Non-hardening electrical putty, also known as duct seal compound or mastic, is the preferred material for sealing wire entries directly inside the box. This pliable, non-toxic compound is easily molded by hand to form a plug around the wire bundle where it passes through the back. This blog provides guidance on the best practices for air-sealing electrical boxes, outlining key tips and recommending reliable products suited for the job. With the right materials and techniques, you can effectively air-seal electrical boxes and minimize air leakage. This practice is a fundamental part of maintaining a structure's envelope. Let's start with the “other equipment”. Typically, the biggest hole an electrician will make in a home's envelope will be for the main electrical service. Seal an electrical enclosure by matching the IP/NEMA rating, using the right gasket, cable glands, sealant, and inspection steps to block dust, water, and corrosion. Why? Any penetration into the walls can allow air to flow in and out of the conditioned space.
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