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Foam Jackers
Claiming poly-foam an economical alternative to conventional Mudjacking…is False & Misleading

  • Poly-foam is far more costly than the natural clay/sand materials used in Mudjacking, which is why poly-foam contractors avoid estimating large cavity filling conditions, such as a front step cavity or a wash out;
  • Mudjacking projects will always be less costly, will take less time, and will be better supported than any poly-foam jacking project;
  • While poly-foam is a lighter product, less weight is of no benefit to a sub-grade, which is typically backfilled with a clay base material and compacted; Further, poly-foam projects lighter due to all the cavities left behind under the slab;
  • Poly-foam jacking cavities provide unsanitary rodent habitants under the slab, which will ultimately result in damage to the adjacent landscaping;
  • Mudjacking does not require heavy equipment;
  • Mudjacking will support a load equally as soon as poly-foam, therefore driveways can be driven on within a few hours. However, since poly-foam jacking projects creates voids and cavities, it would be advised to never use a poly-foam jacked driveway again;
  • The use of larger grout holes less than (2 in.) are required to raise and properly monitor the cavity filling progress under the slab. Monitoring cavity filling is not possible with poly-foam, which it cannot fill anyway;
  • While traditional Mudjacking uses larger holes, there will be fewer holes required, whereas foam requires more than twice as many smaller ¾ inch holes;
  • Poly-foam jackers will not discuss the extent of the cavities left unfilled, which are conveniently concealed by the concrete slab;
  • Should further sinking occurs, subsequent injections with poly-foam will simply result in another foam blob on top of the first foam blob, basically creating a snowman shaped poly-blob under the slab, that makes the concrete slab unstable.
  • Health & safety is jeopardized with poly-foam applications that involve a compilation of environmentally hazardous substances being injected around your home;
  • While poly-foam chemically expands in all directions, its setting time can only fill a 12-inch glass cube before the material solidifies and stops flowing. Therefore it is standard to have 50 to 80% of the space under the concrete slab left as cavities.
  • Mudjacking material clay/sand does not set up quickly and will remain pumpable and flowable during the project to ensure all cavities, created by the raising process, are filled in order to hold heavy loads without cracking
  • As mentioned above, once water gets into the foam pores and freezes it will result in decomposition that breaks the foam into pellets that can be easily eaten by birds, other animals, and pets.
Typical Support Lump Under Slab Cavity Surrounding
Foam Clean?
Typical FoamLump Under Slab Cavity Surrounding
  • Poly-foam will become deteriorated when mixed in ponding water under a slab, whereas Mudjacking will chase any ponding water out from under the slab.
  • Should your concrete slab be removed in the future, any poly-foam blobs and concrete with foam adhered, will all have to be handled and disposed of as a hazardous waste.



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Mudjacking vs Foam Jacking

Two part poly-foam injection procedures will leave your concrete slab propped up on foam blob, leaving 50 to 80% of the under slab area as open cavities.
Concrete slabs, such as driveways, are expected to support heavy vehicles and in order to do so the entire slab must be properly supported, with no cavities under the concrete slab.

However, the poly-foam injection process will result in differential uncontrolled support blobs scattered haphazardly below the slab, surrounded by cavities, which will result in unnecessary cracking and breakage when the precariously supported slab is back in service.

A consistently filled base using poly-foam injection is simply not possible. Foam can only fill 12-inch glass cube (poly-foam advertizing), because the two-part foam injection system set up in 5 seconds or less, therefore only a blob is created, which will take on the shape of a snowman should a second or third injection is required.

These poly-blobs conveniently out of the customer’s sight, under the concrete slab, are not structurally reliable, especially when your concrete slab was poured thin. If this is the case it becomes very important to insure the entire slab is universally supported. A concrete slab is typically referred to as a “slab-on-grade” for specific reasons.

The only true slab jacking process proven over decades is the conventional Mudjacking method that ensures universal support with no voids or cavities. There is no substitute or better method.

Poly-Foam Facts:

  • Polyurethane involves two chemicals that must be proportionately mixed at the right temperatures. If this mixing is not done correctly the resulting foam will easily crumble and deteriorate leaving the concrete slab unstable;
  • The two polyurethane chemicals are mixed together directly under the concrete slab, should there be any foreign substance present, such as water, the resulting foam will deteriorate quickly and the concrete slab will become unstable;
  • When Poly-Foam products burn Carbon Dioxide and Hydrogen Cyanide is created as a sooty flame, which is dangerous if inhaled;
  • The recent Grenfell Tower fire in London, UK was compounded by the poly-foam cladding, which is now a banned product;
  • Poly-foam dissolves in hydrocarbon based solvents such as: toluene, acetone;
  • Rodents can eat through poly-foam products;
  • Freezing poly-foam with water in the pores will cause it to breakup into pellets, to be eaten by birds and other animals, undermining the stability of the slab;
  • Poly-foam products are banned as a food container in many states in the USA;
  • Poly-foam is not accepted as a recycling material, should you remove your concrete any underlying poly-foam will have to be handled as hazardous product.
Phoney Foam Promo
Hazmat Filter
Hazmat Filter



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Foam Jacking Problems

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Foam Jacking can lead to many problems in attempting to raise concrete in Regina.
There are better and safer options.

