Bob Wycoff prayed for rain all last week, unusual for a man who makes his living pouring concrete.

But these are not normal times in the Northern Virginia building trades. With the Washington area's largest concrete supplier, Virginia Concrete Co., crippled by a strike, scores of builders are adjusting their prayers. The strike has forced delays at numerous job sites and threatens to paralyze the booming construction industry here.

"Rain -- that was my only hope," said Wycoff, who specializes in building foundations for homes. If it rained, he said, some big concrete users would cancel their pours and he'd have a chance to get concrete for the first time in days.

On Friday, the heavens obliged. Under skies the color of wet cement, Wycoff got six trucks of concrete, half the number he'd want on a typical spring day.

"This strike is killing me, it's ridiculous," said Wycoff, who was on the phone for three hours Friday morning before he found anyone able to give him a truckload. "It's a pain trying to work when you don't have anything to work with."

Because of the two-week-old strike, 10 of Virginia Concrete's 11 mixing plants are shut down. At least 175 of its 201 mixers are idle.

The strike has pinched large and small users alike, but thus far it has hurt specialty contractors such as Wycoff particularly hard. His whole business consists of setting up frames for residential basement walls and pouring the concrete that becomes those walls. No concrete, no work.

The strike by 220 Teamsters against Virginia Concrete comes in the midst of what builders say is probably the biggest construction boom in Northern Virginia in the last decade, and at a time of year when most construction projects are going full tilt.

Negotiators met for several hours Thursday, but no new talks are scheduled in the strike in which pay, benefits and job security are the sticking points. If the strike lasts until the end of this week, said construction project managers interviewed last week, it will cause massive delays and layoffs.

"I just can't believe they're doing this," Wycoff said of the Teamsters. "I've known these guys for 20 years. It was so bad out here for so long. I got to make money while the making's good, and they do, too!"

Virginia Concrete did have about 25 trucks on the road last week, driven by management personnel, but small jobbers such as Wycoff, with pours in difficult, muddy areas, were low on the company's list.

While Wycoff couldn't beg a single mixer from Virginia Concrete, Tom Cox saw 27 truckfuls at his job site one day last week. Cox, who is in charge of construction on the first of three 17-story Tycon Tower office buildings at Tysons Corner, wasn't satisfied with that.

"Hell, no," he said with an enormous grin. "Why, you should've been here half an hour ago. I was giving [Virginia Concrete] an earful of stuff over the telephone you couldn't have printed."

Cox's men were pouring the floor slab for the ninth story, and the concrete wasn't coming fast enough. "I want it in here at 50 yards [six trucks] an hour, and they were only giving me 30 yards an hour," he said. "It's costing me an arm and a leg . . . ."

While the mixers were rumbling onto Cox's job site about 3 p.m., he took a call from a dispatcher at Virginia Concrete.

"She said she had one little guy [who] had been waiting since 7:30 [a.m.] for a single mixer of concrete, and she wanted to know would I break one of my 27 trucks loose for him." Cox flashes the big grin again.

"Are you kidding?" he continued. "Course I told her no. Man's been waiting since 7:30 for one truck, he doesn't really need that concrete. I really need it."

With the leverage of a big project and big money, Cox has been able to get concrete. During the first week, he also was able to juggle tasks to avoid needing the concrete as desperately as some small contractors such as Wycoff.

But the juggling can't go on much longer, and for projects like Cox's, this week will be the key.

Virginia Concrete is supposed to pour the second half of the ninth floor today, but it can't guarantee the concrete. Cox has lined up concrete from another supplier, Herndon Concrete, in case Virginia falls through.

"And if Herndon does one pour here, they've got the job," Cox said.

How much concrete is that? "Oh, about 15,000 yards," said Cox -- nearly 2,000 truckloads. "That's why I'm getting concrete," said Cox, flashing a grin once more.