Guide
Ice dams on steep north-facing Bergen County roofs
Written by Ultra Power Construction. The credentials page states that this contractor is licensed and insured in New Jersey and lists GAF and Owens Corning programs. Updated 2026-09-27.
Ice dams show up on steep, north-facing roofs in Cresskill, Closter, Old Tappan, Norwood, and neighboring northern Bergen towns. The roof membrane helps. The attic heat is the cause.
- How the dam forms
- What to specify on the roof
- What to specify in the attic
How the dam forms
Attic air warms the deck, snow melts, and water refreezes at the cold eave. It backs up under shingles and into the wall. The ceiling stain is often at the plate line.
What to specify on the roof
Ice-and-water membrane from the eave up past the interior wall line, and through valleys. Say the distance in feet for this pitch. A single row on a low slope does not reach the wall.
What to specify in the attic
Open soffit intake, a clear path under the deck, and enough insulation on the ceiling rather than stuffed against the roof. A ridge vent over blocked soffits will not stop the dam. Town pages for Closter and Old Tappan cover the local versions.