Leak or Condensation? Telling Them Apart
Not every drip is a roof leak, and roofing work will not fix a moisture problem that starts inside the house. In a Burlington winter, warm humid air leaking into a cold attic freezes as frost on the underside of the deck and on nail tips, then melts during the first mild spell and drips onto the ceiling.
Bathroom fans that vent into the attic, or into a soffit where the moist air gets drawn straight back in, are a frequent cause. Uninsulated ducts running through the attic can also sweat enough to stain the ceiling below them.
Clues that point to condensation rather than a leak include drips spread across a wide area, frost on many nail tips at once, and dripping on a dry, sunny day after a cold snap. In those cases the fix is air sealing, proper fan venting and attic ventilation, and we will tell you that rather than selling a roof repair.