Water damage is costly to both homeowners and insurance companies. It is estimated that the cost of household water damage in California, alone, exceeded $500 million for 2002. While the number of water-related claims varies year to year, the average amount paid for such claims increased steadily from $2,577 in 1988 to $3,646 in 2002.
The high cost of water damage spotlights the importance of thorough investigation of the causes and origins of water losses. Understanding how moisture enters buildings and causes damage can be a challenge, as well as the most interesting aspect of a building inspection.
Determining whether a water-related claim is covered by the policy or is a building defect requires attention to detail, as well as special equipment. Often, water sources may be hidden behind walls. It also is common to find two or more water intrusion sources in the same location. Determining the primary source of water entry and the comparative value of each loss, while dealing with anxious insureds, adds to the challenge.
Cutting access holes into walls or using penetrating moisture meters in occupied locations should be done with the permission of the occupants. Damage should be kept to the minimum and, if possible, the site should be sealed while work occurs. It also is important to bear in mind safety issues, especially in the presence of children or immune-compromised occupants.
The investigator begins with a detailed examination of the outside of the building, looking for problems in the building envelope and drainage. Inspecting the landscape, the inspector should look at the slope of the land around the house and signs of high water tables related to neighboring wetlands.
The house's basement or crawlspace bulkhead doors should be inspected for erosion below the door and caulking failures around the doors. Stairways leading below grade should have drains at the landing and be free of accumulated debris. Basement window wells should have adequate drainage and the window caulking and trim should have good seals. Concrete aprons around the building should be slanted away from the building and the seams should be caulked. If a building is brick or masonry, the pointing should be checked for gaps.
Buildings with expanded foam insulation system exteriors should be inspected with failed caulking seams in mind, and buildings with vinyl or aluminum siding that is not original construction should be inspected with some concern for what may be covered.
Crawlspaces should be ventilated and well drained. The subfloor should be insulated with a vapor barrier protecting the warm side of the floor sheathing. If the crawlspace is dirt, it should be pitched for drainage and, ideally, covered with a vapor barrier to direct ground moisture away from the house. If water is a problem below the house, a sump pump should be well maintained and the water drained away from the house.
In environments that are so wet that crawlspaces cannot be kept dry, resulting in unsuccessful remediation efforts, mechanical exhaust fans should be present to maintain negative air pressure below the house to minimize moist air entry into the occupied areas. The floor joists and subfloor should be inspected for signs of chronic exposure, including wood decay, heavy insect presence, and fungal growth. Masonry surfaces should be inspected for efflorescence (deposited salts), indicating water entry through the foundation.
The building exterior should have gutters and downspouts that drain away from the house. Depending on its age, it should be noted whether the building has gable, ridge, soffit vents, or none of the above for ventilating the attic. Inspection of the exterior walls for water stains, microbial growth, excess shrubbery in close proximity to the house, and the condition of trim and caulking around the windows and doors should be included.
The roof should be looked at for missing or bulging shingles, the presence of metal drip edges, and the condition of chimney and valley flashing. Moss, algae, or mold on the exterior of the building are indicators of damp conditions. Overgrown trees and shrubs near the house may be aesthetically pleasing, but could prevent sunlight from drying the exterior of the house effectively.
Upon entering the building, the investigator should inspect the flooring at the entrance. Careful observation may indicate whether tracked-in water is a problem, particularly if the surface is unprotected carpet. One of the most ignored moisture problems in buildings is the condensation moisture on slab-on-grade floors. The earth generally is 20 degrees Fahrenheit cooler than the air temperature.
During periods of elevated relative humidity, condensation can occur when the temperature of a surface is below the dew point. Carpeted surfaces installed on concrete slabs may hide this moisture. Some recent building code changes, such as the Massachusetts energy code, require sub-slab insulation in commercial and multi-residential buildings to minimize this condensation moisture.
The same condensation can occur on basement walls. If the house has a basement that is unfinished, the inspector should examine the foundation wall construction. Old stone foundations are likely to be porous and allow moisture to enter the basement. Concrete block and poured concrete foundations should be tighter, particularly if coated on the exterior, but water stains on the concrete and around foundation windows, along with efflorescence, are signs of water entry.
Examination of the floor joists, insulation, and subfloor sheathing is recommended. If the first floor is air conditioned and the basement is not, the cool surface of the subfloor may condense moisture. The water heater and other mechanical equipment located in the basement should be inspected for rust or water marks from previous water entry.
Between the Walls
A finished basement introduces some new problems. The investigator should inspect for water stains and test the base of the exterior walls with a moisture meter. If moisture entry is suspected in any areas, it may be necessary to cut holes into the drywall.
Several techniques can be used for investigating moisture sources within walls. A moisture meter is the least invasive but cannot always indicate the sources of the moisture. Mapping the moisture at the base of walls, around windows, and around doors can determine whether the seals are failing.
Moisture patterns on flooring can indicate whether the moisture is coming from a leaking pipe or from an outdoor water intrusion. A boroscope and a relatively small hole can allow the investigator to observe the inside wall directly on the exterior wall or at a 90-degree angle. This should allow observation of leaking pipes or efflorescence on a hidden wall in a wall cavity, assuming insulation is not a major interference. Fiber optic videotaping is used in heating, ventilating, and air-conditioning duct exploration and in uninsulated wall cavities to look for water damage.
A relatively new tool, infrared light analysis of wall temperatures, can be used to evaluate wall moisture, both in the interiors and exteriors of buildings. Because water holds heat differently than many building materials, this analysis can be useful when other methods are unsuccessful. Although it is sensitive and non-invasive, it is not widely used, however, because of its cost and limitations. Outside testing must occur when sunlight is not present, and the results can be affected by metals.
In occupied areas of the house, the search for water damage should include careful examination of water stains and looking below sinks, bathroom fixtures, and around tubs, both visually and with a moisture meter. Again, there are occasions when slowly leaking pipes hidden in walls or animal nests (sources of urine) will not be observed and only destructive sampling of a suspected location will locate the moisture source. If holes must be drilled into finished walls, blank electrical plates to cover the holes can minimize the impact of the destructive testing. If possible, test holes may be cut inside closets and behind base moldings.
Attic inspections involve determining whether water damage is the result of condensation moisture, ice damming, or roofing failure. Widespread water damage or ice crystals on the lower surface of the roof sheathing in cold seasons are indicative of condensation moisture. Discoloration from water staining along the eaves, coupled with poor or obstructed soffit attic ventilation, is indicative of ice damming, as are icicles from the gutters in the winter. Water stains and streaks concentrated around chimneys and roof valleys indicate flashing and seal failures.
One of the most powerful tools for the building investigator is to be a good listener. Although some occupants may offer biased opinions, most insureds can provide valuable historic information, which can be confirmed or denied by careful examination. Understanding how water affects exposed building materials after single events, as opposed to chronic exposure, is another key to interpreting causations of water losses. Wood decay, for example, only occurs after long-term exposure, while efflorescence on masonry or concrete is not likely from one-time leaks. Putting all the clues together makes for an objective evaluation, which should stand up to the scrutiny of all parties.
EFI Global is a full-service Engineering, Fire Investigation, Environmental, Health and Safety, and specialty consulting firm. Over the last four decades, they have grown from a boutique firm to become a recognized leader in engineering failure analysis, origin and cause investigations, and environmental consulting. This expertise coupled with the extensive coverage of our 27 national offices, more than 400 professionals, and global work abroad capability allows EFI Global to deliver timely responses that consistently meets their clients' expectations.
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