Frozen ice on top of roofs can cause some serious trouble in New England. Since temperatures can be as high as 60 degrees and then drop the next day to 30 degrees, snow will melt quickly and enable mold growth along with roof deterioration. Water can also go through attics, dormers, and wall cavities and then into the basement and first floor.
To detect mold, simply check for water stains and dark spots. Look for stains and mold on the surfaces of the ceiling, carpets, attic, attic plywood sheathing and floor joist. Also, make sure to look for moisture or a humidity level of 65%.
If you smell unusually unpleasant odors, this is usually a pretty good indicator of mold. Wall cavities and insulation could be wet on the inside of the walls and dry on the outside. High relative humidity could be the main issue.