Lighten Up

Originally posted online at Constructor Magazine, Web Exclusive


Projects built with geofoam include road beds, bridge approaches, levees and other jobs.

Projects built with geofoam include road beds, bridge approaches, levees and other jobs.

Contractors have successfully used expanded polystyrene (EPS) geofoam to simplify site preparation since the 1960s. Projects built with the material include road beds, bridge approaches, levees and other civil jobs. Now, geofoam is increasingly solving a host of construction challenges in commercial buildings and large residential applications.

Geofoam is an ultra-lightweight, engineered, closed-cell rigid foam. The material is about 100 times lighter than soil and weighs substantially less than other lightweight fills.

Even though it is very light, geofoam is high strength, with compressive resistance values of 317 to 2,678 lbs/ft2 at a 1 percent strain. Geofoam is suitable for a range of heavy loading conditions, including sub-base for pavements and railroads bearing jet aircraft and locomotives.

EPS geofoam changes the traditional soil compaction phasing method in which contractors mechanically compact soil to a percentage of dry density and pay for multiple samples and laboratory tests. Unlike other lightweight fills such as shredded tires or wood chips, EPS geofoam is homogenous, which provides uniform load transfer and eliminates differential settlement.

The combination of lightweight and high strength makes geofoam the ideal material for many building applications, including:
• Creating level building pads on steep-sloped lots
• Stabilizing steep slopes
• Remediating soft soils
• Forming swimming pools and pool decks
• Landscaping
• Creating theater/stadium seating

Creating level building pads on steep-sloped lots
Given its lightweight, contractors can use geofoam to simplify construction of retaining walls needed to level steep-sloped lots. Geofoam drastically reduces or can eliminate the lateral load on retaining walls, so walls do not need to be as robust. Material and labor costs are much lower due to reducing forming, structural steel and concrete volume, and lessening or eliminating the need for geogrids or mechanical tiebacks.

Eckhart Construction Services, a Carolinas AGC member, used geofoam to create a level building site for a McDonald’s restaurant. There, a retaining wall was needed that could accommodate the change in grade, as well as reduce the load over extremely soft soils. Typical soil fill would have caused unacceptable settlement of the retaining wall. The use of EPS geofoam allowed for incorporation of a traditional keystone retaining wall while eliminating the need to use the typical geogrid material to reinforce the retaining wall.

Stabilizing steep slopes
Geofoam’s lightweight makes it an excellent option for stabilizing steep slopes, without the need to change the final slope geometry. Since the material is much lighter than other fills, it greatly reduces the weight of a slope’s driving block and lowers the risk of costly and dangerous landslides. An additional advantage of using lightweight geofoam blocks on slopes is that crews can move and place them by hand. This eliminates the need for heavy earth moving and compaction equipment on steep and uneven terrain.

Remediating soft soils
Ground with soft soils or soft clay makes building construction notoriously difficult. To eliminate or greatly reduce the need for time-consuming and costly surcharging of soft soils, EPS geofoam provides high load support at a low weight for projects of all sizes.

An example is the renovation of an existing office building into a city hall in the Pacific Northwest. Building codes required installation of new handicap ramps as part of the upgrade. The challenge was the project site is situated on extremely soft glacial till at the south end of a lake. As such, the ramps needed a very lightweight void fill to avoid post-construction settlement. After evaluating various lightweight fill options, the project team chose EPS geofoam. Crews installed 5,000 cubic yards of geofoam, which played a role in helping the project be completed two months ahead of schedule and nearly $600,000 under budget.

Forming swimming pools and pool decks
Contractors use geofoam to simplify construction of swimming pools in residential, commercial and institutional uses, including hotels, schools and community centers. Project teams can order the blocks pre-cut to precise dimensions or can easily cut them to size and shape on site. This simplifies the concrete forming process, and greatly reduces weight for construction of rooftop pools or on sites with poor load-bearing soils. Once crews form the pool basin and decks with geofoam, they can apply shotcrete directly to the foam.

Because crews can readily form geofoam into a host of shapes, the material provides a simple way to create landscape topography and berms. This is particularly beneficial when loads must be minimized on underlying structures and utilities. Examples include rooftop gardens and landscaped spaces with shallow buried utilities that cannot bear the weight of soil fills.

Creating theater/stadium seating
Geofoam provides contractors a fast and simple way to change slopes within buildings – either creating tiered seating as in auditoriums, movie theaters, churches or gymnasiums, or leveling out such a sloped space for other uses.

