Construction on the second story of the building that houses the Edgartown Post Office has led to brief post office closures and potential damage to the building, a postal service spokesman said.

Work has been underway at Post Office Square to build five apartments on the second floor of the building that houses the post office and the Martha’s Vineyard Savings Bank. Developer Charles Hajjar received approval for the project by the town and the Martha’s Vineyard Commission in 2014, despite concerns from neighbors about parking and traffic problems.

The project includes building three more apartments on the second story of the adjacent building that houses a Bank of America vestibule and Ocean Breeze bedding. With the roof removed and construction underway, rainfall last Thursday night led to a brief post office closure Friday morning because of water, and the post office was closed again Tuesday morning after more than an inch of rain fell Monday night.

Gene Erez, the contractor working on the project, said Tuesday that despite precautions and carefully following the weather forecast, some water had seeped into the lower story.

U.S. postal service spokesman Steve Doherty said a trailer may become an option. — Mark Lovewell

“Ninety-eight percent of the water was kept out but unfortunately two per cent is still too much,” Mr. Erez said.

On Wednesday afternoon the post office was open as normal. “I’m told that any hazards have been abated, some temporary lighting has been installed and full operations have resumed,” U.S. postal service spokesman Steve Doherty said by email Wednesday, but added that there is damage to the building that will need to be addressed.

About 3,000 post office box holders use the Edgartown post office.

“The logistics of how box holders will get their mail during repairs...are being worked out now,” Mr. Doherty added. He said a trailer is one option and there should be more information available later in the week. The time frame for repairs is uncertain at this time, he said.

The issue of who pays for the repairs will be determined by the terms of the postal service’s lease, he said, and the landlord and contractor are working with the postal service to remedy any issues as swiftly as possible and to minimize customer inconvenience.

“Our first priorities were the safety of our employees and customers and minimizing any inconvenience to our P.O. boxholders,” he said.

The savings bank next door has been functioning throughout the renovation, Mr. Erez and bank employees said.

“At the post office there is minimal water damage, but the concern is water coming through electrical fixtures,” Mr. Erez said. He said the postal service is being properly cautious, and he and his crew are working to make the building water-tight. He said the first phase of construction, including completing the roof, should be done within three or four weeks, with all exterior construction completed within six to eight weeks.

Town building inspector Leonard Jason Jr. said Wednesday he inspected the building last Friday and determined there was minor water spillage that was not dangerous. He was not on the site Tuesday but he did contact the contractor, he said.

“I did ask them to get it tight so they stop the water from going in,” he said. “‘Get your act together’ was the word.”

He said it seems that steps have been taken to prevent future leaks.

“They certainly tried,” he said. “We’ll only know if it rains again.”