After a decade of trying to determine what’s causing the failure of a high-tech coating covering the top portion of its historic downtown water tower, Riverside officials may have finally gotten their answer.
It’s a result of the 2004 restoration of the tower, which cost the village $1.37 million.
That, at least, is the short version of the problem as explained by Koo LLC, a Chicago-based architectural firm hired earlier this year to analyze why the mineral stain applied to the brick exterior of the tower’s upper portion has failed.
According to an Aug. 9 memo to Village Manager Jessica Frances that included Koo LLC’s report on tower conditions, Public Works Director Edward Bailey stated that the repairs recommended by Koo LLC would amount to between $750,000 and $1.2 million to complete.
Koo LLC’s report was delivered to village officials at the end of June and unveiled as part of a preliminary village board discussion of Riverside’s 2017 operating budget on Aug. 18. The firm identified structural repairs made as part of the restoration as being directly related to the failing mineral coating.
Workers added large areas of stainless-steel flashing to original structural elements inside the tower. But the addition of the flashing resulted in a thinner exterior brick veneer in those areas. The change resulted in hairline cracking of the brick, which introduced more water into the tower wall, “exacerbating the failures in the masonry and coatings.”
The flashing also traps moisture behind and within the brick, the report states, instead of allowing it to dry.
“Excess prolonged moisture in the brick and mortar can push out salts and other minerals that can contribute to coating failure,” the report states.
In addition, the firm said that a failure to seal off heat generated by the finished ground-floor spaces inside the tower from the unfinished tower space above them also contributed to the problem.
During cooler months, warm air from the ground floor is drawn up into the tower, creating condensation on the metal trusses and steel flashing “and ends up in the masonry wall.”
The firm’s recommended fix includes repairing and replacing masonry in the tower, recoating the portion of the tower where the coating has failed and sealing off the ground-floor spaces to prevent warm air from moving into the tower during cooler months.
Part of the repair would involve re-engineering the masonry to eliminate the thin veneer and re-engineer the steel flashing to prevent condensation and water retention.
Koo LLC also examined the metal roof of the water tower, where paint has peeled extensively. The firm’s report suggests that the work to prepare and paint the roof when it was restored in 2004 was simply poorly executed and didn’t use an appropriate paint.
The report states, “It does not appear that the surfaces were prepared or primed prior to the coating.”
Among the firm’s recommendations for the roof is to remove all that’s left of the 2004 paint, sand all of the surfaces and then pressure wash the roof before coating it with a high-performance paint made specifically for structures such as water towers.
In 2004, a product made by the Benjamin Moore paint company was used, according to Bailey.
In a phone interview, Village President Ben Sells said he likely will suggest engaging the Riverside Preservation Commission to help formulate a plan of action to address the water tower.
Meanwhile, Bailey indicated that $75,000 set aside in the 2016 budget for spot painting of the water tower bricks could be used to address the roof. He said that work could be completed this year, though it has not been scheduled yet.
Sells indicated it might make sense to roll a discussion about repairs to the water tower into a larger discussion of public building facilities, one that might also include the police station, main fire station and the former Youth Center building.
“We need a comprehensive look at that entire area over there,” Sells said. “We can’t continue to let it dilapidate. This water tower [repair discussion] can be part of that. I’d suggest we give it as a formal project to [the] Preservation [Commission].”