A way to ventilate an attic or a wall cavity
A vent plug is a metal or plastic cylinder, usually fitted with a screen and louvers: hardware stores sell them in several diameters. To increase attic ventilation, fit vent plugs into evenly spaced holes drilled in the soffits with a spade bit or a hole saw.
If moisture in a wall cavity causes exterior paint to peel, try lowering indoor humidity. If that doesn’t work, you may have to ventilate the cavity by fitting vent plugs into the siding wherever paint is peeling. Plugs in siding reduce insulation effectiveness by up to 50 percent; use them only as a last resort.
Install two plugs between each pair of studs (see Studs), one near the bottom of the wall cavity, the other near the top (or, where there’s a window, just below the sill). Drill holes in the siding, then push in the plugs, louvers down.