 to 12 years with regular maintenance, depending on water type and treatment. The three major kitchen appliances (refrigerator, range, and dishwasher) average about 10 years of life.

Radon

I didn’t really know much about radon and the long-term effects of exposure until I became a home inspector. I remember seeing it on the periodic table in high school, but didn’t really know where it came from or what it does. Radon is a naturally occurring radioactive gas that is found in the ground. Here in Minnesota, 2 in 5 homes have an actionable level of radon (4.0 pCi/L or greater), and radon is the second leading cause of lung cancer in the United States. Every home has some level of radon present, and the only way to truly know yours is to have your home tested. The odd part is that just because a neighbor’s home has an elevated level of radon does not mean your home will too, and vice versa. Thankfully, if your home does have an actionable level of radon, mitigation is possible and effective. If your home hasn’t been tested and you would like to find out its radon level, reach out to us at MarigoldHomeInspections.com/services/ or give us a call at 763-567-2181.

Cleanliness

I wrote a blog about how cleaning is a part of regular home maintenance. This wasn’t something that was ever on my mind before becoming a home inspector. It amazes me how quickly utilities and appliances wear out when they are not cleaned on a regular basis. Take your refrigerator, for instance. The coils on the back of your fridge help keep the compressor cool, but they also attract dust like nobody’s business. If those coils are caked in dust and grime, they lose their ability to cool the compressor. If the compressor overheats, it can fail, and there goes your fridge. Simply cleaning those coils on a regular basis will help prolong the life of your refrigerator. A very common issue we see is dirty furnace filters. Your HVAC system is essentially a giant air pump. If the filter is full of debris, the fan has to work harder to move air throughout your home, causing premature wear and tear on that system. Simply replacing your air filter on a regular basis will help extend the life of your HVAC system. If you’re unsure how often you should be changing your filter, look at it this way. If you have a 1-inch filter, replace it every 1 to 2 months. If you have a 3 to 4-inch filter, replace it every 3 to 6 months. For those thicker filters that are replaced less often, having them sent to you automatically is super helpful, or you could use a routine home maintenance service to handle that for you. Check out Marigold Home Services for more information on that.

Final Thoughts

As an inspector, I need to be willing to learn every day. Though I have done over 1,500 inspections (at the time of writing this), I know that I don’t know everything there is to know about homes and their systems. Home science is constantly changing and new things are being understood every year. That is probably one of the main reasons I love this job so much. It’s never the same thing twice in a day or even in a week. If you are looking for an inspector, ask about their continuing education requirements. Ask them about something they have learned lately, and if their answer is nothing, or they don’t have any continuing education requirements, that may be a sign to keep looking. Here at Marigold Home Inspections, all of our inspectors have been certified through InterNACHI and are required to complete 24 hours of continuing education a year. We have the mentality of always growing and always learning in all aspects of our jobs and lives.