Over my many years of consulting with customers on jobs, I have pumped, shot, spilled, splashed, sprayed, poured and injected polyurethane foam into every imaginable type of concrete structure known to man. Most of it has ended up where it was supposed to go. But some of it did not.

Some of it ended up on my clothes, my skin, and my hair. That never bothered me (well, maybe the resin on that brand new button down shirt bothered me a little). What is really frustrating is when it stains the concrete you are trying to fix. Your job is to repair something for your customer, and if you are not careful, you can make it look worse than before.

A few years ago I asked our chemist to develop a water based solvent for cleaning out two component impingement style injection guns (such as our MixMaster Pro gun). I wanted the product to be water based so that it could be dispensed directly into the environment with no negative effects. I also needed it to be thick enough to push reacting foam out of the gun.

After I saw what he came up with, I realized it could probably be used as a barrier to prevent polyurethane from staining concrete. After a little testing and tweaking, I realized it would work.

AP Flush 125 is a concentrated product that you can mix with 3-5 parts water. It can be sprayed onto concrete, wood, metal, or plastic and creates a barrier layer that prevents polyurethane foam from sticking to and staining the surface. You can brush it on or spray it on with a pump up garden sprayer.

Our AP Lift customers spray it right out of the MixMaster Pro gun onto concrete surfaces as they are moving from injection point to injection point. They also saturate cracks and joints that foam may come out of. This has the dual protection of keeping stains off the concrete and helps reduce binding of the concrete that can impede the lifting process.

On hot, sunny days you may have to apply it again if the water evaporates out of the system, but overall it really works wonders. We have used it on lifting jobs, soil stabilization jobs, and leak seal jobs. Now the spray foam insulation contractors are starting to use it to protect surfaces adjacent to their work areas.

Next time you are using polyurethane foam on or near a surface you don’t want your foam to stick to or stain, try a pail of AP Flush 125. One pail of concentrate can give you up to 25 gallons of protection.

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After three decades in this industry, I still find myself in awe of what polyurethane foam can do.  From sealing massive dam leaks to stabilizing airport runway slabs to lifting entire buildings – the feats contractors achieve with this stuff is astonishing.  Yet some people who are new to this technology have a hard time understanding how a mere “foam” can be ideal for these most demanding of applications.  Or maybe they wonder how safe it is. 

The irony is, whether you think you are “new” to this technology or not – you’ve been surrounded by polyurethane all your life.  Sometimes an understanding of the past can provide more confidence for moving forward into the future.  So if you can’t quite grasp how “foam” has been developed to the point that it can lift a building – or you wonder how safe it is – pay close attention to this story.

Dr. Otto Bayer first made polyurethane foam in Leverkusen, Germany in 1937.  Polyurethane was initially used as a cheap replacement for rubber.  Widespread use began in World War II, when many other materials became scarce.  Polyurethane use quickly spread as a key component in many products, from specialized paper to protective military garments to gloss finishes and protective coatings.

In the 1950s, many companies such as DuPont, BASF, Dow, and Union Carbide started producing polyurethane for an even wider variety of applications including adhesives, insulation and foam upholstery cushions.  In the 1960s the Bayer company (no relation to Dr. Otto Bayer) exhibited an all-plastic car, parts of which were made with polyurethane. 

In the early 1970s, the introduction of polyurethane skateboard wheels as a replacement for the old metal ones completely revolutionized the sport, as the new wheels allowed for high impact activities such as jumping off of ramps.  In the 1980s, the first mass produced plastic-body automobile – the Pontiac Fiero – was made with the use of polyurethane technology.

Today polyurethanes can be found in an infinite amount of products including furniture, clothing, shoes, beds, moldings, etc.

In the 1960s, 3M Company in the U.S. and Takanaka in Japan both introduced polyurethane grouts.  3M’s product was called Elastromeric Sewer Grouting Compound.  As the name indicates, it was intended for use in underground utilities.  Takanaka’s product was called Takanaka Aqua-Reactive Chemical Soil Stabilizer (TACSS).  As the name indicates, it was intended for use in soil stabilization projects.  In the early 1980s, DeNeef obtained the rights to TACSS and began distributing polyurethane grout worldwide.  By the mid 1980s, there were almost a dozen manufacturers of polyurethane grouts.  I got my start pumping 3M 5600 to seal cracks in the Atlanta subway system back in 1985.  I was amazed at what it could do back then, and I am still amazed at what our products do today.  3M exited the business many years ago.

