My house has a basement, and I can see the pipes under the floor, but I also have a water stain on my bathroom ceiling, and I can see icicles hanging from the roof’s overhang outside the bathroom window. Do I need a plumber?
I cannot think of a situation where a house with a basement would have pipes in the attic unless the home has a fire-suppression system. What you most likely have are ice dams on the roof.
When it’s so cold outside that the snow on the roof cannot melt, the snow near the edge of the roof receives heat from the room below or from an unvented bath fan. As the underside of the snow melts and runs down the roof, it meets the still-frozen snow pack or ice dam and, with nowhere to go, the ice water seeps under the roof shingles and drips to the room below or to the roof’s overhang.
Ice damming is uncommon in milder climates, but in the colder regions of the country, roofers know to place a layer of Ice and Water Shield or similar rubberized materials under the shingles. Starting at the roof’s edge and working upward, the ice shield covers at least the first four or more feet of the roof’s decking.
To prevent ice dams in the future, you need to make sure the bath fan is vented all the way to the exterior and does not vent to the attic.
You also need to ensure that the ceiling is insulated all the way to the edge of the attic and that there is a small space above the insulation to provide ventilation. The insulation should never touch the underside of the roof’s decking. With a low-pitched roof it may be impossible to reach the edge of the roof from the attic.
The other option would be to install an ice shield under the shingles. If the shingles are in a good condition, an ice shield can be installed without having to replace all the shingles. An experienced roofer can remove the first few feet of shingles, install the ice shield and replace the existing shingles if they are still pliable.
This has been an unusually cold winter in the Midwest, and I do not expect this to be a yearly event in the milder climates. But adding insulation and ventilation will help lower your energy loss.