Concrete slabs sink for a variety of reasons.  The result is an eyesore and possibly a trip hazard that could - in a worst case scenario - result in a serious injury, a law suit and/or death.  Lifting slabs with polyurethane foam is safe, fast, and economical. 

Property owners and managers should learn how to deal with these liability issues NOW with the latest concrete repair techniques and preventative measures. If you’re a contractor, you need this information because it’s critical for YOUR customer – the property owner.

Common Danger Zones

Since an ounce of prevention is worth a pound of cure, it’s helpful to know where to look for potential sunken slabs, especially if you own or manage a large variety of properties.  As a contractor you’ll want to focus on these types of sites when looking for potential customers.  The three main property categories that tend to have slab settling issues are:

• Residential (single and multi-family).
• Commercial and industrial.
• Warehouse and logistical.

Residential sites can often have driveway, sidewalk, patio, or garage floor issues.  Commercial and industrial sites often contain showroom or factory floors made of concrete slab.  Warehouse and logistical centers can contain huge floors with massive square footage.  Because warehouse floors are often raised off the ground to incorporate a loading dock, they are particularly vulnerable to the formation of dangerous voids underneath.

Causes of Slab Settlement

Let’s take a look at why slabs sink in the first place. There are at least six main reasons:

• Equipment on surface putting too much weight on slabs.
• Erosion due to natural causes.
• Leaking drain pipes and water mains.
• Improper site drainage or poor water management from downspouts and gutters.
• Poor soil consolidation/compaction.
• Old trash pits from the original construction phase that were too close to the structure.

Familiarity with these common causes of slab settling can help a lot when attempting to diagnose the exact cause at a specific location.  For more, see our blog post series The Causes of Unstable Soil.

Results of Neglect

After becoming aware of a slab issue, the property owner has a critical choice to make.  To repair or not to repair – that is the question.  Neglecting a repair can have huge implications.  Here are a few possible results of neglect:

• Damage to vehicles and equipment.
• Unlevel racking and storage.
• Personal property damage.
• Sinkholes.
• Trip hazards.
• Employee injuries.
• Limitless liability issues.

Read that list a few times and seriously consider the very real possibility that one or more of these events may occur when a property owner neglects a slab repair.  As experts with many years in the industry, we’ve seen every one of these events unfold after a problem was ignored.

In the next installment of this two-part series, we’ll review the two most common methods for repairing a trip hazard aside from polyurethane, and then we’ll review the three most common types of slab repair with polyurethane: slab lifting, soil stabilization and void fill.

Want in-depth info on concrete leveling procedures and products?

This blog post explains how to develop a contract for a typical lifting job.  We’ll cover essential points such as Description of Process and Products, Scope of Work, Scheduling, Items Furnished by Others, Stipulations, Price, Warranty, Terms of Payment and Seeking Legal Counsel for Fine Tuning. 

PLEASE NOTE: This article covers situations that you may want to consider when preparing your contract.  It is not intended as legal advice, is not all inclusive, and has not been reviewed by any attorney.  It should not be relied upon as such.  Laws vary from state to state.  You should seek the advice of legal counsel licensed to practice law in your state before finalizing your contract documents.

Brief Description of Process and Products

It’s important to start by outlining the process and products you’ll be using.  Some of our current customers use blurbs like this… 

The slab lifting process consists of the injection of expansive high density polyurethane foam underneath the concrete.  This foam is manufactured by Alchemy-Spetec of Tucker, Georgia.  This high density foam has a quick cure time of 15 minutes to 90% weight load capacity, does not shrink, is hydrophobic, creates a moisture barrier, and is lightweight.

Scope of Work

Next you’ll want to be very specific about the scope of work for the project.  Use this section to explain to the customer exactly which areas will be lifted and exactly how you estimated the amount of material you’ll need.  (For a refresher on estimating material, see our blog post Estimating Material for Slab Lifting Jobs.)

Scheduling

It’s important to spell out the order in which certain events will take place and the time parameters in which you’ll be able to do the work.  For example, you may cover points like calling the appropriate agency to locate underground utilities on site before the job starts, coordinating with the engineer (if there is one) during the job, and outlining the days and hours in which you typically work.  You can also let them know how long it will typically take you to begin the job after they give you the green light. 

Items Furnished by Others

In this section you can briefly list any items that you expect the customer to furnish, such as access to and from the work area, electricity, water, etc.