In the last few decades, polyurethane grouting has become a widely accepted method for sealing leaks, stabilizing soil and lifting slabs.  Many innovations have been made, including closed cell hydrophobic polyurethanes and the use of two-component foams in geotechnical engineering.  Polyurethane’s advantages over the old school approach of cement grout repair is covered thoroughly in our blog post Polyurethane vs. Cement for Slab Jacking.

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In a recent media interview, I was quoted as follows: “Ultimately, the customer is the property owner, somebody who’s got a problem. Even though we’re selling to contractors, we kind of all have to be on the same page.” That view has motivated us to pay close attention to what contractors, engineers AND property owners are most concerned about regarding the use of polyurethane. Over the years, we’ve noticed three main questions that arise over and over again:

1. Are the polymers strong enough?
2. Are they easy to install?
3. How quickly can the job be finished?

So we’re going to take a look at each of these three core issues in detail…

Powerful Polymers

Concrete Leveling Foams

In my blog post Slab Jacking With Polyurethane Foam – How Strong is Strong Enough?, I point out that the National Home Builders Association and the International Building Code list stiff clay as having a 4,000 lbs per square foot load bearing capacity and crystalline bedrock as having 12,000 lbs per square foot capacity. Our lifting foams have load bearing capacities of 7,200 to 14,000 lbs per square foot after curing in a free rise state. 

When Alchemy-Spetec foams cure in a confined state underground, that bearing capacity has been known to be even stronger. Testing data in the lab shows that our lifting foams will increase in compressive strength: In a space confined 25% by volume there will be an increase of 31% in psi and in a space confined by 75% there will be a 79% increase in the psi.

The Alchemy-Spetec lifting foams are used to level airport slabs supporting jumbo jets, heavy equipment, building slabs supporting tremendous loads, and even railway slabs supporting the heaviest freight trains.

Leak Seal Resins

Alchemy-Spetec leak seal resins have been used in many applications, including shutting down a 2-million gallon per day leak at a water treatment plant. The leak was reduced from 1,700 gallons per minute to just 10 gallons per minute (attributed to the many vintage valves and fittings that are still present at the plant). They are also used in other applications such as curtain wall grouting.

Soil Stabilization Resins

Unstable, eroded, or loose soil around infrastructure can result in settlement and damage to the structure. Voids can be filled, seawalls remediated, soil consolidated, and water migration halted by injecting the soil with Alchemy-Spetec soil stabilization resins. In my blog post Soil Stabilization Products Prevent Cave In Beneath Busy Intersection, I profiled a powerful example of AP Fill 700 in action. Inspectors in Orange County, Florida found a depression in the middle of a busy intersection that was due to an underground sewer line that wasn’t sealed. Water and eroding soil were infiltrating the sewer line causing the road to slowly settle. The resulting voids around the drainage structures had the potential to grow larger, eventually resulting in a complete cave-in of the roadway. A point repair was done from within the leaky pipe to stop the infiltration but they feared it was only a matter of time before the road gave way. We devised a solution for their crew to use the versatility of AP Fill 700 as both a permeation and void filling grout.  To keep the lane closure down to a bare minimum of time, the project was successfully completed on two separate Saturdays. The voids were filled, the loose soil was solidified, and only minor asphalt patching was required to make that area smooth for traffic again.

Orange County Utilities Supervisor Paul Morrison has been enthusiastic about AP 700 since the first time he tried it out on a severe manhole leak, when he had this to say…

“Based on our extensive prior experience, we expected to use at least five to ten pails to stop this leak. With Alchemy-Spetec material we were able to do the job with 1/10th of that amount. Their product will save our crews a lot of time and labor, and save the taxpayers of Orange County a lot of money.”

AP Soil 600 is one of the most versatile permeation grouting products on the market. It can be characterized by its single component, moisture activated, hydrophobic, and low viscosity qualities. It can fortify sandy soil to strengths approaching 2,000 psi.