For stadium style seating, crews hand place row upon row of geofoam blocks to achieve the necessary profile. They can then either place concrete over the geofoam as shotcrete or as pre-cast panels. Using geofoam greatly simplifies the forming process and eliminates the need for complex tiered compacting of soil to form the stepped profile of stadium seating.

Crews can also use geofoam to quickly level an existing sloped elevation in a building. For example, a university wanted to convert a sloped floor lecture auditorium into a surgical suite at a hospital. The project engineers specified EPS geofoam as a structural void fill to reverse the slope. The EPS supplier cut the blocks to minimize field fabrication on the job site. Because the enclosed auditorium did not have space to accommodate heavy equipment, and as noise from mechanical compaction of soil would have disrupted hospital patients and staff, geofoam was an ideal alternative. The lightweight structural fill provides a strong, stable sub-base for the new, level concrete floor slab.


Even though it is very lightweight, geofoam is high-strength and suitable for a range of heavy loading conditions.

Even though it is very lightweight, geofoam is high-strength and suitable for a range of heavy loading conditions.

Although geofoam can be manufactured in many sizes and shapes, standard blocks are typically 4 feet wide by 8 feet long, and of varying thickness. If contractors do not order geofoam precut to specified dimensions, they can easily trim geofoam to size using a hot wire cutter (which some manufacturers will supply) or with a handsaw or a chainsaw onsite.

When placing geofoam, the blocks are staggered so their joints are not located in the same vertical plane. At times, the blocks are interconnected with either barbed plates or polyurethane adhesive, in accordance with engineering specifications.

Due to geofoam’s lightweight, crews can maneuver and place the blocks by hand or with small mechanical equipment. A typical installation is to place geofoam blocks on a level course over sand, pea gravel or any locally available permeable leveling course material.

Following are points to keep in mind when working with geofoam:

• Geofoam is subject to damage when exposed to certain hydrocarbon chemicals or solvents. If needed, crews can protect the material with hydrocarbon-resistant geo-membranes or concrete slabs.

• Manufacturers treat geofoam with a fire retardant to avoid the rapid spread of fire. However, the material is combustible at high temperatures, so it is important to be cautious when conducting hot work, such as welding, around geofoam.

• Exposing geofoam to sunlight for extended periods can cause superficial discoloration, which does not impact the product’s integrity and can be removed with a broom or very light pressure-washing, if desired.

• Because geofoam is lightweight, it is important to take care when stockpiling the material on job sites where windy conditions exist. Contractors should weigh or tie-down stockpiles, as necessary.

Soil fills will continue to factor prominently in construction given their ubiquity and familiarity, but for challenging projects, geosynthetics like geofoam are increasingly popular. Geofoam offers contractors a simple-to-use, engineered alternative to traditional earthen fills. The material solves a host of site preparation challenges in commercial and large residential building projects.

Maggie Daley Park to Turn Garage into Rolling Hills- ABC Chicago News

More news coverage on the use of InsulFoam Geofoam in Chicago’s newest and biggest downtown attractions, Maggie Daley Park. When complete, the new park will have a distinctive presence with signature elements like rock-climbing sculptures, an ice-skating ribbon, and play garden.  Read more in the latest and on-going news coverage on details and view the project’s job site camera:

– Geofoam Helps Mold the Construction of Chicago’s New Downtown Maggie Daley Park.

  Foam Blocks Form Hilly Landscape at Maggie Daley Park Site, Chicago Sun-Times

Originally aired and published on  ABC 7 Chicago News, by Paul Meincke

chicago abc_maggie daleyBuilding a park on top of a parking garage is an engineering question whose answer rests with the new Maggie Daley Park on Chicago’s lakefront.

In the shadow of towers made of concrete and steel, there are building blocks of a different sort. Thousands of them are being layered together to give shape to what will be Maggie Daley Park.

“We’re going to transform what was a flat, sort of uninviting area into a gem for Chicago that compliments Millenium Park,” said Chicago Park District CEO Michael Kelly.

That transformation has a lot to do with topography. When this 20-acre park is done, its northeast corner will sit 30 feet higher than the southwest. That’s a lot of dirt. And dirt weighs a lot. And a lot of weight would not be welcome atop the two story parking garage that sits directly underneath. So, what do you use? Geofoam.

“Geofoam is essentially Styrofoam. It’s lightweight fill,” Kelly said

It’s 100 times lighter than soil. Geofoam isn’t a new concept. It was used here before, but there’s a lot more of it now, 75,000 cubic yards of it will be sculpted and tacked down to create a rolling terrain.

On top of the geofoam goes the dirt which will be deep enough in spots to accommodate the roots of one-thousand new trees. If you’d never seen the geofoam going in, you’d never know it was there.