Stipulations

It’s critical to inform your customer and also cover yourself regarding anything and everything that could go wrong on a slab lifting job.  Unlocated plumbing pipes accidentally infiltrated with resin, cracks in foundations lacking steel reinforcement, cracks in slabs, etc.  Be clear about what you will and will not be held liable for. 

Warranty

Alchemy-Spetec warrants that our resin products will not deteriorate or shrink for a period of 10 years after the date of installation.  You need to decide what type of warranty you will offer on your labor.  Many of our contractors offer to replace any failed product for a period of 1 year at no cost to the owner, and then at a pro-rated scale after that.  Be sure to exclude any damage done by acts of nature such as floods, earthquakes, hurricanes, etc. 

Price

Spell out exactly how much you will charge for labor and how much you estimate materials will cost.  You may want to break down the material cost into a per pound amount, so they have an idea how much extra they will be paying if you have to use more material than originally estimated. 

Terms of Payment

Lay out the terms of your compensation, including an up-front deposit amount, how long the customer has to pay the balance.  Many of our customers insist on the balance being paid upon job completion, to avoid any collection headaches. 

Seek Legal Counsel for Fine Tuning

Again, it’s important to note that these are just general guidelines meant to assist you in constructing a contract of your own.  Laws differ from state to state.  Once you have a rough draft completed, we strongly urge you to seek the advice of legal counsel licensed to practice law in your state.  An initial rough draft combined with feedback and fine tuning from an attorney will get you to a solid standard contract that you can re-use for many jobs to come.

Want a phone consultation to discuss your concrete leveling contract?

Don’t Be Complacent When It Comes To Safety

For many years I have been a Technical Consultant for Alchemy-Spetec.  Prior to that, I ran a small crew doing polyurethane, and in some cases epoxy, injection for infrastructure repair.

All of the products I have worked with have some similar things in common both in terms of the product, and the application.  First of all, everything we work with is sticky and secondly, most everything we work with is pumped under some kind of pressure.

Sometimes on-the-job events remind you to always think things through, and to never be complacent or take anything for granted when it comes to safety.

Know Your Equipment

Although Alchemy-Spetec sells turnkey equipment systems for installing all of our products, often I am consulting in the field working with a contractor’s equipment.  Once on a seawall injection job, we started pumping and it became clear that material was not moving; somewhere there was a restriction.  Typically I work from the injection gun back to find out where the problem is.  On the Titan pumps I usually work with for leak seal jobs, you can switch the pump from “Spray” mode to “Prime” mode and it will relieve the pressure on the main line.  This wasn’t a Titan though, and after making that switch I thought I had relieved the pressure.  The injection gun was locked up and I thought material had set up in it causing the lock up.  Disassembling a fitting on the gun informed me otherwise as it blew off and shot high pressure resin onto my arms and elsewhere.  High pressure fluid wounds can cause long term complications and should be treated immediately if the skin is penetrated.  I made out okay with only wounded pride and a lesson learned. 

Think It Through

The old rule of thumb for carpenters is measure twice and cut once.  That is good to keep in mind for a lot of things in life, but it especially applies to our industry.  Sometimes we are pumping one-component resin and sometimes we are pumping two-component.  Other times we might be flushing out equipment or doing maintenance.  Think through everything you’re doing at all times.  Two-component equipment may have a lot of different valves and controls that need to be turned on or off in a certain order.  If you’re not sure consult the manual or pick up the phone and ask us.  Doing things out of sequence may not create a problem but there are times when it can.  That can lead to a mess or an injury.  When doing maintenance always follow appropriate lock-out tag-out procedures (LOTO).

Always Wear Your Safety Gear

When I had that high pressure blow out on my arms, it was a July day in FL.  Extreme heat and humidity were prevalent so I was wearing short sleeves as is common in the Sunshine State.  I had my safety glasses on which did prevent material from splashing in my eyes; however as I had to shave my arms later that day to remove resin, I wished I had been wearing a Tyvek suit.  Don’t cut corners on the PPE (Personal Protective Equipment).  Additionally, make sure you always have a first aid kit, eyewash station, fire extinguisher, and a safety plan in place.  For confined spaces, mandatory training and certification is not an option; it’s the law.  Don’t let your Christmas bonus evaporate because of a heavy OSHA or MSHA fine.

