EAST MILLINOCKET, Maine — Voters will decide during a special referendum on July 18 whether to repair the roof of Schenck High and Opal Myrick Elementary schools for about $1.87 million, officials said Wednesday.

The Board of Selectmen voted 5-0 on Monday to set the date and to approve the language of the warrant voters will review as they cast their ballots, Chairman Clint Linscott said.

The special referendum will be preceded by an informational meeting on July 8. Hopefully by then the state’s budget will be settled enough to give residents a clearer view of the project’s impact upon their taxes, Selectman Mark Scally said.

Previous estimates have indicated that the project would increase the town’s property tax rate from $23.33 per $1,000 of valuation to $30 or $31, but that is not finalized, Scally said.

“Residents have to vote. [The two schools’ building] is a crucial part of the town and the town is kind of split here,” Scally said Wednesday.

Selectmen and their budget committee voted 3-2 and 4-0 late last month to recommend against the project, while the East Millinocket School Committee voted 3-2 to recommend supporting it. State law requires the recommendations be printed on the ballots.

In almost continuously changing budget and cost estimates, the school board seeks what is now $1.87 million in repairs to its leaky roof, gym floor and other elements. Repair estimates have jumped from $187,000 to $2.1 million as alternate possibilities and unfinished town and state budgets have made solid numbers difficult to develop.

School board members have said that the education offered at Schenck, the town’s only active school building, is excellent and essential to the town’s economic development prospects. They fear that not repairing the roof would leave the town with a dead building and increase the town’s economic and population declines.

The town’s population has dropped from 2,557 in the 1970 census to 1,723 in 2010. East Millinocket’s projected student population in September is 209 students, the lowest in town history.

The building is 1957 vintage. The roof repair is part of several increased costs that selectmen expect to spur a property tax increase from 23.33 mills to about 44 mills next year. It is part of a larger question — whether to close the school or repair the roof and possibly commit later to as much as $7 million in building repairs to keep students in East Millinocket.

An eight mill tax increase would mean that a property worth $50,000 taxed $1,166 this year would be taxed $1,566 effective July 1, when the new fiscal year begins. A property tax increase to 44 mills would mean property tax on a $50,000 property would climb from $1,166 to $2,200 annually.

The Maine Department of Education had indicated it would pay about $636,000 of the project when it was set at $2.1 million, officials have said. It was unclear Wednesday whether the state’s payment would diminish with the new price. Superintendent Quenten Clark did not immediately return a telephone message and email seeking comment.

The building serves about 280 students from East Millinocket, Medway and Woodville, including Opal Myrick, which moved into a wing in 2011.

School board Chairman Dan Byron said that the school budget for the 2013-14 fiscal year, which begins July 1, will increase by about $200,000 over this year’s, but that number is far from finalized. Besides the need for voters to approve it before it is final, the budget will likely change in the next few days, he said.

“I think it will be fluid,” Byron said Wednesday.

The East Millinocket Teachers’ Association’s leadership has said it supports keeping the school open, but its members have not yet offered concessions that might aid that effort, Byron said. If they did, “that would be a nice gesture,” he said.

According to a copy of the union’s contract, some salary levels will drop $10 to $2,400 starting July 1. A few others will rise. Exactly why was not immediately apparent. Byron said it might have to do with increasing health care costs and increased health plan contributions by union members.

He referred comment to Superintendent Quenten Clark, who did not return telephone and email messages.