David Valley's Real Estate/Home Inspection Blog


Ice Dams and Infrared (Thermal) Imaging

I've booked an excessive amount of ice dam calls (for help) this winter season and Infrared (Thermal) Imaging has assisted me in locating the exact cause of every last one of these ice dams.



Ice dams in Massachusetts are becoming a nuisance and are causing expensive damage to many soffit areas, gutters and the most outer portion of living area walls. First let me explain how this massive ice mound forms on the edge of your roof.

It snows and your roof will continue to accumulate this snow.

The temperature (outside) drops to below freezing.

The temperature inside your attic is above freezing, thus raising the temperature of your roofing material to above freezing.

Because of the temperature differential and the warmer roof, the snow on top of the roof starts to slowly melt and the melted snow (now water) starts to cascade down the roof (underneath all the accumulated snow) in an attempt to drain off the roof or into your gutters.

As soon as the water reaches the outer edge of the roof (where the roof will not be as warm as the attic cavity) it gets exposed to the freezing air. The cascading water now freezes into an ice mound along the edges of your roof and the gutters (if applicable).

As more and more melted snow (water) continues to cascade down your roof, it continues to freeze behind and on top of the previously frozen run off, forming a much larger ice dam. Once this ice dam takes shape, it will literally trap any water that is attempting to drain down and off the roof. Now, all the melting water is dammed and has nowhere to drain to, so it builds up. This accumulating water is simply backing up and is forced right under your roofing material and into your attic or soffit cavity (and then gravity takes over), and this water infiltration simply drips down onto your living area walls, causing the nuisance staining and damage that you are observing throughout your walls.

Preventing this ice from forming on the edge of your roof in the first place is absolutely preventable. Many homeowners are continuously researching articles on “HOW TO PREVENT ICE DAMS” and they learn that proper insulation and ventilation is necessary to prevent these ice dams. That’s fine, but after most homeowners obtain their education on “HOW TO PREVENT ICE DAMS” they may attempt to correct their ice dam situation, but are still baffled and are unable to figure out exactly where any improvement is needed. That’s why they call me.

Your solution to alleviate your ice dam issues is the use of Infrared technology. My infrared inspection is a brilliant method of providing you with an instant snapshot of any active heat loss through the most outer portion of your walls and ceilings of your home. Deficient insulation is a poor insulator, which makes it a great conductor of your conditioned air, and this is what enables me to easily detect the inefficient insulation in these areas. Thermal imaging will visually show thermal mapping of any improperly insulated ceiling and wall cavities that are causing the ice damming at the outer roof edges of your home.

Take a look at the images below and see how easy Infrared detects un-insulated cavities where ice dams are imminent...

Infrared clearly detects cold air (blue color) infiltrating the living area


Infrared detects an entire ceiling cavity missing insulation


Thermal imaging detects cold spots from improperly installed soffit vents


Infrared detects insulation issues above this bathroom ceiling.

Comment balloon 8 commentsDavid Valley • February 12 2009 12:39PM


David, great information and very good explanation of everything. Looks like you put some time into this one.

Posted by Ian Niquette (Square One Home Inspection) almost 12 years ago

Thank you Ian,


I can't believe how many calls I've received (this winter) regarding ice damming on roof edges and water seeping into living area walls. Every one of my ice damming client's now knows where their issues lie and they are now having them corrected.

I'm simply trying to inform the public that this ice dam issue can be resolved with a simple Infrared scan in under an hour.

Posted by David Valley, Massachusetts Home Inspections (Massachusetts Home Inspections) almost 12 years ago

David, excellent blog and really good IR pictures. Glad to see your busy.

Posted by Jack Gilleland (Home Inspection and Investor Services, Clayton) almost 12 years ago

Nice blog with pictures!


Posted by Gregory Scheer (GCS Home Inspections and Thermal Inspections) almost 12 years ago

Thank you, Jack.


Yes, Ice dams have been widespread in this area (especially this year), due to a couple of slush storms that we've had. It would snow for a few hours and then the rain would follow the snow squalls. This rain worsened the small ice dams that were already forming on the roof edges. The rain had nowhere to go but "IN" the houses.

When these homeowners call me, they mention Infrared scan. I'm happy to see that the public is now becoming informed of Infrared Technology. The funny thing is, when I arrive at some of these homes, I show my clients where their problem lies without the Infrared camera. After I tell them why their getting ice dams, I'll go ahead and show them the images of their ceiling through my IR screen.

Posted by David Valley, Massachusetts Home Inspections (Massachusetts Home Inspections) almost 12 years ago

Thank you, Greg.

For those HI's who are performing IR imaging, the cold winter months are definitely keeping us busy.

I've had calls (in the past) from potential clients who ask me to perform IR imaging in their home in the summer months. I ask them if they have A/C and they tell me that they don't. I tell them that temperature differential (Delta T) is crucial in order to obtain images on the Thermal Imaging camera. Then they tell me that they'll call me in the colder months.

Most people don't know that IR imaging requires a Delta T. It's necassary to have A/C in the summer months and sufficient heat in the winter months. The Infrared camera can only sense the temperature difference that transfers to the most outer surface of a wall, ceiling or floor (and if the Delta T, or temperature difference, cannot conduct this difference to the outer most surface, then my infrared camera is unable sense anything within the surfaces of a building). So it’s very crucial to have a temperature difference of at least ten degrees Fahrenheit between inside and outside temperatures.

Most materials that are moist or located inside inaccessible surfaces will have an absolute temperature difference in a seasonal situation due to conditioning the living areas with heat in the winter and A/C in the summer. In New England’s ever-changing weather, the inside and outside temperatures will contain sufficient differential most of the time. If the A/C or heat is not conditioning the home, and the outside temperature is the same as the inside temperature, then the infrared camera can not perform its intended function. Temperature differential is absolutely necessary for me to better interpret the camera images and its indicators.

Posted by David Valley, Massachusetts Home Inspections (Massachusetts Home Inspections) almost 12 years ago

Great pictures David

Posted by Brian Kelly (Dwelling Doctors LLC) almost 12 years ago

Thank you Brian.

Every one of thee pictures (and I've got more) are the results of ice damming in Massachusetts.

Posted by David Valley, Massachusetts Home Inspections (Massachusetts Home Inspections) almost 12 years ago

This blog does not allow anonymous comments