Climate Change Hits Home Foundations
Shifting Soil Is Threat to a House’s Foundation
Data from the National Oceanic and Atmospheric Association indicates that since the 1990s there has been an accelerating trend nationwide toward more extended dry periods followed by downpours. Whether due to random climate patterns or global warming, the swings between hot and dry weather and severe rain or snow have profoundly affected soil underneath buildings.
Clay soils, like those beneath the houses of Mr. Derse and Ms. Wilson, shrink during droughts and swell during floods, causing structures to bob. And because sandier soil loses its adhesive properties in dry conditions, it pulls away from foundations. Heavy rains cause it to shift or just collapse beneath structures. With both kinds of soil, such sinking, called subsidence, usually happens gradually, said Randall Orndorff, a geologist with the United States Geologic Survey. But, he said, “swinging from very wet to extremely dry weather like we’ve been seeing lately in many parts of the country may be accelerating the effect.”
Experts estimate the cost to homeowners to stabilize or shore up foundations is around $4 billion annually, up from $3 billion 10 years ago, although more houses have also been built in that time period. Subsidence is not covered by most homeowners’ insurance policies in the United States, unlike in Britain, where the increasing number of homeowners’ claims due to foundation failure prompted the Charter Insurance Institute, an industry trade group, to issue a dire warning about the financial drain in its 2009 report, “Coping with Climate Change: Risks and Opportunities for Insurers.”
“The question we need to ask is, are we building to cope with the enhanced weather events related to climate change,” said Brenda Ekwurzel, a climate scientist with the Union of Concerned Scientists, a nonprofit group advocating science-based solutions to environmental and health issues. “It’s obvious that we need to look at changing building codes worldwide to deal with this.”
Source: The New York Times
Erratic inquiries of Stowe Boyd, who means well, despite everything.
