Ice dam repair in Des Moines

Why Des Moines roofs get ice dams

An ice dam forms when the upper roof is warm enough to melt snow and the eave is cold enough to refreeze it. The melt runs down under the snowpack, hits the overhang — which has no warm house under it — and freezes into a ridge. The next melt pools behind the ridge, and because shingles are designed to shed water running downhill, not sitting in a pool, it backs up under them and into the wall.

Des Moines gets about 35 inches of snow a year and spends most of December through February crossing 32°F every few days. That's the recipe. The houses that get it worst are the city's 1920s–50s stock — Beaverdale, Drake, Highland Park, the Waveland Park bungalows — with low-pitched roofs, tiny attics, no soffit vents, recessed lights and bath fans dumping warm air straight into the rafters. But a 2010 Johnston two-story with a cathedral ceiling over the great room and a bath fan that vents into the attic will do it just as well.

Ice dam removal

Ice dam roof repair in Des Moines starts with getting the dam off without wrecking the shingles.

Steam. We use a low-pressure steamer that cuts channels through the ice and melts the dam off the roof. It's the only method that doesn't damage shingles. $400–$1,000 for most eaves, depending on how much ice there is and how many roof edges are involved.

What we don't do. No hammers, no ice picks, no hot-water pressure washers, no rock salt in a stocking. Every one of those tears granules off or splits shingles, and you'll pay for a new roof edge in April.

Roof raking — pulling the snow off the bottom four feet of the roof from the ground — is what you do between storms to keep the dam from forming. A $40 roof rake at the hardware store is the cheapest roofing tool in Iowa.

Repairing what the dam did

Once the ice is gone, we look at what it damaged. The usual list, and typical prices:

• Water-stained or lifted shingles on the first three or four courses: $300–$800 to re-lay with ice-and-water membrane underneath
• Rotted fascia and the first sheet of decking behind a gutter that has iced up every winter: $500–$1,500
• Gutters pulled loose or bent by the ice load: re-hang or replace the run
• Interior drywall, insulation and paint — we'll document it for the insurer; ice dam water damage is usually a covered loss, though the cause isn't

If the roof is due anyway, this is the moment to plan a replacement with membrane run two full courses up the eave, which Iowa code requires and which most 1990s roofs don't have.

Stopping it: the attic is the fix

A roof leak from an ice dam is a symptom. The disease is warm air getting into the attic. Every ice dam job we do ends with an attic inspection, because the prevention work costs less than the second steam call.

1. Air-seal the attic floor. Foam around every wire and pipe penetration, caulk the top plates, gasket the attic hatch, box recessed lights with fire-rated covers. This is the single most effective thing, and the most skipped.
2. Vent the bath fans and dryer outside. Through the roof or the gable, never into the attic. A family of four puts gallons of warm, wet air into the attic every day through a fan that stops at the insulation.
3. Bring insulation up to R-49. Central Iowa is climate zone 5; most 1950s attics have a third of that. Check MidAmerican Energy's current rebate list before you buy.
4. Balance the ventilation. Soffit intake and ridge exhaust, with baffles so the insulation doesn't block the soffits. Roof ventilation in Des Moines is neglected on old houses because the soffits are narrow; there are low-profile solutions.
5. Heat cables as a last resort for a specific problem eave — a north-facing valley or a low-pitched porch roof — not as the whole plan. They cost money to run and hide the underlying issue.

Our seasonal guide on ice dams and how to stop them covers what you can do yourself before the first snow. If the leak is showing up without any ice at all, it may be condensation, not a leak.