Ice damsIce along the eaves of Colonia roofs
Ice Dams in Colonia, NJ
Ice dams in Colonia: ice piling up along the eave, icicles over a window, a stain that shows after the thaw.
Call (732) 568-2812, point out where the ice sits and where water enters, and the contractor arranges the look.
Leave it and get help if
- A sheet of ice or heavy icicles overhang the front step or a path: steer family and animals away from the spot below, and dial 911 if a chunk has hit somebody.
- A fixture is dripping meltwater, or the ceiling has swollen with it: leave the room, do not handle the switch, and dial 911 from a dry spot.
- Someone is on a ladder or the roof chipping at ice: have them come down. UMass writes that chipping does more harm than good; dial 911 for a fall.
- A wire is down, or a branch heavy with ice rests on the lines: treat it as live, keep well away, then call 911 and the electric company.
What to ask about ice and the attic
Is the plan to treat the ice or the cause?
UMass calls ice belts and self-adhering membranes a band-aid, and names a roof held at outdoor temperature as the lasting answer.
Will the attic be air sealed before insulation goes in?
UMass lists wire and plumbing penetrations, light fixtures, attic hatches, chimneys and bath fans as the places where warm air gets in.
How deep will the insulation be at the eaves?
UMass gives roughly R-38 for northern homes, continuous over the exterior walls.
Is there a clear path from soffit to ridge?
UMass names soffit-to-ridge ventilation, with a 2-inch air channel above the insulation, as the most effective approach.
What decides how big an ice-dam job gets
A house with thick insulation and a tight ceiling may need little beyond a look. One with gaps around chimneys and light fixtures and thin insulation near the eaves needs air sealing first, then insulation, then ventilation, and each is a separate line on a quote.
Wet insulation and damp sheathing found after a dam add repair work. Ask for each step itemized; no figures belong on this page.
What it looks like
- A broad shelf of ice hugging the eave with snow still piled above it
- Long icicles hanging over a window, a door or the walkway
- A ceiling or wall stain that shows up during a thaw
- Water marks beside an exterior door or window after the snow melts
- Wet insulation or damp roof boards at the attic hatch once the ice is gone
Ice at the edge, snow above, a window below
The picture shows snow on a roof edge, a heavy ridge of ice running along the eave and long icicles hanging over a window. The ridge is the dam, and the icicles are meltwater dripping over it.
UMass names three ingredients: snow, warmth that melts it, and cold that refreezes the meltwater. Heat from the house warms the upper roof, and the overhang stays cold, so the water freezes where the roof ends.
What a roofer can look at
Call (732) 568-2812, say where the ice builds, where the water comes in and whether ice is still on the roof, and a roofer can arrange a visit.
Looking at the eaves and the roof edge for lifted shingles, bent metal and torn gutters.
Reading the attic side: the depth of insulation near the eaves, frost or stains on the roof boards, and gaps around chimneys, hatches and light fixtures.
Checking the soffit and ridge vents for blockage.
Looking for hidden damage after a dam: wet insulation, damp sheathing and moisture inside the wall.
Explaining the options in order: first steps for this winter, repairs, and longer-term work such as air sealing and insulation.
Asked at the door
How urgent is a ridge of ice at the eave?
Not by itself. Ice hanging over an entry, a ceiling that sags or water reaching a fixture means getting clear and calling 911. A stain or drip during a thaw means call (732) 568-2812 this week. Ice with no leak can wait for the thaw, with dated photos taken from the ground.
Will a heat cable or chipping the ice solve it?
UMass says a heat cable creates an ice dam just above it and that chipping does more harm than good. Careful raking of snow from the roof helps, and self-adhering membrane under the shingles is a backup it calls a band-aid. The lasting remedy it names is a roof held at outdoor temperature.
Do Iselin and Edison roofs get ice dams too?
Same weather, same causes. At the Newark gauge, January averages 32.8 F with 22.6 nights at or below freezing. The Iselin page and the Edison page are on the same line as Colonia; call (732) 568-2812 with the address.
Soffit, baffle, ridge vent and membrane: the cold-roof parts
- Eave
- The overhang, which stays cold.
- Soffit vent
- An intake on the underside of the overhang that lets outside air in.
- Baffle
- A channel that keeps insulation from blocking that airflow; UMass calls for a 2-inch air channel between the insulation and the roof boards.
- Ridge vent
- The outlet along the top of the roof; UMass names a baffled ridge vent with continuous soffit vents.
- Ice barrier
- A self-adhering membrane under the shingles at the eave, which UMass treats as a backup layer.
Looks you can take
- From the ground, note where the ice builds up: all along one side, or only above a heated space such as a kitchen or a bath.
- Photograph the ridge and the icicles from a safe distance with the date, and again after the thaw.
- At the attic hatch with a flashlight, look for frost on the roof boards, damp insulation and thin spots in the insulation near the eaves.
- After the ice is gone, look for stains on ceilings and at the tops of exterior walls; UMass notes that wet insulation and damp sheathing can follow a dam.
What the state bulletin says about an ice barrier
A state construction bulletin, 07-3, applies the ice-barrier rule where the average January temperature is 25 F or colder, which in New Jersey means Sussex County. Colonia is not in Sussex County. A roofer may still put a membrane at the eaves. Under the 2018 notice, repairs to roof covering on one- and two-family houses that share no wall with another building count as ordinary maintenance; offices and numbers are under Papers to ask for.
Notes from the sources
- UMass Amherst Building and Construction Technology, Preventing ice dams (P. Fisette)
- NJ Department of Community Affairs, Code bulletin 07-3 on ice barrier underlayment
- NOAA NCEI, 1991-2020 monthly normals, Newark Liberty International Airport (USW00014734)
- National Weather Service Mount Holly, January 2016 winter storm snowfall report
- National Weather Service Mount Holly, event review of 16-17 January 2022
- U.S. Department of Energy, Repairing Roofs and Ceilings technical brief
- NIOSH, Ladder safety (CDC archive, reviewed 1 March 2024)
- PSE&G, Downed power lines (electric safety)
Checked 1 Nov 2026
Calling in
Jot down the address, how old you think the roof is and what you can see from the lawn. Then call (732) 568-2812. In a rental, the landlord or the property manager is who you phone first. Calls cover Colonia, Iselin and Edison.
