More Moisture Discoveries

Thermal imaging makes this so much easier. . .




Jeff is that water damaged and or altered drywall in the picture with your moisture meter? Is this area adjacent to a bathroom, kitchen, laundry area, etc…?

Yep. This is actually near the front entry. The irrigation system was causing interior damage. . .

Did you have any idea that it was happening before you found it?

In this case I did. The jamb was rotted and the door itself had visible exterior damage. . .

No moisture but the absence of structural material (cripple studs) gave the dry rot away.

No moisture was present during the inspection but the absence of structural material (cripple studs) gave the dry rot away.


It is not nice to go and open up walls to prove your point on Inspections.
This could cost you money. ha. ha.

Marcel :slight_smile: :wink:

Tip of the day.
I always doing an Inspection try and shine my flash light down the wall in the Basement .
Been a flood 24 inches from the floor there could be a slight bulge where they have replaced the dry wall .
You can feel it with your hand usually too.
The above picture shows where they cut the dry wall .
… Cookie

And you know this from personal experience?


I always thought you were an Electrician, how did you pick up those tricks?

Were you watching other trades while you were making up those panels? ha. ha.

Ahh, I know, it is all those years in the field and beyond, right? :wink:

Know exactly how. ha. ha.


No actually I had a flood and saw How they did the work .
Two weeks later I am doing an inspection and it jumped out at me .
I said to the purchaser that I think this place has had a flood as I walked into the basement .
Sure enough she checked with here agent and the home owner admitted yes three years ago a huge storm had gone through and ever one on the street was flooded .
Two agents and One client though this guy is good .
I never told them that I could feel it instantly.
Three times since the same thing, easy to see when you know what to look for.
Off course I was trained by the Best.
… Cookie

Needs repeating.

Look for “normal” images. Anything abnormal (regardless of what abnormal displays itself as) should be checked.

Good catch.

So much missing insulation in the upstairs walls and ceilings,
it made the AC supply grills drip with condensation as the
cold air met the heat radiating into the rooms.

Also see this thermal imaging video clip



I bet that t-stat dosen’t shut anything down for long (ever)!

Some of my clients require definitive proof! :twisted:

Hasn’t cost me a dime Y.E.T

Those Texas inspectors are CRAZY, Marcel! If they suspect something wrong behind the drywall, they just puch a hole in it with their fist, then grab ahold and start tearing it out with their bare hands! You should see what happens when one of 'em accidently punches a stud!

Well… not John, he’s got that nice camera now.


I’m missing the connections here:
How does missing insulation cause dripping on the grilles?
How does cold air meeting “heat radiating into the rooms” cause condensation?

Missing insulation will cause the AC to run longer…which will/should remove more moisture from the air at the evaporator…which should make for much drier air!

Heat is a physical entity by itself and does not contain moisture. The missing insulation and heat radiating into rooms from walls and ceilings will not add humidity to the air.

The air RH must have been very high for some reason…but the AC evaporator should be removing more moisture from the air due to longer running times! The AC may be oversized which will quickly cool the air but not dehumidify it adequately since the house air volumes do not pass over the cold coils enough times to cause enough moisture to condense and lower the RH. This results in cold clammy air.

The biggest snafu I’ve heard of oversizing was a $25 million house in a very humid area of the globe. When the consultant (whom I know) got to the place, they’d already bought and installed portable dehumidifiers in every room.


Your missing the connections because you’re not looking at the entire picture.
It sounds like you have a background in HVAC?
Just enough to get you in trouble.

What does insulation do? Well, it depends on its type. Installation of itself reduces conductivity. Often applied with a barrier, insulation will reduce vapor, moisture (liquid) and air infiltration.
If we are missing insulation, were likely missing any form of vapor retardant.
Water vapor travels from high concentrations to lower concentrations. Without an adequate vapor barrier moisture will travel through the ceiling materials increasing water vapor content of the air within the house.

For starters, heat does not radiate into the room through the ceiling. It’s form of heat transfer is conduction.
It may radiate into the room through a window. So, your implication that the radiation will not cause condensation is an accurate assumption. However, I don’t think this is what you meant.

Cold air lowers the temperature of the supply air grill. The supply air grill is a penetration through the ceiling. The lack of insulation, (thus lack of vapor and air infiltration retardant) results in increased air infiltration around the register which then reduces heat energy from the air entering and condenses water vapor on the supply register.

That is correct, if this is in fact the case. We must first show that the increase of water vapor (latent heat) and sensible heat (conduction) is not exceeding the HVAC units capacity in btu/hr. If we conducted a psychrometric evaluation and provided this information to you, maybe you could figure that out. However, this is only an assumption. We don’t know if the air-conditioner is in fact running longer and keeping up with the heat load, however thermostat is on a 80° wall, so it probably won’t shut off. It all depends what somebody set it at .

We must consider the geographical location where Mr. McKenna conducts his business. It is very hot and it is very humid.

Missing insulation does not radiate moisture or temperature. But it does conduct, and as we said heat radiation does not increase humidity.
However, moisture is passing through the wall/ceiling where the building envelope construction is inadequate. It is likely (more than likely) that the association of decreased insulation is equivalent to decrease vapor retardant materials.

It is removing more moisture. However, reducing the moisture level in grains per pound will increase the transmittance of water vapor through the building materials. What makes you think that the air-conditioner can keep up with this infiltration? We are missing too much information here to be making these assumptions. Through psychrometric evaluation we can determine the sensible heat factor, however none of these evaluations were performed. Without additional information (which is outside the scope of Home Inspection), I think that the association between moisture condensation and building envelope deficiencies is a fairly accurate assumption on the part of Mr. McKenna.

Both of today’s inspections had significant missing ceiling insulation. The first two, one year old house, homeowner observed that the master suite was REALLY cold this winter and uncomfortably warm in the summer. Attic was not accessible. No insulation installed. Last one, new construction, preclosing upstairs gameroom incompletely insulated.

I am seeing this way too regularly. At the pre closing one, the construction super showed up and agreed to fix this area. But he tried to explain how he did not have to fix the other areas, smaller random places, because the home had passed city and “rescheck” inspection. Nice huh? Wouldn’t want to go above and below the bare minimum or even all the way to it if possible, especially if you already got your city permit.

No ceiling insulation - master closet.jpg

No ceiling insulation - master closet.jpg

No ceiling insulation - master bedroom.jpg

Incomplete ceiling insulation - gameroom.jpg