Category: Mixed Use
Summary: When Watts Group began their work on The Madison in Coralville, IA, they started the project as they always do, by analyzing the cost of precast versus traditional foundation walls, and then looked at their timeline. Due to a couple challenges with the project, and the benefits offered by precast, it quickly became apparent that utilizing precast concrete foundation walls, as well as other precast components, was the way to go.
Precast Components:
15,493 square feet of 8” Hollowcore - 1st Floor
11,582 square feet of 8” Hollowcore - 2nd Floor
5,372 square feet of 12” Hollowcore - 2nd Floor
43 Beams
22 Columns
139 Wall Panels (30,320 square feet)
181 square feet of 8” Wet Cast Slab
Case Study: In 2016, Watts Group began work on a Mixed Use building which would include two floors of condos for rent, one floor of high-end penthouses for purchase, commercial space on the main floor, and underground parking. By analyzing the cost of precast versus traditional foundation walls, and taking their timeline into consideration, it was determined that utilizing precast foundation walls and other precast elements was the way to go on this project.
”We knew we wanted to be out of the ground pretty quick and precast always allows that,” said Adam Hahn, Director of Construction Services for Watts Group, 425 E. Oakdale Blvd., Suite 101, Coralville, Iowa. “As soon as the foundation is done, we’re basically ready for walls from a precaster and in two weeks we can be out of the ground and ready for other trades. Had we used traditional cast-in-place, the timeline would have been four times as long.”
Watts Group typically reaches out to Mid-States Concrete early in their process for preconstruction assistance. Troy Yaun, Mid-States Concrete’s Preconstruction Representative in Iowa, is a big proponent of getting involved in projects in the very early stages. He said working side-by-side with the customer, as well as the architect and engineer of record ensures that everyone has a clear understanding of the precast components of the project, and all the benefits that come with it. Some of these benefits include durability, speed of installation in the field, versatility, and efficiency. It also gives the team a chance to identify potential issues early on, and solve them before they actually become a problem.
”We knew there was a desire from the company who bought the first level commercial to make sure there was no issue with sound between the retail space and the apartments above, so that was the big reason we ended up taking precast all the way up to the second floor,” Hahn said. “The other reason is, with underground parking, we knew with this style of building and the spans we were looking at, the best option was precast.”
The Mid-States team knew precast foundation walls were a good fit for this project for several reasons, including the speed of installation and so the contractor would only have to manage one trade instead of multiple trades and materials. In addition, the site conditions lent themselves well to precast foundation walls. Precast also accommodated the heights needed for the walls, which were 20 feet from floor-to-floor with large openings.
In this instance, the foundation walls were the bearing walls for the hollowcore floor system over the garage, which was also constructed with precast beams, columns, and hollowcore.
”It just made more sense to integrate all that precast rather than have multiple trades trying to coordinate and make sure all the pieces go together,” Hahn said. “It is much easier to have one party responsible for it than separate parties.”
On this project, now known as The Madison, a couple of potential issues were identified early on. At the beginning of planning, Watts Group knew there was potential for a high water table, so completing foundation work quickly was very important for this project. As construction began, the team did have to fight with the water table a bit, so Hahn firmly believes using precast foundation walls saved both time and money.
”I have to believe I would have spent more money pumping water and potentially pushing us into winter (and needing) heating with other systems,” Hahn said.
Additionally, the project had an arched front wall that carried up through the entire building.
”Again, it would have taken more time on site for a traditional foundation crew to work through and figure it out, where we already had it figured out with the embeds and everything already located in our footings,” Hahn said.
Other challenges included two cantilevered beams coming together at the corner of the building that was carrying load from above and dropped corridor area that was supported by the first floor. Getting the crane down the ramp to the lower level was also a challenge.
According to Mid-States Project Manager Toby Bennett, the limits of the site create conditions that only allowed for specific placement of the main crane and trucks to be unloaded. This required an additional crane to be brought in to “tail” the precast wall panels as they were lifted from the trucks. While an approved practice, this was a non-typical install.
Fortunately, with all of the upfront work between Mid-States, Watts Group, OPN Architects, and Raker Rhodes Engineering, the team was well-prepared for the challenges.
Hahn was also pleased with the construction planning and installation work provided by Mid-States. The Mid-States team provided a clear pick plan, material shipping schedule, and staging plan, so Watts Group knew exactly where the rock drive needed to go to accommodate all the trucks coming and going.
”There was a lot to install and we didn’t have any hiccups from embed locations in the footings to any embeds that were in castings,” Hahn said. “Everything went together pretty seamlessly, without any issue that made it back to me.”
This wasn’t the first project Hahn utilized precast foundation walls for, and it won’t be his last. Typically, precast foundation walls can be a good fit for mixed use, multi-family buildings with underground parking.
”In roughly a month timeframe, we were able to go from 20 feet below grade to 50 feet above grade with a structure and ready for the building to be framed on top of the podium,” Hahn said. “Whenever we use precast foundation walls, hollowcore, beams, and columns, everybody is always so impressed at how quickly a building comes out of the ground. As somebody that owns a lot of the buildings that we build, we have the time to preplan a project and can get precast involved early. The coordination of our projects has always been excellent.”
Do you want to learn more about how Mid-States Concrete’s foundation walls could work with your project? Our preconstruction team is happy to assist.
Wisconsin: Jeremy Olivotti
Iowa: Troy Yaun
Wisconsin/Iowa/Illinois: Colin Jones