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Makeup Air from Rainscreen Cavity

strausjw | Posted in General Questions on

Wondering if anybody can think of some risks/downsides to pulling air from the rainscreen cavity so that the vent does not penetrate the siding. Specifically thinking of doing this for a woodstove outside airkit, but presumably the same idea could be applied to passive inlets or range makeup air. Typically use roughsawn 1X material for strapping, so depth of cavity is about 1″ — seems like it would provide an adequate volume of air to draw from.

Access to the vent seem like the big downside, but intakes should not need regular cleaning and inspection the same way an exhaust vent might.

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  1. Expert Member


    First check your building code. Ours here in BC precludes terminating air intakes in the attic, crawlspace, or concealed spaces (like rain-screen gaps).

    Practically, for fireplace air I'd be worried that back-drafting could send embers into the cavity.

    Is there some compelling reason you don't want vents on the exterior? They are pretty easy to flash effectively and every house has a few.

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