Painless Procedures

As I never fail to point out, application procedures for Alchemy-Spetec products are relatively painless. The installation process is very clean compared to replacing the structure or repairing with cement grout.  Polyurethane is lighter than cement, so it doesn’t sink. Alchemy-Spetec products do not shrink after installation. The closed cell structure makes these resins impermeable. 

Rapid Results

Application of polyurethane is usually less expensive than replacement. Polyurethane concrete repair is also less time consuming. Any structure repaired with Alchemy-Spetec products is usually ready for use 45 minutes after application.

There you have it – the three most critical issues for contractors, engineers and property owners regarding polyurethane concrete repair. By staying focused on these concerns we constantly remind ourselves WHY we do what we do. We do it for YOU.

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As a technical consultant, I often assist customers when they're put to the test with difficult jobs. That's why we go out of our way to provide the powerful polymers and painless procedures they need to achieve the rapid results those projects require. For an in-depth dive into what we mean by powerful, painless and rapid - see this blog post I wrote awhile back. Then watch the video below to see powerful polymers, painless procedures, and rapid results in action... 

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Poor compaction, water erosion, broken pipes, and organic material in the soil can all lead to settling of a foundation or a roadway.  Traditional slab lifting can bring concrete and structures back into place but it doesn’t necessarily address the underlying issue or guarantee a long term fix.  Other methods of addressing deep soil issues require heavy equipment, extended down time, and collateral property damage.  These situations create problems for property owners as well as opportunities for the elite contractors that know how to fix them.

Alchemy-Spetec offers a unique combination of high quality structural lifting foams along with the equipment and training needed to address deep soil issues. Now you can achieve soil densification and lifting on large projects with the smallest footprint and least amount of heavy equipment required.

The Deep Lift™ process is powerful, painless, and rapid. Deep Lift™ gets to the root of the problems in the soil, it brings the structure back to level, and accomplishes this with minimal imposition or downtime to the property owner.

For a detailed explanation of the process, watch the animated video below... 

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According to the Guinness Book of World Records, the honey badger is the world's most fearless animal. With ultra-thick skin and top of the line fighting instincts, this creature is not to be messed with. It boldly goes where similar animals consistently fear to tread. 

Let's take a deep dive into why Alchemy-Spetec's smallest slab lifting system, The PolyBadger, is named after this incredible animal. As Alchemy-Spetec regional manager Andy Powell mentions in this previous blog post...

"The Alchemy-Spetec PolyBadger lifting system is tough and compact. This system is an affordable entry-level slab lifting option for new contractors, as well as an extremely portable addition to the experienced contractor’s arsenal. The PolyBadger is a lot less expensive than your standard 20-foot trailer rig. The setup is simple and requires minimal equipment. The entire system can easily fit in the back of a pickup truck!"

Like the Honey Badger, the PolyBadger lifting system is both Tough and Compact

The PolyBadger slab lifting system is durably built and designed to go where other lifting systems simply cannot venture. Here's a quick rundown...

• The PolyBadger is smaller in size than most of the competition, at 30" wide and 48" long. Now that's what you call portable!
• This is one of the few systems powered through a common 120-volt wall outlet (vs the usual 240-volt requirement). Compatibility with common wall outlets exponentially increases your location possibilities.
• Essential elements (heaters, electronics, auto calibrator) are self-contained and protected in the cabinet for extra portability.  
• The cabinet is constructed from powder coated carbon steel and the frame is constructed from carbon steel box tubing. 
• The entire system is very maneuverable, resting on two swivel and two fixed 6-inch pneumatic castor wheels.  The wheels are are filled with light weight polyurethane instead of air, so they don't go flat. 
• The hose is built to last with a Teflon core and a stainless-steel braid. The system can operate with up to 200 feet of hose.

One last very important point:

Honey badgers are also mentally tough. They've been known to build stools with rocks in order to get over walls even break through locks on food freezers! Nothing stops them! The PolyBadger system's auto calibrator provides similar qualities to keep it going through thick and thin. As Andy Powell mentions in this previous blog post...

"The genius of the PolyBadger is the auto calibrator. It keeps the flow of A-side and B-side slab lifting material on ratio, eliminating the possibility of crossover clogging in the gun or the whip hose. The two low-pressure transfer pumps and auto calibrator are literally the only moving parts in the whole system. That means less downtime, less maintenance, and more productivity on the job."