“That’s essentially the best compliment we could get once this park is open and that is that people don’t realize that it’s a park constructed on top of a garage,” said project engineer Nichole Sheehan. “It’s a park that people are going to love and hopefully come to all the time.”

The park district has been recording its birth with time lapse camera, from barren garage roof to the building of baby hills, and when the park’s soft opening comes next fall, this is the vision. Three of the 20 acres devoted to a children’s playground. Just up the path, a 25 foot climbing wall, and when the cold months come, a feed of built in refrigerant will convert that path into a 400 meter ice skating ribbon – attracting old Hans Brinkers or perhaps young Blackhawks.

From debris dating back to the great Chicago fire to geofoam, this piece of Chicago has undergone remarkable change over the years.

In the late 40’s and early 50’s, there were lots of railroad, lots of parking that over the years goes went away or went underground.

“Somewhere way down there, there’s fill,” Kelly said. “There’s probably some old railroad scrap. Now we’re standing on geofoam and we’re building a green park. We’re building a 20 acre green roof is essentially what we’re doing with a thousand trees.”

The first of the trees come soon. The grand opening of Maggie Daley Park comes next Spring. Its birthing thus far carries four words welcomed in urban re-design.

Maggie Daley Park carries a roughly $55 million price tag. Most of that comes from parking garage lease money and private contributions along with five million in park district capital funds.


Foam blocks form hilly landscape at Maggie Daley Park Site, Chicago Sun-Times

Great story in the Chicago Sun-Times about the use of InsulFoam Geofoam in Chicago’s newest and biggest downtown attractions, Maggie Daley Park.  This is a very large geofoam project, the new park will have a distinctive presence with signature elements like rock-climbing sculptures, an ice-skating ribbon, and play garden.  Read more details and view the project’s job site camera:  Geofoam Helps Mold the Construction of Chicago’s New Downtown Maggie Daley Park.

Originally published on Chicago Sun-Times,, by Tina SFondeles


Maggie Daley Park is being formed using GeoFoam, a plastic foam substance that has been used once the ’80’s to create landscape and hills on others flat land.  – Brian Jackson  |  Sun-Times

Chicago’s shoveling days should be over, but the future Maggie Daley Park kind of looks like a winter wonderland, full of white building blocks.

Those giant blocks of Geofoam will transform flat land into a hilly landscape at the park site, which spans 20 acres and is bordered on the west by Columbus, the north by Randolph, the south by Monroe and the east by Lake Shore Drive.

Landscape architects say the lightweight, cost-effective, environmentally safe and recyclable fill material is key to creativity. The expanded polystyrene is being used around the world and locally to contour flat Midwestern land.

At Maggie Daley Park, crews are using old Geofoam — already part of Daley Bicentennial Plaza — and a lot of new blocks to shape the park. From various vantage points around the park, onlookers can watch as the foam is delivered every day — six truckloads — and crews have already filled the northeast and northwest corners of the park, and are moving south.

The foam installation will be done by early summer. By September, dirt will be placed over the foam. It’s even being used for the park’s ice skating ribbon.

“For the ice ribbon, you’ve got up and down. It’s not just flat,” said Lowell Zarzueta, of Walsh Construction, who is overseeing part of the second phase of the project. “For you to go up high, you almost have to skate super fast, just to get over that little hump.”

He said the foam is being used to create a hill that will be even with Randolph Street, making it easy for people to come into the park. There are also peaks at the northeast corner, where a picnic area is being built.

“With Maggie Daley Park, you’re going to have hills. The park will offer these beautiful vistas of Lake Michigan, which it never had there,” said Bob O’Neill, president of the Grant Park Conservancy. “In order to do that, to get these hills, and these rolling meadows over a whole flat area in Chicago, to get any topography, especially on top of a structure, you need Geofoam.”

Crews on Friday said deliveries of Geofoam are about half done. The mass quantity of snow Chicago received this year did slow work a bit, but crews said phase two of the park — earthwork, utilities, paving, architectural and program elements, soil placement and planting — is on schedule for completion in October.

Here’s how crews are layering the park: First it was excavated, the dirt placed in nearby Peanut Park to be reused. Tar was put over the garage, then a layer of black tarp. It’s then tested to make sure it’s waterproofed to prevent leaks to the garage below. Four inches of stone are placed on top, and then the foam is placed with yet another black tarp over it. Dirt will go over the foam.

Come next spring, the ground will become green again, as landscaping and planting will be in full swing.

