Ice Dam Damage Repair and Prevention Visit

Purpose

An ice dam is a heat problem that presents as a roofing problem. The eave repair is warranted work, but it does not touch the cause, so this procedure guarantees two deliverables from one visit: an eave assembly rebuilt to the ice barrier extent the adopted code requires, and a written attic finding naming what put the heat there.

Sell the eave repair alone and the shop has scheduled its own return. The customer will remember being told the roof was fixed, and the next January will look identical.

Scope

Covers the response to ice dam damage on steep-slope shingle roofs, residential and small commercial: safe ice removal, eave assembly rebuild including deck, ice barrier and drip edge, and the attic cause assessment that goes out with it.

Does not cover stopping active water entry, which the emergency tarp and leak-stop visit owns and which runs first. Does not cover attic air sealing or insulation work itself, which is an insulation scope this SOP identifies and quotes but does not perform, or gutter replacement beyond confirming the outlet is clear. Full attic ventilation assessment belongs to its own SOP.

Roles and responsibilities

The dam is downstream of the attic

Heat escaping into the attic warms the upper roof deck enough to melt the underside of the snowpack. That meltwater runs down and reaches the overhang, which has no heated space under it and stays at outdoor temperature, so it refreezes there. The ice builds into a dam, water ponds behind it, and shingles - which shed running water but are not waterproof against standing water - let it under the laps and into the deck, the soffit and the wall below.

The cause is almost always attic bypasses - an open chase, un-sealed top plates, recessed lights, a leaky hatch, ductwork - and only then insulation depth and intake. Air sealing first, then insulation, then ventilation, because a bypass moves far more heat than a thin spot in the insulation does.

The one code number this visit turns on belongs to the edition your jurisdiction has adopted: where there is a history of ice forming along eaves, the IRC requires an ice barrier from the lowest roof edge to a point at least 24 in inside the exterior wall line. That is a horizontal dimension, so on any real overhang the slope distance is longer, and on a low slope longer again.

Procedure

1. Control the ground before anyone touches the roof, and kill power to wet areas. Cordon the full drip line of the affected eave plus a margin for icicle throw, and have the occupant or their electrician turn off circuits serving any room with water at a fixture, a ceiling box or a wall. Acceptance: barricade or tape in place with nobody inside it, circuits confirmed off at the fixture with a tester, breakers marked. Wrong looks like a crew starting a steamer over a walkway people are still using. Stop rule: no ice comes off until the fall zone is clear and stays clear. Hazard: a dam sheds ice in slabs that weigh far more than they look, and water plus energised wiring in a ceiling is the other route - opening a panel is electrical work under 29 CFR 1910.333(b)(2) and goes to a qualified person, not to the roofing crew.

2. Stop active entry first, then set winter access. If water is entering now, the tarp and leak-stop visit runs first. Then set access under the ladder setup standard and the fall protection setup SOP, on a surface that is frozen. This is construction work under 29 CFR Part 1926, not general industry, so the 6 ft fall protection duty at 1926.501(b)(13) applies on a residential roof and any personal fall arrest system used to meet it has to satisfy 1926.502(d): anchorage rated 5,000 lbf per attached worker or engineered to a safety factor of at least two, full body harness, free fall held to 6 ft. Acceptance: entry stopped or confirmed not active, ladder footed on cleared and gritted ground, anchorage set to that rating, everyone connected. Wrong looks like a ladder set on packed snow that becomes a ramp by mid-morning. Stop rule: a roof plane that cannot be walked without a slide stops roof access, and the work happens from a ladder or a lift. Hazard: cold shingles are brittle, so the temperature window in the shingle repair and blend-in standard applies here - the field cracks under a boot, not just under a bar.

3. Remove the ice with low-pressure steam, never with impact. Use a steamer sized for roof work, cut a drain channel first so water behind the dam can escape, then work the dam back. Acceptance: ice off with the shingle surface intact and granules still bonded, water draining freely at the channel. Wrong looks like a hammer, chisel, spade or pressure washer, any of which turn a repair visit into a replacement quote. Stop rule: any tool that fractures shingles is put down, and without steam the visit becomes a channel cut plus containment. Hazard: a steamer burns at the wand and produces carbon monoxide at the burner, so keep the wand off your own body and clear of anyone below, and never run a fuel-fired unit in a garage, an attic or under a soffit. If a de-icing chemical is used, the product label directions bind on rate, placement and contact; sodium chloride corrodes flashing and gutters and kills plantings below.

4. Read the eave assembly once the ice is off. Probe the deck at the eave, look into the soffit, check the fascia, the drip edge and the first three courses, and go inside to look at the wall top plate below. Acceptance: a written extent for damaged deck in linear feet and courses, plus a condition note for soffit, fascia, drip edge and interior. Wrong looks like a scope written while the ice is still on. Stop rule: soft deck extending past the wall line, or wet insulation and framing inside the wall, expands the scope beyond roofing and the customer is told before more is opened. Hazard: saturated soffit and fascia carry mold growth on wetted paper and wood, so wear gloves and eye protection and do not dry-brush the material overhead into your own breathing zone.

