vapor barrier

American  

noun

Building Trades.

1. a layer of material, as plastic film or foil, used to protect installed insulation by retarding the transmission of moisture from the interior environment.

---

Etymology

Origin of vapor barrier

First recorded in 1940–45

Example Sentences

The current price to install traditional fiberglass batts and a plastic vapor barrier is $3,917.

From Seattle Times • Feb. 6, 2023

Nicholson & Galloway, an exterior restoration contractor experienced with historical domes, repaired cracks in tiles, patched concrete, then layered on new protective materials: a hand-troweled vapor barrier, spray foam insulation, stainless-steel framing, plywood sheathing.

From New York Times • Dec. 22, 2022

Another possibility, he says, is that the soil also provides a vapor barrier to help stifle sublimation as well as physical insulation.

From Science Magazine • Aug. 16, 2017

He had questions about a vapor barrier because the contractor he was thinking of hiring suggested one.

From Washington Post

The experimental uniforms, of which 150 have been tested, work on the "vapor barrier principle."

From Time Magazine Archive