  • Cavities & Voids… Most concrete slabs overlay a significant void condition that must be filled prior to being able to raise the concrete slab. Voids are commonly found along a foundation, due to the consolidation of loose backfill used when the foundation was constructed. This settlement zone can be as much as 18 inches, or more, which would require a large volume of foam to do the job correctly. Filling such voids and cavities is beyond the capability of foam that simply sets up too fast to properly fill any sized void.
  • Costs… A simple question to pose is…what jacking material costs more, polyurethane foam or mud? The answer to this question explains why it is important to get a comparable Mudjacking price, and not simply accept the faulty premise promoted by the foam jacking company, that foamjacking is less costly than Mudjacking, when it is many times more costly.
  • Cost example… On a Gunner LiftCrete estimate to raise the customer’s patio, driveway, the walk to the front step, and fill the cavity under the front step, the cost was $2,500.00. The customers had also received a foamjacking estimate on the same areas for a shocking $9,000.00, minus front step fill. This cost variance is effectively robbery.
  • Appearance… A foamjacking company will also mislead a customer into a false believe their foam injection process is less damaging because they use access holes at half the diameter of the Mudjacking access holes. What they fail to advise is that they require twice as many holes, and even more…because foam is non-flowable and hardens in 5 seconds. Mudjacking access holes are 4 to 6 feet apart and can be finished to closely match the existing surface, or can be imprinted. Furthermore, the larger diameter Mudjacking holes allow for monitoring for proper void filling below the slab, something foamjacking completely neglects.
  • Experience… is important to ensure the settled concrete slab is properly supported during the raising process, which is critically important to both methods, if unnecessary damage and proper elevations are accomplished. Mudjacking in Regina has been raising concrete slabs for now 40 years, by Gunner LiftCrete, whereas foam jacking is a new process that has only been advertized as a concrete slab raiser over the last couple years. Basically, foamjacking will always be a trial-and-error process that will never survive the test-of-time necessary to acquire any slab raising expertise. Foamjacking has been a bad idea from the start, and based on its history foamjacking will always be a bad idea.
  • Control… a big issue with raising concrete slabs, because foam sets in 5 seconds there is no ability to carefully nudge the slab into position, which Mudjacking does permit with material that is flowable during the project. Foamjacking has a tendency to leave a slab under jacked or over jacked an over-steering due to the quick solidification of the foam. Rarely is a foam jack slab ever raised to original elevations, simply because the injection process is too erratic, uncontrollable, and subject to trial and error guesswork.
  • Cavity Fill… Does foam completely fill all cavities? From foam jacking installation videos, it is clear the foam product has difficulty exiting along the edges or up through cracks and construction joints, which proves the foam jacking process results in uncontrolled pillow formations with a surrounding cavity. This type of formation is not conducive to proper structural support or in damming off water migration that prevents it from ponding under the slab or undermining the adjacent foundation.
  • Stops Water… Mudjacking uses a clay-base material mixed with cement and water to create a grout like material that completely fills the large cavities as well as the tapering cavity created by raising the slab, which is necessary to withstand heavy vehicles, and acts to seal the underside of the concrete slab preventing wet/dry and freeze/thaw slab shifting, creating slab stability. This is an important feature Mudjacking provides and foam jacking pillows do not.
  • Important Condition… Often a cavity under a front step must be filled prior to raising the adjacent front walk. Otherwise the ground around the step will slough-in to undermine the front walk’s support. Any lifting of the walk will be short lived. This step cavity typically requires 2-3 cubic yard of material, something impossible for foam jackers, but an easy fill for Mudjackers.
Phoney Foam Promo
Typical Foam Mess
Hazmat Dress Code
Hazmat Dress Code
  • Touch-Up Requirements… There is a possibility the ground under a mudjacked concrete slab will dry and settle, requiring a later Mudjacking touch up. When this occurs with a Mudjacked concrete slab, the former access holes can be re-used and the slab can be adjusted to very fine increments. Whereas foam expansion does not have fine control and will easily exceed the required adjustments. The guesswork involved with quickly expanding foam is a major control issue associated with all foam applications.
  • Health Issue… The clay-based Mudjacking materials can be re-used as landscaping fill, whereas polyurethane foam cannot be re-used or recycled, and must be disposed as a hazardous material, not unlike asbestos.
  • Rodents & Insects… Foam jacking fails to block out rodents and insects, these critters can simply burrow into and through the foam material. In fact the warmth of foam insulation will encourage such an infestation. Contrary to Mudjack material containing cement, this grout like material will obstruct rodents, and insects, to completely barrier off areas, under steps and crawl space grade beams.

The above describes only a few of the polyurethane foam jacking disadvantages that must be seriously considered by property owners deciding to raise their settled concrete slabs. Comparisons between Mudjacking and foam jacking will clearly show a foam product is not the right approach to properly filled and universally supported concrete slabs, when long-term reliability is required.



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Liquid Backfill
Grading Investment Assures a Stable and Dry Foundation Diffusing a Structural Time Bomb

liquid backfill around foundation

Gunner Corp is proud to have been featured in Refined Lifestyles spring homes edition.