Administrators and teachers in the Kent School District negotiated much of Friday and all day Saturday, but by Saturday evening had not yet reached an agreement that could end a 17-day teachers strike.

Administrators and teachers in the Kent School District negotiated much of Friday and all day Saturday, but by Saturday evening they had not reached an agreement that could end a 17-day teachers strike.

The district and the union now agree on the maximum number of students that middle- and high-school teachers should instruct before they get some assistance. But the Kent Education Association wants teachers to get more help than the district has proposed, said spokesman Dale Folkerts.

And district negotiators said they were surprised Saturday by a new union proposal on elementary-class sizes that would set an even lower level for the point at which teachers would get extra help.

The two sides also have yet to agree on class-size limits for elementary classes, especially in kindergarten, and how many meetings teachers should be required to attend before and after school.

Talks were expected to continue through the evening.

King County Superior Court Judge Andrea Darvas ruled Thursday that teachers who don’t return to work on Monday will face fines of $200 per day each, retroactive to Sept. 8. It’s not clear whether the district’s 1,700 teachers will obey.

Still, district administrators have announced school will start Tuesday, hoping teachers will return whether or not an agreement is reached. If they don’t, “we’ll cross that bridge when we come to it,” said Becky Hanks, district spokeswoman.

The two sides started negotiating this spring but reached an impasse in mid-August and have been working through a mediator ever since.

This is the first time teachers have gone on strike in Kent, which has nearly 27,000 students and is the state’s fourth-largest district.

Class size has been the most contentious issue, with teachers saying many of their classes are too crowded, especially when many students have health or behavior problems, or are learning English.

Teachers say the district can afford to lower class size, pointing to the $21 million in a reserve fund.

District officials, however, have said $8.5 million of that amount already is committed to specific purposes — everything from workers’ compensation claims to books teachers have ordered. The other $12.5 million, they say, is the minimum savings required by School Board policy.

Nearby districts keep a lower percentage of their budgets in reserve, but school-finance experts say there is no rule of thumb for how much savings districts should have because their financial circumstances vary.

Kent administrators also dispute the union’s class-size claims, saying the vast majority of the district’s classes are much smaller than the maximum allowed under the old contract, which has expired.

Linda Shaw: 206-464-2359 or lshaw@seattletimes.com