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AP Lift foams have an inverse relationship between expansion and strength. The more they expand, the less compressive strength they have. The less they expand, the more compressive strength they have.

AP Lift 420 has the highest expansion which means it is the most economical product in terms of filling a void. It also has the lowest compressive strength.

AP Lift 475 expands less than half the amount of AP Lift 420, but the compressive strength is 370% stronger.

Understand that these expansion rates and compressive strengths are based on free rise foam. Free rise means that the material is allowed to expand with no resistance (example: foam that was mixed and expanded in an open cup). In most cases you are injecting these products into soil or into a void that is closed off on most sides. The foam meets resistance as it expands. The resistance reduces the amount of expansion and therefore increases the compressive strength. How much expansion is reduced varies from job to job and is influenced by soil conditions, void size and shape, quantity of material injected, etc.

Although each product can be used in multiple applications, here is a quick guide to product selection:

AP Fill 420 – Filling large voids, Deep Lift process
AP Lift 430 – Residential slab lift applications
AP Lift 440 – Highway concrete slab lift applications
AP Lift 475 – Heavy duty slab lift applications

Note: All of these products are designed to work in wet environments.

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I met with a contractor today who does residential slab lifting and for some reason we ended up talking about incoming leads and how to prequalify them. Every slab lifting or foundation contractor has experienced driving for hours to look at a potential job that turns out to be a wasted trip. Every property owner has probably taken time off from work to meet a contractor who wasn't the right fit either. It's not anyone's fault but it can be avoided, saving both the contractor and the property owner valuable time.

I thought it might make a good blog topic: how to technically evaluate an incoming lead before sending a salesperson out to do a site evaluation and estimate.

Here are some prequalifying questions to consider asking a property owner:

1. Can you text me or email me a picture of the sunken slab, stairs, pool deck, etc?
   This will tell you a lot because pictures may reveal that the concrete is too fractured for lifting. If so, you'll save yourself a trip. You may also notice some impediments to the lifting process, like brickwork or bound slabs. Pictures may also reveal the cause of the problem, like erosion caused by poorly directed roof drains. With this info you can start developing a plan right away (if you decide on a site evaluation).
   
   
2. How long has this been going on?
   It's important to ask the owner how long the settling has been going on. If it is recent and happening at an accelerated rate, that may indicate an entirely different problem than a slab that has settled over a period of years. Settling related to erosion and compaction issues, as well as buried organic material, usually occurs gradually. Broken pipes and sinkholes, on the other hand, usually cause rapid sinking and need attention immediately. It might be better in these cases to recommend a plumber or geotechnical engineer first before going to look at the sunken slab.
   
   
3. What information is available?
   Has anyone else been out to look at it, what were their findings, and are there any available engineering reports? This is pretty self-explanatory. Information is extremely helpful on geotechnical jobs whether it is data from ground penetrating radar, soil borings, penetrometers (DCP), etc. Even local knowledge of the property can be very helpful. Were any new buried utilities put in, or were there any adjacent property developments where de-watering was incorporated? This information may also keep a contractor from making a mistake by quoting on something they are possibly not qualified to execute. As Clint Eastwood (I wish) once said, "Slab lifting contractors must know their limitations".
   
   
4. Is this property for sale or going on the market?
   This is a sensitive subject to write about because some of our contractors do get leads from real estate experts and property owners. Often there has been an inspection and the report indicates a tripping hazard or a settling issue. The owner and potential buyer will use the repair estimate to negotiate on the sale price and no work ever gets done. It's fair to ask if this is just a quote required for the sale of the property or if there is a real intention of fixing the issue.
   
   
5. How far down is the slab or foundation?
   It takes a certain amount of polyurethane to lift a slab. Sometimes you have to accept that a slab that is down 12 inches may be more affordably replaced than lifted. However, sometimes a slab that's down several inches may be in a location where demolishing it and bringing in new concrete is disruptive. The polyurethane may be the best and only answer; one of the things that makes it great.
   
   
6. Are you the owner?
   I can appreciate a renter's concern about concrete settling but you obviously need to talk to the owner. There have been many site visits made on request of a renter to be used as a complaint against the owner. I'm not saying these are illegitimate issues but they deserve to be evaluated carefully.