Pay Attention

There is plenty more to cover in a blog on safety; this one was really more of a reminder to both myself and everyone else to keep it in the forefront of our minds.  Safety is a group effort and requires everyone to be on the same page.  If you have more experience than the other person; pay attention to them and offer instruction and correction as necessary.  Watch out for each other and for your surroundings and you will establish the proper culture to succeed in this business.

Have More Questions About Contractor Safety?

Get ready for a thorough education in polyurethane slab lift/soil stabilization geotech products and applications on Friday, March 15th (March 14th is leak seal day), 2019 at Alchemy-Spetec HQ in Tucker, GA. You’ll get hands-on training from a technical staff with decades of on-the-job experience. Registration includes both days, but we’ll take a close look at the geotech curriculum in today’s blog post…

The schedule on Friday, March 15th includes education on the Alchemy-Spetec geotech product line, soil stabilization, slab lifting, the Deep Lift™ process, rig & mobile lifting systems, geotech accessories, soil testing (ground penetrating radar, penetrometer), pricing and estimating. There will also be live geotech demos, product mixing demos, and open discussions for sharing job related tips and solutions from the field.

Your instructors have years of experience providing technical support for contractors across the country. You can look forward to presentations, demos and/or discussions lead by Stephen C. Barton (President/CEO), Jim Spiegel (VP Sales & Business Development), Andy Powell (Southeastern Regional Manager), Anthony Sandone (Eastern Regional Manager), and Charlie Lerman (Western Regional Manager). 

Participants will receive a Samsung tablet loaded with leak seal training material.

The registration deadline is February 28th.

Sign up while there's still space available...

Just outside Saskatoon, Saskatchewan is a 12,000 square foot cement manufacturing plant that was being re-purposed for use as an agricultural seed sorting facility.  Built in the 1960s, the plant’s 10” thick, double rebar, 8000 psi concrete floors had settled.  An undetected broken water main on an adjoining property had been pumping thousands of gallons into the soil for years causing the floors to become independent of the footings which had sunk as much as 7 inches.  The new owner’s plan to demo the slabs – including some as large as 52 feet by 25 feet – and replace them came to a screeching halt when they proved to be too tough for even a track hoe mounted jackhammer.  All of the high tech seed sorting equipment was still sitting on pallets and couldn’t be installed until the floor problem was resolved.  With harvest season fast approaching, a mudjacker was hired to lift the slabs with cement grout.  This effort proved unsuccessful in that the final levels were not accurate enough, leaving the property owner in dire circumstances.

Powerful Polymer

Among the most dependable products for leveling concrete slabs, AP Lift 440, provides an exceptional DOT grade solution for these types of situations. This 4 lb. density, high-strength, hydro-insensitive structural polyurethane foam is perfect for lifting and supporting heavy concrete floors that have settled due to water infiltration.

Painless Procedure

An Alchemy-Spetec certified contractor lifted 5 slabs and fine-tuned 3 others that the mudjackers had unsuccessfully attempted with cement grout.  Overall, nearly 900,000 pounds of sunken slab were lifted with only twelve 100 gallon sets of 440; all in less than a week.

Rapid Result

The level of precision achieved with polymer foam was not only far greater than anything the mudjackers were able to deliver, but the rapid results allowed for the heavy seed sorting equipment to be installed on stable floors just in time for the fall harvest.  The floors are still perfectly level to this day.

Want more in-depth info on polyurethane concrete leveling?

Nowhere on earth are they building more railroad lines than in the People’s Republic of China. The most populous nation in the world is developing rapidly and with it comes a need for more and more freight and passenger rail - and the demand for higher and higher speeds. Unfortunately, these high speeds cannot be achieved on rail that is sinking and settling in various places, especially in tunnels. This slows down people and commerce and is also a concern for safety. The culprit is groundwater, soil consolidation, and in some cases poor compaction. This is the type of environment where AP Lift 475 has done some of its best work.

Powerful Polymer

AP Lift 475 is a two component, hydrophobic, structural lifting polymer designed for airport, highway, and railroad applications. It can be used to stabilize structures, fill voids, and lift slabs supporting tremendous loads. The real beauty of it is the ability to be traffic ready for a train or a jumbo jet in less than one hour. A few years ago, it was put to the test in tunnels in the mountains of China.

