The six-year Salt Lake Temple renovation project reached a momentous halfway point on Tuesday with a massive infusion of concrete for the new, earthquake-resistant foundation.

More than 150 ready-mix concrete trucks began rolling up to the Temple Square worksite just after midnight to pour out concrete for 6-foot-deep footings all around the temple’s west tower, part of a new seismic foundation intended to protect the historic pioneer temple from future earthquakes.

The temple “stands in stately majesty as a beacon of light to all the world,” according to President Russell M. Nelson, president of The Church of Jesus Christ of Latter-day Saints, and Tuesday’s concrete pour is a significant phase in the renovation of the iconic temple.

“We’ve been preparing to build this foundation for three years,” said Andy Kirby, director of historic temple renovations. “This concrete creates the footing for the new foundation for the Salt Lake Temple,” he said Tuesday.

One visual underscored the importance of Tuesday’s milestone. The stairway to the temple’s photogenic west door now seems to levitate in the air above the yawning excavation that exposes the old foundation. Walk off that final step now and you’d fall 35 feet to the base of Tuesday’s concrete pour. Then you’d look up from the ground at the new concrete foundation base, which is six feet tall.

That deep concrete is dense. The strength of the concrete in a normal driveway is 2,500 to 3,000 pounds per square inch. Typical concrete walls or columns are 3,000 to 5,000 psi. The concrete in Tuesday’s pouring of the foundation is 8,000 psi.

In a couple of weeks, after all that dense, new concrete cures or dries, workers will begin to install the first of the 98 base isolators that will hold the temple separate from the earth, Kirby said.

“The seismic work is what we call our critical path. We can’t do other things until it’s finished,” he said.

“So, yes, I would say we’re 50%, because we’ve done all the preparation. Now we’re building up out of the ground. Today’s a milestone in that process, where we’re casting the west footing. The west footing goes all the way around the three west spire towers of the Salt Lake Temple, inside and outside.”

By inside and outside, Kirby said, he referred to the fact that the concrete pour filled huge molds extending many feet outside the temple wall as well as underneath the temple wall. Where one base isolator will be set on the new concrete just outside a wall, a sister base isolator paired with it will be placed next to it under the temple wall.

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“It’s the largest pour and it’s a very, very difficult pour because the footings are full of steel reinforcement,” he said. “It’s a it’s an intricate design for a footing. I’ve never seen reinforcement like this, in my experience.”

Concrete is poured at the Salt Lake Utah Temple of The Church of Jesus Christ of Latter-day Saints.
Concrete is poured at the Salt Lake Utah Temple of The Church of Jesus Christ of Latter-day Saints on Tuesday, April 11, 2023 in Salt Lake City. | Jeffrey D. Allred, Deseret News

The goal is to transfer the 187-million-pound temple onto the new footings instead of the historic footing.

“That process will be complete at the end of the year, when we transfer the load onto these new footings we poured today,” Kirby said.

Building upward already has begun in one area. Previous large concrete pours set the foundation on the temple’s north side, where walls for the first two lower levels have been built, Kirby said.

The trucks rolled up to dump concrete into two pumping stations on North Temple street and onto the construction site between the temple and the Salt Lake Tabernacle. They were scheduled to pour 1,600 cubic yards of concrete into the footings for the west tower.

Trucks wait in line to pour concrete at the Salt Lake Utah Temple.
Trucks wait in line to pour concrete at the Salt Lake Utah Temple of The Church of Jesus Christ of Latter-day Saints in Salt Lake City on Tuesday, April 11, 2023, during an all-night pour. | Jeffrey D. Allred, Deseret News

The tower has been stripped of its ornate spires and decorative finials, or stone features, to protect them during the renovation. The spires and finials are in storage in a nearby warehouse. Workers removed the gold-plated Angel Moroni statue and placed it in storage in 2020 after an earthquake knocked the trumpet out of its hands.

President Nelson announced the project in 2019 and said the church would hold an open house for the temple once the renovation was complete. It will mark the first time the general public will have been able to enter the temple since its original dedication in 1893.

The temple closed in the final days of 2019 and work began at the start of 2020. The renovation project initially was expected to take four years, with the temple reopening in 2024. Unexpected challenges presented by the excavation of the temple’s foundations have led to two announcements of extensions. The temple is now expected to be completed in 2026.

Concrete is poured at the Salt Lake Utah Temple of The Church of Jesus Christ of Latter-day Saints.
Concrete is poured at the Salt Lake Utah Temple of The Church of Jesus Christ of Latter-day Saints in Salt Lake City on Tuesday, April 11, 2023, during an all-night pour. | Jeffrey D. Allred, Deseret News
Concrete is poured at the Salt Lake Utah Temple of The Church of Jesus Christ of Latter-day Saints in Salt Lake City.
Concrete is poured at the Salt Lake Utah Temple of The Church of Jesus Christ of Latter-day Saints in Salt Lake City on Tuesday, April 11, 2023, during an all-night pour. | Jeffrey D. Allred, Deseret News
The moon shines on Temple Square as concrete is poured at the Salt Lake Utah Temple.
The moon shines on Temple Square as concrete is poured at the Salt Lake Utah Temple of The Church of Jesus Christ of Latter-day Saints in Salt Lake City on Tuesday, April 11, 2023, during an all-night pour. | Jeffrey D. Allred, Deseret News