This isn’t the first time the product has been used in Chicago. It was also used for the Daley Plaza renovation — where the trees are now planted, and for the Soldier Field remodeling, where Geofoam was placed as fill over the garage, creating a hilly and grassy landscape near Soldier Field and the Field Museum.

Peter Schaudt, the landscape architect behind both renovations, said Geofoam played a major role in the projects.

“I think it allows you the freedom to be creative,” said Schaudt, of Hoerr Schaudt Landscape Architects. “It allows you to really model the land in an artificial way, and the great thing is when you put the soil and lawn and trees on top of it, it’s an illusion.”

The product also is very strong, he said. “It never dematerializes. It stays the same size. At Soldier Field, it was used to support 18,000 pounds.

“It’s much more substantial than just putting a thin veneer over a roof, and it allows you to create a lot of great and dramatic changes,” Schaudt said.

A soft opening for the $55 million park, named for the late wife of former Mayor Richard M. Daley, is scheduled for fall, and the park will be officially completed by spring 2015. A park district website, features two webcams to view the construction.

Email:  |  Twitter: @TinaSfon

Applications, Design & Construction Considerations for EPS Geofoam

Originally posted on CE News online in Progressive Engineering

Geofoam: A lightweight fill alternative

Pacific Bridge

To widen the Pacific Street Bridge over I-680 in Omaha, Neb., Hawkins Construction excavated the soil between the existing abutment wall using EPS geofoam as lightweight backfill for the bridge approach.

Geofoam is a rigid, engineered, lightweight fill material typically made of expanded polystyrene (EPS). For fills, a key advantage of EPS geofoam is its low weight — approximately 1 to 2 percent the weight of soil. Typical densities for EPS fill are between 0.7 and 2.85 pounds per cubic foot, therefore maintaining a predictable compressive strength that is suitable for many structural applications (see “Geofoam physical properties”).

Today, geofoam is fully recognized and accepted as a lightweight fill alternative and has seen increased use in commercial and residential applications. Since the first installation of geofoam in 1965 (see “A short history of geofoam”), numerous projects around the world that have relied on the material to solve construction problems.

Given EPS geofoam’s low weight, strength, and ease of use, more project teams are using it to solve regular construction challenges in five basic applications.  Read the full article featured on CE NEWS as our Geofoam Specialist, Nico, discusses:

  • The five basic applications and specific project examples:  1.)  Lateral load reductions on structures  2.)  Soft soil remediation  3.)  Slope stabilization  4.)  Lateral and dead load reductions over buried utilities  5.)  Lightweight structural void fill.
  • Geofoam physical properties
  • Short history of geofoam
  • Construction considerations
  • Cost saving advantages

Geofoam Saves Time, Money During Three Projects

Originally posted on Better Roads Magazine

I-80 / I-65 Interchange, Gary, Indiana

I-80 / I-65 Interchange, Gary, Indiana

The Federal Highway Administration (FHWA) has promoted the use of expanded polystyrene (EPS) geofoam as a lightweight embankment soil alternative for a number of years.  In a 2006 report, the agency’s Technical Service Team described the material as a “field-tested, budget-friendly winner.”  Why?  FHWA engineers list the following benefits:

  • Accelerated construction
  • Payroll, transportation and equipment cost savings
  • Reduced labor time for construction
  • Exerts little or no lateral load on retaining structures
  • Easily constructed in limited right-of-way situations
  • Allows application in adverse weather conditions.


The material is approximately 100 times lighter than soil, which save time.  Additionally, a single truck can carry approximately 120 cubic yards of goefoam versus 12 dump truck loads needed for an equivalent volume of earthen fill.  This reduces hauling costs, both in fuel and labor.  Geofoam is easy to install by hand, so it reduces expenses for heavy equipment.

Following is a discussion of tangible benefits derived from geofoam usage in real-world applications such as:

I-80 / I-65 interchange, Gary, Indiana:  FHWA recommended a net-zero load methodology for the roadbed to prevent post-construction settlement.

To reduce the amount of excavation of the high-organic content soils, the contractor, Walsh Construction, used EPS geofoam blocks.  A six-member crew installed 700 cubic yards of geofoam in one week working four- to five-hour days. The geofoam was delivered to the job site on 32 flatbed truckloads, whereas traditional fills would have required more than 400 dump trucks in the highly congested project area leading into and out of metro Chicago.

Highway Interchange, Valsayn, Trinidad:  The project team for an interchange between Trinidad’s Churchill-Roosevelt Highway (CRH) and Uriah Butler Highway (UBH), the island nation’s primary highways, used an EPS geofoam sub-base to solve an engineering challenge and save time in the process.