In addition to asking the questions above, you'll want to keep these two points firmly in mind:

1. Stay focused on the repair.
   In the concrete repair, soil stabilization, and slab lifting business, contractors are often called in when something is going wrong. Something is leaking, sinking, cracking, etc. When evaluating a job site it is always a good idea to consider what you say and what you propose to the client. It is good policy to focus on the repair rather than give your opinion on why something happened or why the engineer recommended a repair method. That is context sensitive obviously, but sometimes there are litigation issues that could be pending.
   
   
2. Make sure they know you're using polyurethane rather than cement grout.
   Last of all it's always a good idea to make sure the client understands you are using polymer technology and that you are not a mudjacking outfit. Polyurethane slab lifting with the AP Lift series of foams is cleaner, permanent, it doesn't shrink or wash out - and our certified contractors are better looking, ha ha.

Want more information on polyurethane slab lifting?

Slab Jacking with Lighter Material Prevents Further Sinking

We are often asked about the biggest advantages of lifting settled concrete slabs with polyurethane foam vs. cement grout.  One of the biggest advantages is the weight.  Depending on the product, the density of structural polyurethane lifting foam is between 3 ½ and 5 pounds per cubic foot.  The same volume of cement grout weighs 140 pounds per cubic foot. This translates to 30 to 40 times more added weight using cement vs. polyurethane. By using lighter weight materials, you are giving yourself a much greater chance for long term success.  (Polyurethane is strong enough to support any structure, as explained in our earlier blog post How Strong is Strong Enough.)

Concrete Lifting with Polyurethane Creates Less Mess

Another advantage of using foam is the size of the drill holes.  Drilling holes for foam is quick and easy, requiring only a 3/8” hole to inject through.  For mud jacking you are drilling injection holes ranging from one to two and a half inches.  This takes longer, does more damage to the concrete, and the drills and drill bits are more expensive.  With mud jacking there are the additional problems of messier works sites and disposal of unused mixed cement.

Mudjacking with Cement Requires Longer Cure Times

The final advantage of foam over cement is time.  All of our AP Lift series products reach 90 percent of their final strength in 15 minutes and are fully cured in less than a day.  Literally, as soon as you are done packing up your equipment the foam under the slab is ready for traffic.  On the other hand, cement grout can take days to reach final cure.  Having immediate load bearing traffic is especially important for facilities such as warehouses that run 24/7 and need to use the lifted area as soon as the job is complete.  

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Aim for Opportunity

In this article, we'll identify opportunities and markets where slab jacking is needed. Three main markets we will take a look at are Residential, Commercial / Industrial, and Transportation.

Residential Slab Jacking

The residential market offers tremendous opportunities for the slab lifting contractor. Obviously, there are driveways and foundations. These can all sink for various reasons such as water runoff, excess weight, and poor compaction. But look a little further; this year alone we have had calls concerning the following areas: patios, outbuildings, pools, and porches. And don't think residential only includes houses. I'm not officilally saying that construction companies building condos and apartments would bury trash that would later cause settling issues; I'm just saying....

Commercial / Industrial Slab Jacking

Because the scenarios for slab lifting are endless for non-residential slab lifting, I am going to lump Commercial and Industrial together. Concrete parking lots are often lifted now instead of replaced. The same goes for busy warehouse floors; lifted and back in business in hours, not days. Another place to look is slabs beneath equipment; they are not always originally designed to support heavy loads but the equipment ends up there anyways. Anywhere there is a transition there could be a lifting opportunity. From inside to outside, from slab to slab, from parking lot to parking deck, and any areas where there is water runoff.

Slab Jacking for the Transportation Sector

Last but not least, take a look in the transportation sector. Our highway and road building contractors do a great job. But in the miles and miles of asphalt and concrete, there are going to be some settling issues. Look again at transitions, from highway to bridge (the bridge approach slab) is a good example. Think airport taxiway slabs don't ever sink? Wrong. Think slabs under railroad tracks don't ever need stabilizing and leveling? Wrong again. And the advantage for lifting with polyurethane really shines in this sector. Strong, fast, and back in business in hours, not days.

So get off your assets and go lift something.

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