Roofing in New Hampshire depends on which roof the snow sits on. Mountain pitches carry a load that stays for months and then slides. Seacoast roofs take salt wind that lifts tabs and rusts flashing. Lakes houses often have low additions, skylights, and a porch roof tied in badly. Valley houses ice at the eave over a warm attic. Name the region and the material before you describe the stain.
Chimney flashing and the warm eave are the usual indoor paths. A missing cricket holds ice on the uphill side. Valleys full of pine needles dam the melt. Metal roofs are common in the north because snow sheds, and they send that snow onto decks, walks, and lower roofs. That slide is part of the design, not a surprise to omit. If you can see the attic, say whether the boards are wet or only the ceiling below stains during a thaw.
A second layer over a soft deck hides the rot until a boot goes through. Underlayment and ice protection at the eaves matter more where meltwater refreezes, which is most of the state away from the immediate shore. Slate in older villages fails at the nails and the hips. Shingle caps blow off on an exposed Seacoast ridge. Note antennas, mounts, and any boot that has already split.
Access after a storm can be the real constraint on a mountain road. Say if the driveway is steep, long, or shared. A camp roof low to the ground is a different job from a two-story village house with a steep pitch. Moss on a north slope in the woods is a moisture clue. Do not walk a snow-covered roof to find the leak. Tell the caller where the water lands inside.
Give the town, the slope, and whether the problem is lift, ice, a ponding addition, or a load you can see in a sagging line. Active dripping and a stain that only appears in the thaw are different. Stay on the ground. Call the number on this page.