Noah had three sons, but if they were so upset with him that they cut off his Peter Pecker after the flood was over, I doubt they were very helpful during the pre-flood efforts.
Looking for guidance on all this I turn to a personal wise man, Randal Graves, video rental salesman in the movie "Clerks," directed by Kevin Smith.
Here is what he had to say when discussing the second Death Star, in the Return of the Jedi:
Randal: So they build another Death Star, right?
Dante: Yeah.
Randal: Now the first one they built was completed and fully operational before the Rebels destroyed it.
Dante: Luke blew it up. Give credit where it's due.
Randal:And the second one was still being built when they blew it up.
Dante: Compliments of Lando Calrissian.
Randal: Something just never sat right with me the second time they destroyed it. I could never put my finger on it-something just wasn't right.
Dante: And you figured it out?
Randal: Well, the thing is, the first Death Star was manned by the Imperial army-storm troopers, dignitaries- the only people onboard were Imperials.
Dante: Basically.
Randal: So when they blew it up, no prob. Evil is punished.
Dante: And the second time around...?
Randal: The second time around, it wasn't even finished yet. They were still under construction.
Dante: So?
Randal: A construction job of that magnitude would require a helluva lot more manpower than the Imperial army had to offer. I'll bet there were independent contractors working on that thing: plumbers, aluminum siders, roofers.
Dante: Not just Imperials, is what you're getting at.
Randal: Exactly. In order to get it built quickly and quietly they'd hire anybody who could do the job. Do you think the average storm trooper knows how to install a toilet main? All they know is killing and white uniforms.
Dante: All right, so even if independent contractors are working on the Death Star, why are you uneasy with its destruction?
Randal: All those innocent contractors hired to do a job were killed- casualties of a war they had nothing to do with. ... All right, look-you're a roofer, and some juicy government contract comes your way; you got the wife and kids and the two-story in suburbia-this is a government contract, which means all sorts of benefits. All of a sudden these left-wing militants blast you with lasers and wipe out everyone within a three-mile radius. You didn't ask for that. You have no personal politics. You're just trying to scrape out a living.
So even though Noah was the only holy man left on Earth, what about all the people that he would need to build an ark that would last for an entire year, who then got washed away?