Clues to a probable roof leak

roof leak

I found several clues that indicated a serious moisture intrusion problem at this Eastside King County home.

Clue # 1: My first concern was when I pushed the plug tester into the wall. The outlet and plate cover came back out with the tester. Was the outlet box not nailed to the stud, or had something happened to the structural integrity of the stud.

Clue # 2: The hardwood floor in this area had substantial gaps. The adjacent hose bid pipe had problems in the past as the drywall had been removed in the garage. I don’t think this is the problem as most of the damage appears to be 2′ away from the plumbing pipe.

Clue # 3: I took a moisture reading of the area by the outlet. The reading was 40%. A reading 5′ away on the same wall was 13%.

Clue # 4: An infrared image was taken of the wall. The area by the outlet was reading colder. Wet insulation will produce a different reading than dry insulation

Darker areas indicate potential moisture inside wall

Clue # 5: While inspecting the adjacent garage, I found moisture ants on top of the foundation wall adjacent to the wet area inside the house

Home Inspections King County

Moisture Ants

Clue # 6: The crawl space inspection revealed moisture ants and repairs made to the mudsill, rim joist, and a scabbed on joist beneath the wet area of the house. This problem was known to the Seller as an attempt to repair damage was done in the past

Home Inspection Eastside

Floor joist, rim joist, and mudsill repair

Clue # 7: The siding by this area was very soft; I could have pushed my hand through it if I tried.  The concrete foundation wall had discoloration and pitting from the constant moisture

Home Inspection Sammamish

Pitted Foundation wall

Clue # 8: The source; a very poor design which is conducive to failure. My best guess at this time is that the moisture problem is from a valley in the roof that dives into the corner approximately 2′ horizontally from the wet spot in the house.

Home Inspector Seattle

Probable location of moisture intrusion

As a part of my Home Inspection report, I recommended that the drywall be removed in this area until (1) full stud bay in each direction is dry without any evidence of moisture. The damaged areas should reveal and verify the location of moisture intrusion.  It is most likely this repair will involve replacement of structural components.