President Donald Trump led reporters on a tour of the White House construction site on Tuesday, unveiling the new granite helipad on the South Lawn and holding forth at length on grades of stone, sightlines and square footage, five months into a war with Iran and days after asking the Supreme Court to let him resume work on a ballroom a federal appeals court ordered stopped.

The president summoned the White House press pool for the impromptu media availability to boast about the changes he has made to the Southern entrance to the building on Wednesday, during the time his public schedule had reserved for a “policy meeting.”

Instead of discussing policy with aides, he began to boast to the assembled cameras and journalists about the comparative attributes of granite versus asphalt for the White House driveway, wax about the living properties of grass and talk up his own prowess at renovation projects.

"I was very good at real estate, like maybe the best in a lot of ways, and I love construction," the president said. "I love seeing things properly taken care of."

Trump spent the bulk of the appearance on the stone itself. The white granite, quarried in California, is cut in a radial pattern — "every stone is two degrees rounded," he said — and laid four inches thick, rather than the inch or inch and a half he said is standard. He returned repeatedly to its rated compressive strength of 35,000 pounds per square inch, against roughly 5,000 for hard concrete.

"This granite has a million-year life," he said. "You'll never see a crack in this granite. I will go on the line. So in 10 years, if you see a crack, you'll say, 'Well, Trump just said you'll never see a crack.'"

He also said the helipad, which will bear a hand-carved seal, is "very close to being finished" and could be completed by the time Chinese president Xi Jinping arrives in Washington for a state visit next month.

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