Quantifiable, qualified and quality recommendations.

This first picture is of a hot water pipe behind a wall taken with an Infrared thermometer.


At lower left in the picture is my finger pointing at the line that shows in the pictures below. Any pipe in a wall with hot or cold water in it can show up like this if the pipe is close enough to the wall and the temperature difference is great enough.

Two of the several types of moisture meters that I have can also find this pipe. In this case it is a “false positive” due to the pipe being metallic type pipe. If it was a plastic pipe it would not be a false positive but will tell you there is water behind the wall surface.

What it won’t necessarily tell you is if the water is harmlessly contained within the pipe.

The first moisture meter (Tramex) is a “sounding type moisture meter.” In “sounding” mode, the meter sends a signal into the material and depending on how the signal bounces back to the meter a “moisture content” reading is determined. But the signal is not very smart—it will bounce off all kinds of things and result in “false positive” readings.

This next picture shows a “normal” moisture reading for drywall at 0% with the Tramex Meter.


This next picture shows a “positive” (albeit false) reading of about 12% with the meter placed over the location of the pipe.


This next picture, with a second type of meter (Protimeter) shows a “normal” moisture reading for drywall at about 8-9 percent.


As you can see, with this meter placed over the pipe, we once again get a false positive reading of about 14%.


So if the inspector is curious as to whether there is “actually” moisture behind the wall, the next level of evaluation (without going Holmesallistic) would be to use the “pins” on the Protimeter type of meter to see if there is actually a positive reading at the surface of the material itself.

As you can see in this next picture the pin-probe reading is the same as the surface reading obtained with the same meter away from the location of the pipe.


Of course without physical signs of water damage to the wall, even if the pin-probe reading indicated moisture, it “could” still be a false positive.

For example the surface might be contaminated or painted with conductive materials that would fool the meter. In the real world this happens when areas have been flooded with salt water or pets have marked their territory etc. Some wall papers and paneling materials are somewhat conductive.

When I use a pin-probe type moisture meter on drywall and do not get a positive reading, I am confident that I have a higher level of certainty as to there not being a moisture issue than I will ever have with Infrared or pin-less type moisture meters.

So there are many levels of evaluation that the inspector will use to not only find issues but to verify issues and sometimes it is wise to qualify our conclusions, but in the end, the inspector must use his or her brain—and not solely rely on the tools as their disposal.

By Charles Buell, Real Estate Inspections in Seattle

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Why does my brand new house have mold growing on the roof sheathing?

There is some staining/discoloration and/or mold or mold-like fungal growth present on the roof sheathing in the attic.

radiativelosses1This condition may be consistent with the effects of Night Sky Radiation.

Night Sky Radiation is when the roof sheathing temperature falls below the ambient dew point temperature as a result of net radiative heat loss to the much cooler night sky. (see link below)

This is common in the Pacific Northwest Maritime Climate in the spring, winter and fall, where moist outdoor air is introduced to the attic via normal ventilation of the roof structure and the moisture condenses on the cold roof sheathing. Repeated wetting of the roof sheathing can lead to staining/minor deterioration of the wood and even result in fungal growth in some areas when wood moisture content is high enough—especially on the north side of the roof. Non-heartwood types of roof sheathings (whether plywood or OSB commonly used in newer construction) can contribute to worsening of this condition.

It should be noted that even if you do not live in a Maritime Climate, there may be localized conditions that can duplicate this phenomenon—at least seasonally.

The condition is more common in well insulated and air-sealed homes but may be present and masked by worse conditions in poorly insulated/air-sealed homes. Night Sky Radiation and other contributing factors should be part of any evaluation of how to address the condition.

Adding more ventilation can contribute to a worsening of this condition.

radiativelosses2Reducing ventilation to newer recommendations of 60/40 (60% lower/40% upper) may improve the condition. Metal roofs and insulating under the roof covering can help reduce the night sky radiation and result in less condensation on the roof sheathing. These options should be considered with the home is re-roofed.

Since this condition is considered to be “outside” the living environment and little structural damage is likely, minimizing its continued growth is recommended. Attempts to use surface treatments to discourage fungal growth are still in the experimental stages, with some treatments only making matters worse.

If you are trying to have your Building Performance Professional sort out what is going on in your attic, make sure they are familiar with the principles of Night Sky Radiation.

Why Wood Frame Attics Get Wet & Moldy in the Pacific Northwest

If for some reason the above link will not work you can try: Night Sky Radiation.


By Charles Buell, Real Estate Inspections in Seattle

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Who benefits from short inspection contingency periods?

I know I may be stepping into quick-sand with this question, but I am serious. All too often I see buyers forced to use inspectors they do not want to use, or in other ways not be able to do their due diligence because of very short of contingency periods.

DSCN0002I am busy enough that if the inspection contingency period is less than ten days, the chance of booking me goes way down. Now I typically have a list of other inspectors to help the buyer out when this occurs but they too are typically busy as well. What the client ends of with is an inspector capable of doing 3 and 4 inspections a day with the resultant mediocre report if not a mediocre inspection itself.

I am jealous of other parts of the country where I hear 10 and 12 day contingency periods are the norm while here 5 and 7 days is much more common.

It seems to me that in a rush to get the deal done, the only persons that benefit from this arrangement are the seller and the seller’s agent.

I know for a fact that many buyers feel there is considerable pressure to keep the ball rolling along, non-stop—at a pace that does not allow for second thoughts.

This freneticism is typically not present in commercial inspections–with 30 day contingency periods being common. Why the difference in Residential real estate sales? While I do not advocate 30 day contingency periods, a guaranteed 15 days sure would take the pressure off all parties and allow for a buyer’s due diligence.

Some might argue that I only care about this because I don’t want to lose the inspections—but the irony is that I am booked most of the time anyway, but it would allow for more clients who really want to book me a “chance” of getting me and would allow me to even-out my scheduling with far less cancellations.

Because of these short contingency periods, it is not uncommon for buyers or agents, who really want to use me, to call and “pencil me in” for a time slot in an “anticipated contingency window” only to have the deal not come together and leave me with time to blog–or an unneeded day off.

The real kicker is that the clients that wanted to use me, but whom I had to tell I was potentially booked, were also not best served.

Again it is business models that favor quick inspections with mediocre reports that are favored in this scenario. Neither of which benefits the consumer.

Short inspection contingency periods also affect, well inspections, septic system inspections, sewer scoping and even appraisals—let alone further evaluations by the professional trades that may be necessary.

Again, who really benefits from short contingency periods?


By Charles Buell, Real Estate Inspections in Seattle

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