After months of the two structures standing surrounded by scaffolding and sheeting, work will begin at last on Monday to remove and replace exterior tiles on Gallagher Hall and the UC Davis Conference Center.
The much-ballyhooed, LEED platinum-certified buildings — which opened in October 2009 and February 2010, respectively — were wrapped up last fall after experts found many of the Italian ceramic tiles above the first story weren’t properly adhered.
Closer examination showed that the cement-rich mortar between the tiles and buildings had been applied too thickly. Tiles became loose when the material shrank about 3/4 of an inch, said Alex Achimore, senior project manager with UCD Design and Construction Management.
The repairs will take about 2 1/2 months, he said. Work will be planned so that as many areas as possible around Gallagher, home to the Graduate School of Management, will be finished before the school’s June 15 graduation.
Perhaps two-thirds of the tiles will need to be taken off and the mortar behind them removed, then adhered with a mortar that has a higher bonding strength and that shrinks less, Achimore said. Most of the tiles should be able to be reused.
Sundt Construction of Sacramento, the general contractor in charge of the buildings’ construction, will handle the repairs. Senior Vice President Cody Pearson said that depending on the work needed, it likely will cost his company $250,000 to $400,000.
“Both UC Davis and Sundt have gone through their experts and come to a collaborative agreement about how to solve the problem,” said Pearson, who said the tile work was performed by a subcontractor. “We’re moving forward to get it corrected.”
The first sign that something was amiss came about two years ago, when part of a tile fell from Gallagher Hall. Then, in April 2012, a whole tile crashed down.
Tap testing with a mallet was done to try to locate hollow spaces behind tiles. Later, tiles were removed and laboratory tests performed to try to determine the problem.
“The realization started creeping in that it was more than a few tiles,” Achimore said. ”The higher you go, the easier it is to pull the tiles off. It’s not easy enough that most were going to fall off, but enough if you use a tool you can easily break them free.”
UCD opted to surround the buildings with scaffolding early in the fall, for safety’s sake. Meanwhile, the campus and Sundt listened and discussed as experts went back and forth “arguing over minutia” on cause and solution, he said.
The university later hired a second consultant for one more look. It identified other potential “micro stresses” that could affect the building’s exterior, but UCD ultimately decided that the new mortar should be sufficient to withstand them, Achimore said.
The scaffolding and sheeting called to mind the massive 2011 repair job on the Mondavi Center for the Performing Arts, just across the grass quad, but Achimore said the problem there was not the tiles or the mortar, but a waterproofing membrane that was applied too thin and left the building vulnerable to rainwater.
Unlike Mondavi, Gallagher Hall “hasn’t leaked a drop,” Achimore said.
For the Mondavi Center, 50,000 sandstone tiles, more fragile than those on the new buildings, needed to be broken off, new sheathing installed and a new protective membrane applied, then replacement tiles shipped in from India put on.
Another difference: Much legal wrangling, culminating in a $7.1 million mediated settlement deal among UCD and its general contractor, McCarthy Building Companies of St. Louis, as well as Boora Architects of Portland, Ore., 10 subcontractors, three insurance companies and the company that produced the original waterproofing materials.
Gallagher Hall, with a glass front that echoes the Mondavi Center, and the conference center to which it is connected by a sky bridge were hailed for their sustainable design features when the $33.5 million, 83,000-square-foot complex opened.
Gallagher boasts a heating and cooling system believed to be the first of its kind in the United States, with pipes placed under the ground, where temperatures remain about 60 degrees. In summer, water is chilled there, then circulated in the radiant slab and floor systems to cool the building. In the winter, an energy-efficient boiler and pump send warm water through the buried loop.
An energy consultant has found that the building exceeds state energy-efficiency standards by 33.6 percent.
Achimore called its performance “basically excellent.”
“The first year was a little rocky, in terms of tuning it up, but I believe it’ll get there,” he said. “We’re definitely proud of it in every respect. (The problem with the tiles) is an unfortunate workmanship thing that’s hard to control.”
Sundt has served as the general contractor on a number of builds on campus, among them the School of Veterinary Medicine’s new research building and the UCD Health System’s Education Building and Blaisdell Medical Library on the Sacramento campus.
The firm is also heading up the construction of the $71 million, seven-building Tercero 3 student housing project, due open in 2014.
— Reach Cory Golden at firstname.lastname@example.org or 530-747-8046. Follow him on Twitter at @cory_golden