Concrete Lifting Foam Strength

Have Questions about the Strength of Concrete Lifting Foam?

Sometimes we receive questions or comments (mostly originating from mudjacking companies) regarding the foam used for raising concrete.  Some people asked if the concrete lifting foam is weak, mushy or strong enough to be effective.  We are here to provide solid facts that polyurethane foam injection is extremely strong and highly effective. If a mudjacking contractor tells you polyurethane is “not strong enough” for concrete raising, this statement is not based upon science, experience or fact.  Mudjacking contractor statements such as these are simply tactics used to misinform and ultimately sway a potential customer’s decision.

Polyurethane:  Foam Developed for a Specific Purpose

Polyurethane concrete lifting foams are developed and manufactured for the specific purpose of raising and supporting concrete. Polyurethane lifting foams are very strong and have a long track record as high-performance repairs. Many Department of Transportation (DOT) projects required the use of polyurethane over any other alternative material.  In fact, during the summer of 2014, right here in Chicagoland, portions of a 42 mile stretch of Illinois’ I-294 had dropped anywhere from 1/2″ to 5″. These heavily trafficked portions of the highway were repaired with polyurethane foam. This particular I-294 DOT project did not allow mudjacking as a repair option.

Just How Strong is Polyurethane Lifting Foam?

Polyurethane lifting foams create an abundant amount of lifting power to raise settled concrete.  They provide enough strength to support a slab enduring just about any load. To demonstrate this, we selected various items you might find on a concrete slab. These items range from a typical person to a vehicle as heavy as a Sherman Tank.  We’ve looked at potential dimensions and weight of each item and then estimated the weight and size of the concrete slab required to support the item.  Next, using the laboratory-verified performance specifications of our lifting foams, we calculated the actual weight the foam could support before failing.

 Average PersonMotorcycleCarPickup TruckSemi TruckSherman Tank
Slab Dimensions (ft)1' x 1'3' x 6'6' x 10'6' x 12'8' x 20'9' x 20'
Slab Area (sqft)1186072160180
Weight of Item (lbs)1607003,8005,00020,00066,800
Weight of Slab (lbs)501,3504,5005,40012,00017,982
Total Load (lbs)2102,0508,30010,40032,0084,782
Weight Capacity (lbs) of Slabs Supported by 1-Inch Polyurethane Lifting Foam
Slab Dimensions (ft)1' x 1'3' x 6'6' x 10'6' x 12'8' x 20'9' x 20'
RR-201: Residential Grade Foam3606,48021,60025,92057,60064,800
RR-401: Commercial Grade Foam1,08019,44064,80077,760172,800194,400
Polyurethane Provides Excessive Support for Most Applications

In the table above, it is easy to see why polyurethane foam designed for raising and supporting concrete is more than adequate for nearly every situation.  In the case involving a Sherman Tank please note the following.  The tank weighs 66,800 pounds and would require a slab 9 feet wide, by 20 feet long. We’ve assumed a slab approximately 8 inches thick which would weigh an additional 17,982 pounds. Combined together, the total weight of the slab and tank would be 84,782 pounds. Our Formula RR-401 lifting foam for Commercial applications would support over 194,400 pounds of load. This is over 2 times the weight of the load!

The Bottom Line Regarding Lifting Foam Strength

The bottom line is this:

  • Lifting sunken concrete with polyurethane foams formulated for raising and supporting concrete is a proven mature technology.
  • Polyurethane lifting foams are specifically required for many DOT projects.
  • Claims that polyurethane injections are not “strong” or long-lasting are not based on experience, fact or history.
  • Raising concrete with polyurethane is a smart choice when considering health, safety and the environment.