Thermal imaging is the closest thing to seeing through walls that a home inspector can get, at least on the consumer market. It’s not cheap, but it’s powerful, especially in winter.
The key to thermal imaging is temperature differences. If the temperature inside a home is close to that of the outdoors, the technology won’t find much to impress you. But in winter, with outdoor freezing temperatures and cozy temps indoors, heat loss shows up in brilliant color on a thermal imaging device screen.
Winter might very well be the best time to use this technology. Here’s why.
#1: Roofs Show Where Heat Loss Occurs
You already know that heat travels up. It’s not because it prefers higher altitudes, but because heat moves to where temperatures are colder. Thermodynamics tells us so. It’s the stack effect, which relies on air leaks and ordinary ventilation in the home.
Because heat in an average house rises, attics need copious amounts of insulation. Installed correctly, insulation helps restrict heat transfer from the lower living spaces to the attic above. When insulation is poor, heat goes up and out through the roof. It also escapes through attic vents and air gaps.
Thermal imaging can spot heat transfer through the roof easier in winter than in summer. Indoor temperatures are warmer, so the temperature difference is more pronounced.
#2: Basements Can Reveal Water Infiltration
Thermal imaging isn’t just for finding heat loss. It can also indicate the possibility of water infiltration. When water pools on a basement floor, that’s evidence enough on its own. But when the water dries, it’s not so easy.
Water reads cooler than surrounding material with thermal imaging equipment. If a basement floor or walls have markedly colder spots, they might still be damp from a plumbing leak or from water runoff.
The thermal imaging results might not be conclusive, but they let you know there’s more to investigate. Because thermal devices cover a wide area at once, they let you know where to use a moisture detector for more definitive results.
#3: Windows Give Away Broken Seals and More Heat Transfer
The older the window, the more likely it is to let heat pass through. Heat doesn’t just move up, it transfers to where the temperature is colder. If there’s no thermal barrier besides a single pane of glass, expensive warm air can easily slip through the glass and raise heating bills.
Thermal imaging confirms heat loss at old windows in winter because a tremendous amount of heat can transfer through. But with newer windows that should have high insulating properties, this technology can find weak spots that need attention. That’s better than waiting for the homeowner to feel a draft.
Multi-pane windows are only as good as their factory seals, which enclose insulating gas between panes. When a gas seal breaks, the window has no more power to prevent heat transfer than two or three pieces of glass. It’s usually not repairable, at least not without help from the manufacturer. Thermal imaging can also spot air gaps around any window, which caulk can usually fix.
#4: Walls May Tell Secrets About Mold
Because a thermal device can detect the cold spots that indicate water, it can also hint to mold. In winter, water doesn’t tend to dry as quickly as it can in warm weather. The longer water is present, the more likely mold is to grow and thrive.
Thermal imaging doesn’t detect mold, but it gives you clues. If you smell that familiar, musty odor and the device registers a cold spot, you know where to investigate with a moisture detector. If the detector finds water, chances are there’s mold.
You might find evidence of mold under the floor or behind the wall if you can access the space. If not, the customer might want a mold inspection.
#5: Ceilings Point Out Ice Dams
Dampness along the edge of a ceiling can give away another problem that’s exclusive to winter weather: ice dams. There are lots of gadgets on the market that claim to help. But to really correct the problem, you have to correct the underlying cause. That’s usually a combination of ventilation and insulation defects.
If poor insulation and ventilation allow heat to transfer up to the roof, the warm roof can melt the underside of snow accumulation. As the temperature freezes again, often at night, it can create an ice dam along the edge of the roof.
Ice dams prevent proper water runoff. The only place for water to go is under the shingles, into the roofing substrate and into the house. If you see dark spots along the edge of the ceiling, it’s probably evidence of an ice dam. Your thermal imaging device can find cold spots that suggest dampness, even if there’s no ice dam on the roof at the time of the inspection.
Thermal imaging equipment isn’t cheap, but the price points are improving. FLIR isn’t the only tool on the market. There are even thermal imaging cameras that work with your mobile device. They take the price from thousands down to hundreds. Add thermal imaging to your toolkit this winter and you could help home buyers learn a lot more about the house they’ve fallen in love with.
Every tool that makes your job easier and helps you get better results for the customer is worth it. If your current home inspection reporting software leaves something to be desired, maybe it’s time to try something better. Download our home inspection app for Android or get it for your iPhone today.