LACONIA — City officials yesterday closed the downtown parking garage until further notice after an inspection revealed that a number of steel beams and joints supporting the ramps have been compromised by corrosion.
Bob Durfee, an engineer with Dubois & KIng, Inc., said yesterday that Paul Moynihan, director of public works, had asked the firm to make an assessment of the parking garage, which began last week. He said that he expected to find some damage that would require repair, but did not anticipate the extensive corrosion he found. The most severe damage, he explained, is to the ramps, where the concentration of road salt is greatest.
Moynihan said that on the strength of Durfee's findings the ramps between the middle and top deck of the garage were closed last Wednesday and, after further inspection, the remaining ramps were closed and the garage evacuated early Monday evening.
Durfee said that the garage, which was built in 1973, with its exposed steel supporting ramps and decks is the only one of its kind he has encountered in the northeast — where reinforced concrete is preferred for its capacity to withstand constant exposure to road salt during the winter. Moynihan said that crews seek to minimize the amount of salt used on the ramps.
Durfee said that the next step will be to test the strength of the steel where the corrosion is most severe, which is done by measuring the amount of steel lost and calculating the strength of what remains, and identify the necessary repairs.
Moynihan said that once the assessment is complete the necessary repairs required to reopen the garage would be undertaken as soon as possible. He noted that R.M. Piper, Inc. of Plymouth, the firm that just finished reconstructing the Main Street Bridge, is prepared to make the repairs and Bob Ayers, who supervised the bridge project, joined Durfee and Moynihan at the garage yesterday. He indicated that repairs represented "not less than a two week project and with a very real potential of the garage not reopening for four weeks".
There are approximately 200 parking spaces in the garage. The ground level, together with the southerly third of the middle and top decks and southerly stairwell, are privately owned while the remainder of the garage is owned by the city, which holds easements to cross the ground to the ramps and stairway.
While the parking garage remains closed overnight and two-hour parking restrictions in the downtown area will not be enforced by city police.
CAPTION: Corrosion, caused by more than four decades of exposure road salt, has eaten through the steel at a joint in the underpinnings of one of the ramps at the parking garage. "We have a few places like that," said Paul Moynihan, director of public works. (Laconia Daily Sun photo/Michael Kitch)