Mould And Infrared

I just inspected a home for mould. I was in the home for about 1/2 a second when the smell of mould almost knocked me over. I took air samples in the home and visually inspected the entire home but only found one small location of visible mould. It was in one of the bathroom vanities. I know that the basement rugs were removed (supposedly because of moisture intrusion). I’m not very familiar with infrared technology. Would an infrared camera pin-point where the mould growth was in the walls and floor or would destructive testing be the only option here?

I don’t know what types of mould there are yet, I should get the results back on Tuesday.

No TI cameras are used for temperture differentials. They do not see mold. Typically if you smell it, it’s there somewhere.

Now what will the types of mold tell you?

I cannot say what is needed, if active water intrusion is occurring they yes the camera can help.

If your performing mold inspections for a fee, I hope you know what your doing. Did you check the AC system, look inside the duct work? Use a moisture meter on the walls in the basement? Look at the bottom of furniture legs? Determine where the “odor” was most signficant. What were the humidity levels at the areas of the house? Was the basement ventilated? Flip furniture over and look at the underside? Open closets and look at the clothing and leather goods, especially the shoes way in the back? Did you find where the water intrusion was occuring? Did you find out if it was fixed? Did you try to verify it was fixed? Did you calibrate your mold machine? Did you clean it before your last test? Where did you take your samples from? What samples did you use? Did you test for viable or non-viable mold? If it comes back high, how will you explain it to your client? If it doesn’t come back high, how will you explain it?

These are just the basics…


I did all the things you mentioned but didn’t feel the need to detail every part of my Inspection. My thought was that there may be temperature differentials or higher moisture levels within the walls where active mould might be. Unfortunately, like I mentioned, some of the building materials (carpet) were removed which hindered my efforts to track down the source of mould contamination.

If you want further details, I can provide you with some. The chimney cap was missing at the roof, 2 toilets were leaking into the floor, there appeared to be past moisture intrusion into the basement and at least 1 sink drain was currently leaking (where the visible mould was at the vanity). It was just strange to me that the smell was SOOO strong without any major signs of mould (even the ducts were all perfectly clean - I even pulled them apart at the furnace to verify this). Destructive testing would reveal which of these sources would be the most significant but I wasn’t sure if a thermal scan would make this process easier. I’m not trained in thermal imagery yet. The house was very bad but couldn’t pin-point the exact source of the mould although I saw numerous sources of potential moisture intrusion.

As you said toilets were leaking into the floor,sink drain was leaking this all might have caused the mould.High moisture levels can be the result of water coming in from the outside through the floor, walls or roof, or from plumbing leaks. And moisture causes these moulds to grow.

Infrared will be useful in detecting conducive conditions i.e.,. high moisture levels, but will not locate mold itself. Of course the areas must be wet at the time for infrared to pick them up. You may need to manipulate conditions as there will need to be a temperature differential for infrared to see. Typically this is provided by the process of evaporation but can also be accomplished leveraging the thermal capacitance of moisture in a changing temperature environment, where evaporation is not occurring. If the area was wet, but has since dried out, IR will be of very limited value even if mold is present.

If you find moisture you have mould concerns.

If you find mould, you have moisture concerns.

If you find mould, what are you going to do about it if you don’t know the source, cause and location of the moisture?

Just wondering…

There were multiple sources of moisture intrusion into the home. The toilets, the sinks and water leaking into the walls due to a negative grade around the home. The whole home was a mould-fest. Now with basically the entire grade being negative, I wanted to be sure that there wasn’t any further damage than what I had already found. My concern was when the home gets redone that ALL of the areas had been properly repaired and ALL of the areas of contamination had been found. My original question was whether an IR scan would aide in the diagnosis of this situation. It is winter so the wall may or may not be currently wet. Maybe when spring hits would be the time to suggest an IR scan.

The answer to your original question is, yes it will.

It should not be the sole diagnostic test to be performed however. You must focus on moisture measurement that will identify its source, cause and location.

In the winter water becomes a solid and site drainage issues may not be evident. This doesn’t mean that you should put off your investigation for a particular season however.

This type of testing seldom is taken care of in one visit. Things that we don’t expect to happen happen in conditions we expect to be good turn out to be bad.

I was working for a forensic engineering company concerning water leakage into a public building. I performed an initial site assessment and took thermal imaging scans in the process just to see what was going on under those particular conditions.

I decided to wait until a significant weather event occurred.
I was monitoring some thunderstorms on the radar and watched two massive super cells collide directly over the building dumping 8 .76 inches of rain in 15 minutes!

My follow-up investigation the following morning revealed no significant change in water intrusion into the building in comparison to the initial assessment I conduct did on a clear cloudless day with no previous rainfall. waiting for the appropriate moment was a waste of time.

So my recommendation is to begin collecting data as soon as possible regardless of whether you feel the conditions are appropriate.