The U.S. housing sector is falling apart, and the Federal Reserve is all but ignoring the damage as it prepares for what many expect to be three rate hikes in 2019, CNBC's Jim Cramer warned Friday.

"The housing sector's a disaster," Cramer said on "Closing Bell." "We're building about half the houses we did when the country had half the people, and we still can't sell them. KB Home does a huge amount of housing in California. They can't sell them."

U.S. homebuilding fell more drastically than expected in September, according to the Commerce Department. Housing starts dropped 5.3 percent after rising slightly in August. Existing home sales also dropped the most in over two years as rising material costs crimped supply and rising mortgage rates deterred prospective buyers.

The Fed's interest rate hikes have contributed to the surge in mortgage rates, which in October jumped above 5 percent. The central bank has said it plans to hike rates in December of this year — a move Cramer supports — and three more times in 2019.

"I favor a rate hike, and then I'd like to wait. In what world is that irrational?" Cramer said Friday. "Affordability's gotten out of control. [The Fed members] know that. We have affordability data. But they don't want to focus on the things they should."

That lack of rigor is leading the Fed to make decisions that are "not safe" and "irresponsible" when it comes to the U.S. economy, the "Mad Money" host said, echoing his earlier point that the Fed needs to do more homework.

"We shouldn't look upon them as if they have great information. They had such bad information in 2007," Cramer said. "They have this judgment that the economy's great. It's an irresponsible, non-empirical judgment. It's anecdotal. It has not a lot of homework. And I favor rigor. I think rigor is what matters, sophistication and rigor. And they're unsophisticated, and they're non-rigorous, and I would rip up their homework and tell them to go home."