A U.S. District Court judge, deciding a 10-year-old class action civil rights lawsuit brought by eight black construction workers, ruled here yesterday that they were deprived of or delayed in obtaining union membership in a major Washington construction union because of their race.

Judge John Garrett Penn said evidence presented "demonstrates persistent, pervasive and intentional discrimination" by Iron Workers Reinforced Rodmen Local 201 and others against black rodmen. Rodmen handle and place steel reinforcing rods.

As a result, the eight workers received significantly less work than their white counterparts, and they are entitled to back pay, Penn said. The amounts are to be determined at a later hearing.

It was not immediately clear last night whether unnamed workers in whose behalf the suit was also filed would be entitled to monetary compensation.

In addition to finding evidence of discrimination by Local 201, Penn found that the international union with which the local was affiliated "knew of the discriminatory conduct" and permitted it to continue.

The eight workers who brought the case, and the class of "similarly situated" unnamed persons also listed as bringing the suit, were also discriminated against by the Construction Contractors Council (CCC), an employer group, Penn wrote.

He said the contractors council "should have known of the racial discrimination" that occurred.

Neither representatives of the organizations nor their lawyers could be reached for comment last night.

The named workers who brought the case were Ernest Bellamy, Van Edward Lewis, Jesse Berger, Randolph Jackson, Tommy Kirkland, Ronald Tucker, Willie Lee McMillian and Garrett Simmons.

They were represented by John Oberdorfer and John Dienelt in behalf of the Washington Lawyers Committee for Civil Rights, which in a news release described the matter as a "major class action, equal opportunity case."

According to Penn's opinion, the union acts as an employment agency in referring rodmen to contractors in the contractors council. Preference goes to those who have passed a journeyman's examination; and, in practice, the preferred group consists of Local 201 members, Penn said.

In recent years, he said, rodmen under age 31 have been unable to qualify for the journeyman examination without completing an apprenticeship program. Admission to the program requires a high school diploma.

Citing data showing black men less likely to have a diploma, Penn, whose opinion leaned heavily on statistical evidence, called the requirement discriminatory under Title VII of the 1964 Civil Rights Act and other federal law.

In the three years before the suit was filed, Penn said, almost three-quarters of the experienced rodmen over 31 and not in the union were black. After 1971, he said, they faced "yet another barrier" to membership: a requirement that those 31 or over finish a two-year training program to qualify for the exam.

Penn said that requiring blacks with long experience to enter and complete the program, which entailed a loss in wages, "perpetuated the denial of equal employment opportunities" to them.

Penn said that those who brought the suit "are suffering irreparable harm" and "are entitled to declaratory and injunctive relief."