Highway geometry required placing new lanes adjacent to both sides of an existing fly-over ramp’s support pier. The grade for the lanes required placement of about 10 feet of embankment fill on top of the pier’s pile cap. Engineers determined that traditional fills would have caused unacceptable settlement of the compressive layers located below the fill.

To build the embankment while keeping loads down on the pile cap, Vinci Construction Grands Projets specified EPS geofoam as a lightweight fill, which provided an alternative to building a concrete slab founded on piles to support the load from the road and transfer it away from the pier pile cap. No heavy equipment was needed for the fill placement, as crews were able to install the geofoam blocks by hand.

The geofoam resulted in lower and smoother post-construction differential settlements of the roadway in both the transversal and longitudinal directions. It also eliminated the need for additional geotechnical investigation for potential additional piles. The ability to place the EPS geofoam during the rainy season was crucial to keeping the project on schedule. Crews placed 2,100 cubic yards of EPS geofoam in only 3.5 days.

Lake Cataouatche Pump Station Bridge, New Orleans, Louisiana:  The U.S. Army Corps of Engineers used EPS geofoam when it needed to build a service bridge over above-ground outlet pipes at the Lake Cataouatche pump station near New Orleans.

The bridge abutments are over extremely soft soil (compressible peat). A traditional soil embankment would have added substantial load to the underlying soils. To minimize loads on the soft soils, the project team used EPS geofoam under the bridge abutments.

Final thoughts

In addition to being lightweight, EPS geofoam has predictable elastic behavior and will not decompose. Further, unlike other lightweight fills such as shredded tires or wood chips, EPS geofoam blocks are homogenous, which provides uniform load transfer and eliminates differential settlement. All of these factors combine to make the material an ideal choice in many road sub-base applications at the federal, state and local levels.

Geofoam Helps Mold the Construction of Chicago’s New Downtown Maggie Daley Park


Maggie Daley Job Site Cam, Dec 7th

Maggie Daley Job Site Cam, Dec 7th

With construction well underway the former Daley Bicentennial Plaza (next to Millennium Park) is on its way to being one of the “greenest” parks in America. The park is atop the large East Monroe Street Parking Garage, which has been restructured extensively including a new membrade above the garage which will also serve as the foundation that the park will sit on top of.

The new park, offers sweeping views of Lake Michigan, and combined with Millenium park “Peanut Park” will offer 45-50 acres of green roof over a downtown city parking garage.
So what does Insulfoam’s EPS Geofoam have to do with it? With about 60% of earthworks completes, crews have removed 82,000 cubic yards of existing fill (that existed beneath the soil for decades). Some of this is in fact lightweight fill material like Geofoam, and is still in excellent condition and is able to be recycled for reuse to create “hills” in the park. Geofoam will also support the base below new paths for bikers and walkers to get through to the lake paths.
Maggie Daley Park Rendering

Maggie Daley Park Rendering

The site itself now has the required EPS Geofoam blocks stock piled and ready for installation. In the days to come the installation of the acres of Geofoam will be seen on the bottom right hand side of THIS JOBSITE CAMERA.

Bob O’Neill, president of Grant Park Conservancy, in an article from the Chicago Sun Times called the park “more natural and much more informal” than Daley Bicentennial Park. And very kid-friendly, featuring a three-acre play garden, ice rink, climbing walls, a skating rink in the shape of a ribbon .“You’ll be able to walk up hills and see the lake,” O’Neill said. “When this is done . . . it’s going to be a much more green, sort of organic flow. Whereas Millennium Park is more structural and formal, this is more nature-oriented.”

Expanded Polystyrene (EPS) Geofoam Vs. Traditional Fill

Public Works_2013 cover photo

2013 Public Works Magazine

Developed in the 1960’s as an engineered geotechnical material, expanded polystyrene (EPS) geofoam performs well in numerous applications and was designated by the Federal Highway Administration (FHWA) as a “priority, market-ready technology” in 2006.  As outlined in the spring 2013 Public Works magazine annual reference “Manual”, geofoam is 100% recyclable and non-toxic and it’s lightweight fill is used to reduce vertical stresses beneath embankments and lateral stresses on retaining walls, abutments, or foundations.  

Read more in the Public Works magazine:

  • geofoam defining properties
  • how to choose a geofoam supplier
  • per-cubic-yard costs of various fills
  • public works applications
  • key benefits
  • EPS goefoam cost vs. other fills

Read more on Geofoam:


Nico Sutmoller, Insulfoam Geofoam Specialist

Nico Sutmoller, Insulfoam Geofoam Specialist

Contact Nico Sutmoller, Geofoam Specialist

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