How do termite infestations weaken homes over time?

It's worth being direct about this before anything else: eastern subterranean termites, the only termite species established in New Hampshire, genuinely eat structural wood, and an untreated colony genuinely gets worse the longer it goes unaddressed. This page is not arguing that termite fear is manufactured. Among the pests covered in this cluster, subterranean termites are one of the clearest cases where the underlying concern is earned, well documented, and worth acting on promptly.

What this page audits is something more specific: the timeline. The claim that shows up constantly in marketing copy isn't 'termites cause structural damage' — it's 'termites will destroy your home almost overnight if you don't act now.' That specific speed claim is the part the evidence does not support.

An average eastern subterranean termite colony contains roughly 60,000 workers and eats only about a fifth of an ounce of wood a day — enough to consume roughly a foot of a two-by-four over five to six months. In the first weeks after a colony establishes near a structure, there's no measurable loss at all. Over the following months, feeding begins inside wood near soil contact, invisibly, without any external sign.

The timeline where the threat becomes genuinely serious is measured in years. NC State Extension states plainly that 'serious structural damage takes between 3 to 8 years of ongoing feeding and infestation to occur.' That's the honest clock: not days, not weeks — years of continuous, mostly hidden feeding before a homeowner is looking at meaningful structural loss. The rare worst-case endpoint — sagging floors, compromised framing — sits at the far end of that range, typically after a decade or more of a colony going completely undetected and untreated.

The 3-to-8-year figure already assumes ongoing feeding, and New Hampshire's climate slows that clock further. Subterranean termite activity drops off sharply as soil temperatures fall toward Manchester's first hard frost, historically around October 19 to 29 (NOAA), and feeding stays minimal through the cold months before resuming as the ground warms in spring. That seasonal pause doesn't stop an infestation, but it does mean a New Hampshire colony has fewer active feeding months per year than the same colony would have in a warmer climate — one more reason 'overnight collapse' doesn't match how this actually unfolds here.

Alongside the speed claim, you'll frequently see a dollar figure attached to termite damage nationally, often framed as exceeding the combined cost of fires, floods, and storms. That widely-repeated multi-billion-dollar annual termite figure is a pest-industry association's own estimate, not the output of a measured government damage survey — a trade-press investigation into its origin found it to be an extrapolation from insecticide-sales data rather than a systematic count of actual repairs. The peer-reviewed number it's often confused with is a global total, and the largest single share of that global figure is attributed to a termite species that isn't established in New Hampshire at all. None of that changes the honest local picture: eastern subterranean termites are a genuine, slow-moving structural risk here — it just means the number attached to the headline isn't one to repeat.