Remove old, cracked caulk using a 5-in-1 tool or a stiff putty knife. Vacuum out dust and dirt. Wipe the area with rubbing alcohol—you need a pristine surface.

Wet your finger (or a plastic spoon) with soapy water. Run it lightly over the bead to push the caulk into the crack and smooth the surface.

You’ve felt it. That mysterious shiver while sitting on the couch. The way the curtains puff inward on a windy day. The sudden spike on your heating bill that makes you double-check the thermostat.