By home inspectors for home inspectors

“Are you nuts?? It’s 42° out there, for cripes sake!”, the lovely wife stammered one chilly February morning last year, as she spied the door I had opened leading from the house to our enclosed porch. “Yes, it is!" I replied sensing yet another “teaching moment”,  "But don’t you remember what I told you about the 2^nd Law of Thermodynamics?” Her visible eye roll gave way to an “ugh, not this again” look…the look I’ve been accustomed to seeing whenever I’m getting ready to once again enlighten her with “boring science stuff.”

Much to her disheartenment, I pressed forward with my refresher on how the 2^nd Law of Thermodynamics tells us that heat moves towards cold. Always! So as soon as I opened the door, that 70° temperature in the house began to migrate towards the 42° porch. “Before long", I patiently explained, "it will balance out, and we will have transferred 60 square feet of sweeeeet living space into the plus column of our humble abode!”

“It’s the law!”, I asserted, as she scurried away into the bedroom. Undaunted, I sauntered after. “The law!” I repeated, thumbs hitched into my pockets, as she quietly closed the door behind her leaving me staring at 6-panels. 

That’s one of the fascinating things I learned back in the early days of my own Building Science education. Warm moves toward cold. If there is a difference in temperature, heat will move. Even 1° difference! And the greater the difference, the faster the heat will move! 

You know what else? That same law tells us that it works with pressure too! If there is a difference in pressure between two areas, high pressure will always move to low pressure. Nature abhors a vacuum and it also insists on things being balanced. This is why all the air molecules in a room don’t hang out in one corner, which would leave those of us on the other side of the room gasping for breath! Thanks, nature!! You're the best!!

This is also why it’s so important that a well-sealed fire separation is present between a house and an attached garage. As a rule, the interior of the house is under a “negative pressure” in relation to the garage. The house is the low-pressure side of the equation. The garage, on the other hand, is under “positive pressure”. This is the high-pressure side. Whatever is lurking in the garage wants to enter the house and it will, through tiny seemingly insignificant gaps and openings, through poorly sealed doors, through leaky duct-work. 

And what else is in the garage? Carbon monoxide, as soon as you start the car, back out and close the overhead as you head off to work! By the time you return, that carbon monoxide will be inside hanging out with your family. VOCs (volatile organic compounds) are also a problem, which can be emitted from a lawnmower, snow blower, solvents, stored gas and other chemicals that most people keep in their garages. 

Adding to that, did you know that wet always moves towards dry? It sure does! Think about a wet towel hanging on a towel bar. A couple hours later, the towel is dry. Where did that moisture go? It evaporated as it moved towards the dryer air, raising the humidity. This phenomenon is ongoing inside your house all the time. That is why it’s so important for buildings to be designed to control humidity and shed moisture away. Down and out! Rain will fall; snow will fall. And things need to be designed to shed and direct this moisture away. Otherwise, it will find a way to sneak in, resulting in high humidity, moisture damage to materials, and nasty things like mold growth! This is also why dehumidification is so important in basements and crawl spaces, especially during the summer months. And we as home inspectors need to stress this to our clients. Nobody else is doing it, save for the few building scientists out there shouting from the rooftops!!

Sadly, I learned none of this during my training to become a home inspector. And I’m supposed to be the “Expert Generalist” when I step into a house? Of course, that was over 27 years ago, so things had to have gotten better in that time-frame, right? Nope! Sadly, today there are exactly zero hours of training on building science in the NYS Home Inspector Qualifying Course curriculum. And virtually every indoor air quality issue to be had can be directly related to poor control of the indoor environment. (Asbestos has left the chat). Regardless of whether this is in our SOP, regardless of whether we are required to know this, if you are a working home inspector, an Expert Generalist, I encourage you to take a deep dive into the field of Building Science. You’ll become better equipped, far more knowledgeable, and a more capable inspector by adding this discipline to your toolbox! 

What’s that I hear? Why, it’s the bedroom door opening! I think the wife is coming back to continue our lesson!! Hey, what’s with the suitcase???