Why it matters

• Dayton's newest master planned neighborhoods generally have strong baseline insulation, but a rapid, large-scale build-out like Sundance Greens or Brayburn Trails can still produce inconsistent ventilation installation from one section of the development to the next.

• Poor attic insulation that lets heat escape and warms the roof deck from underneath.

• Inadequate attic ventilation that keeps the underside of the roof warmer than the outside air.

• Air leaks around recessed lights, attic hatches, vents, and chimneys that let warm household air reach the attic.

• Heavy snowfall followed by freeze thaw cycles which are common through a Minnesota winter.

• Roof design and older or worn roofing materials that let water back up under the shingles once ice has formed.

When it makes sense to act

• If a brand new Dayton home is already forming ice dams. This points specifically to a ventilation installation issue worth having checked while the home is still under any applicable builder warranty.

• Before the warranty window on a new construction Dayton home closes. Addressing an ice dam and its cause while a builder warranty is still active can affect what gets covered.