Unfortunately, a door's weather seals, if it has any at all, can rip, compress, bend, or wear out over time, leaving chilly winter air free to enter (or expensive air-conditioned air to leave). Fortunately, attaching new weather seals is a straightforward exercise, far cheaper and faster than installing a new door. And when you consider that even a tiny 1/8-inch gap around a typical entryway door is the equivalent of drilling a 5 ½-inch-diameter hole through an outside wall, closing that gap is well worth the effort. Any well-sealed door requires two components: weatherstripping, which covers the sides and top of the door, and a sweep, which fills the space between the threshold and the door bottom. Hardware stores and home centers sell an array of metal, foam, felt, and plastic products for this purpose. Tom prefers a weather seal system that includes a tubular silicone weatherstripping that fits against the doorstop and a twin-fin silicone sweep that fits beneath the door. Silicon makes an ideal weatherstripping because it's durable, soft, and has no "compression memory"; it remains tight as the door swells and shrinks. Read on here.

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