Moisture Damage... How is that Determined?
We check for moisture damage with a resistance gauge by comparing the firmness from one area relative to that of another. When extensive damage is anticipated, a small core sample can be pulled to help verify the condition of the sheathing. We assign one of three different levels of resistance to testing sites: Firm, Soft or NONE. Areas which test "Soft" or "NONE" will be documented and outlined in red within the report elevation photo(s). Soft or None test sites should be further evaluated with core samples or removal of the siding. If core sampling was performed durning the inspection it will be documented within the report.
Moisture %... How Much is Too Much?
It is possible that a properly working wall system may have occasions of dampness but such dampness should dry quickly. Prolonged exposure to high moisture content (over 20%) can lead to moisture damage of the wall structure.
Levels that are considered dry range between 6%-19% for wood based sheathing and 0.1-0.6 for gypsum based sheathing. Although considered dry, levels between 15%-19% may be an indication some moisture intrusion, though unlikely to cause any harm if the siding has been installed correctly.
Possible Past Damage / Intermittent Intrusion (Monitor)
Substrate, such as OSB or Plywood is tested using a Structural Resistance Meter, which measures the amount of force the substrate will hold (in most cases 48 LBS). A baseline is created from a solid area of sheathing and subsequent test sites are measured for the same resistance. Any area of substrate that is 5 LBS of force below the baseline is marked in Orange as a possible area of past or intermittent moisture issues. Multiple test sites are taken when damage is suspected to ensure against false positives.
Elevated Moisture (At Risk/ Repair)
Levels 19%-40% in wood and 1.6-50 in gypsum are considered high with a high likelihood of current and/or future damage. Test sites are outlined in Blue in the report elevation photo(s) when the substrate is firm, but high moisture readings are present.
NONE (Very Likely Damaged)
Areas that did not hit substrate are documented in the report as NONE. This typically is an indication of extensive damage, although opening or missing areas of the sheathing are also a possibility.
Test sites are outlined in Red in the report elevation photo(s) When the substrate is missing or chronically damaged (i.e. Crumbling/Loose/Rotted) .
Note: Moisture readings may not be readable if the substrate is missing.