CEDAR FALLS (MCT) — Crack ! Bang! Thud!
Northeast Iowans are hearing mysterious loud noises outside their homes this winter. One homeowner said it sounded like “the whole side of the house was going to split apart.”
Though hard to pin down, building officials say the noises are most likely harmless. Construction experts believe several things could make the sounds, such as ice popping, and to a lesser extent, ground that’s shifting due to freezing and thawing.
Dave Bartlett, owner of Dave Bartlett Construction in Cedar Falls, said the noises generally occur when the mercury drops to around zero or below.
“I’ve heard it, too. All of a sudden there’s a boom,” he said.
When ice builds up on a roof, Bartlett said it expands when it gets extremely cold. The ice cracks under the pressure.
Matt Freet, a project manager with Magee Construction in Cedar Falls, said strange noises coming from inside or outside a home do happen during the winter. Expanding, popping ice is the most likely culprit, he said, but not the only reason. Ice chunks could fall off a house and hit a deck or something else hard.
Lumber tends to lose moisture, especially in newer homes, and contract. As a result, creaking noises could occur or nails or screws could pop out.
Freezing and thawing can cause the ground to heave or shift, especially in new homes where fill material was needed and isn’t totally settled, making structures like decks to creak.
“I’d probably say the ground is frozen so hard it’s shifting, but I can’t say for sure,” said Craig Etjen, Parkersburg building inspector.
Northeast Iowa has experienced significant snow, rain and temperature fluctuations ranging from near 40 to 20 below zero during the past two months. For example, December 2009 will rank as the second wettest and second snowiest on record in terms of statewide averages at 2.61 inches and 22.2 inches, respectively.
While noises are probably harmless, contractors say ice dams on roofs can be a problem. Ice at the edge of a roof line can back up under shingles and cause water damage. Poor insulation is the main culprit.
Bartlett advises people to call an expert to take care of ice problems.
“Don’t go up with a ice pick or hatchet and start swinging. You’ll take shingles right with it,” Bartlett said. “We do it very carefully.”