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The Efficiency (and caution) of Experience

Experience is more than “been there, done that”. 

A story for inspectors and their customers.

Reprinted in the ASHI Reporter, Oct. 2010

How to benefit from your experiences without making a fool of yourself.


The customer’s request was to diagnose and recommend remedies for a chronic wet basement condition. When I arrived, the customer was on a telephone call, but he waved me in and escorted me to a finished bedroom in the rear left corner of the basement. The carpet had been pulled away from the corner, revealing a water damaged carpet tack strip, and a damp area of floor along the left wall about 4 feet from the corner.

  Damp basement floor. Moisture investigation by Roger Hankey, ASHI Certified Home Inspector in Winter Park, CO

The finished ceiling above this area had slight water damage and a dehumidifier was operating in the area where the carpet had been pulled back.

   (C) 2016 Damp ceiling and wall. Moisture investigation by Roger Hankey, ASHI Certified Home Inspector in Winter Park, CO

I told the customer I would go back out to the car for some equipment, which I did, but before re-entering, I walked around the exterior to the left rear corner of the house. Surface drainage was good at that area and the roof was equipped with a rain gutter with an 5 foot downspout extension. I saw no exterior conditions with the potential to create a wet basement. I did notice a plumbing vent on the roof that was about 4 feet in from the rear corner. I noted these conditions by taking a couple photos, and returned to the interior with my infrared (IR) thermal camera.

   Exterior conditions. Moisture investigation by Roger Hankey, ASHI Certified Home Inspector in Winter Park, CO


Before descending to the basement, I went into the main floor left rear room, which happened to be the kitchen. The kitchen sink was in the rear corner and its drain entered the side wall about 4 feet from the corner. The owner was still on the phone, but I told him I thought he had a leak at the kitchen sink drain. I asked a young boy about age 10, who was watching TV in the next room, to help me. He agreed and I showed him that I’d filled one basin of the kitchen sink with water. I told him to pull the stopper when I had returned to the basement. On my signal, he released the water from the sink into the drain. Less than a minute later, in the room below the kitchen, I saw a small water flow in the damp area on the floor between the base board and the carpet tack strip.

Next, I turned on my IR camera and viewed a thermal image of the wall and ceiling. The camera showed a cool area on the ceiling, consistent with water soaking the ceiling in the vicinity of the sink drain. I also asked the customer if he had observed any OTHER areas of dampness in the basement, and he said no.

     Infrared Thermal image of leak from a sink drain. Moisture investigation by Roger Hankey, ASHI Certified Home Inspector in Winter Park, CO

The actions I’ve just described took only ten minutes. The primary reason I was able to diagnose and verify this leak so quickly was that I had encountered three similar conditions in the past 5 years, including one in my own house. One of these prior conditions I’d even written up for our Moisture Mysteries page. The same story was also reprinted in the September 2009 ASHI Reporter.

As I discussed my findings with the customers, they indicated they had others attempt to diagnose this issue, but without success.

The rapid diagnosis of this leak illustrates the benefits of hiring an experienced home inspector. Qualified home inspectors are generalists who encounter a wide range of conditions, and if careful, will not only bring their experience to bear on the diagnosis, but will be open minded enough to exclude the assumptions of others or their own biases, from the inspection, and focus on the conditions found. I reached my preliminary diagnosis in this case as soon as I saw that the kitchen sink drain was directly above the water damage, but the remainder of the inspection process was the due diligence of verifying the preliminary diagnosis by doing the drain leak test, getting a history from the customer, and doing the IR thermal imaging. Failure to conduct these verifications could have led to embarrassing and/or costly faulty conclusions, including failure to identify multiple causes for the leak.  The diagnosis was made without the benefit of the IR camera, but use of the IR camera made verification easy. Use of a moisture meter would have been another effective verification method.

Home inspectors can benefit from this example, by applying the principles of a careful logical progression from gathering evidence, forming a plausible theory, testing the theory, and attempting to rule out other causes. While ASHI® Standards do not require the inspector to determine the cause of any adverse condition; the standards do require recommending a course of action, or further investigation. In problem solving cases such as this, calling for further investigation would be an admission that you could not determine the source of the leak. While a referral to other intrusive investigators may occasionally be necessary and appropriate, a typical moisture investigation customer expects an identification of the most likely cause of water intrusion, and a recommended course of action. The recommendation in this case was to have a qualified plumber repair the kitchen sink drain, and a qualified drywall firm to repair the wall and ceiling once the drain piping is corrected. The customer was happy to finally have this chronic condition diagnosed, since they had put up with this occasional dampness and a disrupted bedroom for months. The customer even posted a favorable report of our service on Angie’s List®.

You may also enjoy similar stories on our Moisture Mysteries page.

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