Saggy Kingsbury condo floor calls for extreme solution
UPPER KINGSBURY – What do you do when your floor sags and your building begins to slide downhill?
“Nobody thinks about it unless it happens to them,” said Norm Denny of Pinnacle Construction Consultants in Minden.
This spring, Denny was asked to fix a three-story, 40- by 80-foot, 12-unit condominium building at Daggett Summit, when the floor sank up to 5 inches in places and the building slipped down the mountain a couple of inches.
Denny, who has done work in the past on other condominiums at the top of Kingsbury Grade, called a structure and soils engineering company, obtained a construction crew and hired a company that installs foundation support systems.
Their main objective – to lift the sagging floor and secure the building.
“In May, one of the units had sold,” said Denny. “One of the owners pulled the carpets and pads out and noticed there was a 5- or 6-inch sag in the floor in the center of the kitchen and living room area. This was on the third floor.
“I traced it down to the bottom floor.”
Denny found out that a 2-inch water main had burst in July 2003 and was not discovered for eight hours.
“It was a tremendous amount of water,” said Denny. “In the under-floor area the water trench was 12 inches deep.”
When one of the supports, or piers, began to sink, it caused a chain reaction all the way up the building, he said. Floor levels had lowered between 2 1/2 to 5 inches in areas and the northwest corner of the building had gone down 2 inches.
Denny kept the homeowners informed of each step throughout the almost five-month-long process that followed.
First, Ferrari, Shields and Associates of Reno, a structural engineering firm, measured water levels in each unit. Then, Pezzonella & Associates in Reno, a soils engineering company, determined the type of ground beneath the building – mainly rock and decomposed granite. Next, Miles Bros. Construction of Carson City made all the repairs needed before the building could be raised.
On Thursday, after workers from Utah-based Atlas Piers cleared snow from the aftermath of Wednesday’s storm, they began installing metal piers, or supports, along the base of the back and underneath the building.
The winds are biting up there, but soon a somewhat safe dirt path led down to where they worked. Using 10 hydraulic jacks, at about 3 p.m. the side of the building was raised about 2 inches. Helical coils, resembling giant screws, were drilled into the mountainside.
“Like a corkscrew, they go at a 15-degree angle into the mountain until they won’t go any farther,” said Denny.
“There are so many rocks. We’re lucky to get in what we did,” said Larry Mertin, president of Atlas Piers.
Mertin said the building did not need to be evacuated, but he thought most of the residents had decided not to stay home during the process.
This was just the first phase of the $250,000 project, according to Denny, who said Phase 2 will be reconstruction of the decks that came loose, and Phase 3 will include landscaping and water drainage, under Tahoe Regional Planning Agency’s best management practices.