5. Rebuild the eave with the ice barrier extent measured, not assumed. Replace damaged deck back to framing centerlines, set the drip edge, then run ice barrier from the roof edge up-slope far enough to reach at least 24 in inside the exterior wall line, lapping courses down-slope. Acceptance: the horizontal overhang measured, the required slope distance computed from it and the roof pitch, and the installed coverage recorded as equal to or greater than that figure. Wrong looks like a single 36 in course on a 24 in overhang. Stop rule: one course that does not reach the computed distance means a second course goes on, lapped down-slope by the membrane manufacturer's stated minimum, before any shingles are laid. Hazard: self-adhered membrane is slick before it is rolled and stiff in the cold, so store it warm, set it from the edge upward, and do not walk on it until it is rolled and bonded.

6. Find the cause in the attic and write it down. Inspect for bypasses at the top plates, chases, recessed lights, the attic hatch and any ductwork; then measure insulation depth over the exterior wall line; then check intake at the soffits. Acceptance: a list of bypasses by location, an insulation depth figure at the eave, and an intake condition note, all in the file. Wrong looks like a repair invoice with no cause line on it. Stop rule: if the attic cannot be entered, that goes in the file as "cause not assessed" rather than being left blank, and a return is offered. Hazard: attic footing is joists only and knob-and-tube or damaged wiring hides under blown insulation, so plank across, carry a light, and do not put a hand into insulation you have not looked into first.

7. Restore, hand over, and prove anything you de-energised works again. Re-lay courses and hand seal per the shingle repair and blend-in standard, clear the gutter and downspout at that eave, have the occupant's electrician restore the step 1 circuits, and reconnect any roof heat cable disconnected for the work. Acceptance: circuits restored and fixtures working, heat cable drawing with its ground-fault device tripping and resetting on test, gutter discharging, tabs tug-tested, and the cause finding handed over in writing with the invoice. Wrong looks like a crew leaving with a breaker still off and nobody told. Stop rule: heat cable that will not energise, or that trips its protection, stays off and goes to an electrician - it is fixed outdoor de-icing equipment under NEC Article 426 as adopted locally, not a roofing accessory. Hazard: this step puts power and a heat source back into a wet assembly, so the ground-fault test is the verification, not a formality.

The record this produces

An ice dam entry carrying: whether entry was active and whether the tarp SOP ran first; circuits isolated and how confirmed; removal method and any chemical used, by its label name; damaged deck extent; soffit, fascia and drip edge condition; the measured horizontal overhang, the computed required slope distance and the installed ice barrier coverage; the bypass list, insulation depth at the eave and intake condition; and the heat cable and circuit restoration results.

The estimator reads the bypass list, because that is the quote that stops this recurring. The office reads the cause line when the customer calls next winter.

Worked pass: 24 ft eave, 4:12 slope, 24 in overhang, 1970s ranch

Step 1: drip line cordoned 8 ft out, bedroom and hall circuits off and confirmed dead at the fixtures. Step 2: no active entry today, so the tarp SOP does not run; ladder footed on gritted ground, anchorage set. Step 3: steam only, drain channel cut first, dam worked back with the shingle surface intact.

Step 4: deck soft across the full 24 ft eave and up about 3 ft, so roughly 72 sq ft to replace; soffit saturated on 16 ft of it; drip edge corroded; interior top plate damp but framing sound.

Step 5 fails on its first plan. The crew intended one 36 in course of ice barrier. The overhang measures 24 in horizontally from the wall face, and the code extent is 24 in inside the wall line, so the horizontal distance to be covered is 24 plus 24, or 48 in. At 4:12 the slope factor is the square root of 1 plus 4 over 12 squared, which is 1.054, so the slope distance is 48 times 1.054, or 50.6 in. One 36 in course is 14.6 in short. The stop rule fires: a second course goes on, lapped down-slope by 3 in, giving 36 plus 33, or 69 in of coverage, 18.4 in beyond the requirement. Two courses along a 24 ft eave is 48 linear feet of membrane.

Step 6: the attic shows four un-sealed bypasses - an open plumbing chase, two recessed lights with no airtight rating, and an attic hatch with no gasket - insulation depth over the exterior wall line measured at 4 in where the rest of the attic runs deeper, and soffit intake blocked by that insulation with no baffles. Step 7: courses re-laid and hand sealed, gutter cleared and discharging, circuits restored by the customer's electrician, no heat cable present.

The 14.6 in shortfall is the number worth keeping. Nobody would have seen it on the finished roof, the crew would have believed they installed an ice barrier, and the first inch of ponding above the wall line would have been sitting on felt.

References

• 29 CFR 1910.333(b)(2), electrical safety-related work practices for qualified persons, which governs the circuit isolation this procedure requires but does not perform
• 29 CFR 1926.501(b)(13) and 1926.502(d), the fall protection duty and arrest criteria governing roof access for this work
• IRC Chapter 9, in the edition your jurisdiction has adopted, for the ice barrier requirement and the distance inside the exterior wall line it must reach
• NEC Article 426, fixed outdoor de-icing and snow-melting equipment, as adopted by your jurisdiction, which governs any roof heat cable on site
• See related: the emergency tarp and leak-stop visit SOP, the attic ventilation assessment SOP, the shingle repair and blend-in standard, and the gutter integration SOP