Painless Procedure

With rails sitting on double concrete slabs (the top slab was 1 meter thick, the bottom 30 cm) a plan was developed to bring the low spots back into tolerance by injecting AP Lift 475 underneath both slabs through extra-long injection packers.

Monitoring with laser levels, the low spots in the rail were lifted back to the original grade. AP Lift 475 performed as advertised. The railroad track was raised and supported, while at the same time the ground water was displaced, literally jetting out of relief holes as it sought a place to escape.

Rapid Result

Working in 4 hour windows where the rail traffic is shut down at night, crews lifted low spots in these tunnels quickly and efficiently.  At 5 AM equipment and personnel had to be clear of the tracks and 15 minutes later the trains would rumble through.  Vibration monitoring by railway engineers showed a smoother ride and the people and commerce of China were allowed to move once again at a frenetic pace.

Want More In-Depth Info on Concrete Leveling Polyjacking Products?

County inspectors found a depression in the road due to an underground sewer line that wasn’t sealed at a heavily trafficked roadway intersection in Orange County, Florida.  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.  In this particular case, there was a patch of asphalt 12’ x 25’ that was settling and officials feared a cave-in would occur.  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. It was going to be very difficult and inconvenient to dig up this roadway, fill the void, re-compact, and re-pave due to the high volume of traffic, the adjoining rail crossing, as well as several major utilities running through the area.  Not to mention that the area would have to be completely shut down to accommodate all of the equipment required for such a repair.

Powerful Polymer

Orange County approached us to see if we could come up with a powerful, painless and rapid solution for their maintenance crew using chemical grouting to fill the voids and stabilize the roadway. We devised a solution for them using the versatility of AP Fill 700 as both a permeation and void filling grout.

Painless Procedure

We advised their crew to lay out a grid on the settling asphalt area and set up injection points to drive pipes down to the 13’ depth where leaking had occurred and where the loose soil zone was located. They monitored the pipes while injecting material at a rate of 2 gallons per vertical foot through the open manhole to identify additional leaks that had been missed during the first point repair. As expected when foam was observed coming in through a leaking joint it quickly sealed off the leak at the same time it was stabilizing the soil.

Rapid Result

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.

Want in-depth info on soil stabilization products?

On top of a hill northeast of Chattanooga, Tennessee sits a clearwell that belongs to Eastside Utilities. Built in the 1940’s on a former Army post, this clearwell consists of twin 2-million gallon tanks used for treating surface water to turn it into drinking water. The problem was that less than half of the water coming into the clearwells was making it out the other side. Although this water treatment plant has undergone several upgrades in its 70+ year lifespan, the ground beneath it has been subject to settling and consolidation. The tanks had shifted slightly and in doing so, loosened some of the joints and the water stops contained within. Measurements indicated that the clearwells were losing 1,700 gallons per minute through various leaks; well over 2-million gallons per day. A short drive downhill from the property revealed various gullies and small creeks created by water running down the hillside.

Powerful Polymer

An Alchemy-Spetec certified installer was called in to utilize Spetec PUR GT500, an NSF /ANSI 61 approved product for contact with drinking water, to seal the leaks.  This single component polyurethane resin is designed to penetrate and seal off leaks in cracks, joints, and pipe penetrations.  As a hydrophilic polyurethane, it chases down water and gets into the microstructure of the concrete, forming a flexible seal and a tenacious bond with the wet concrete.

Painless Procedure

Due to the amount of water escaping, all of the joints around the perimeter walls were suspect as well as the roof support columns throughout each clearwell that penetrated through the floor.  The contractor drilled holes to intersect the leaking joints around the perimeter of the clearwell and along all interior joints.  Injection ports were installed and Spetec PUR GT500 was pumped into each one to create an injected membrane within the joints and beneath the clearwell.

Rapid Result

After three days of injection the work was done and the site was cleaned up.  Monitoring after the Spetec PUR GT500 was installed indicated that the leak had been reduced from 1,700 gallons per minute to 10 gallons per minute.  The small number of remaining leaks were attributed to the many vintage valves and fittings that are still present at the plant.

Want in-depth info on polyurethane leak seal injection?

In our continuous effort to make sure you have the technical knowledge to succeed, we’ll explain how to select the appropriate slab lifting polyurethane.

Use the Right Supplier

First and foremost, you want to be sure you’re working with the right supplier.  For niche work like polyurethane slab lifting, you need a company that specializes in polymer concrete repair materials.  Some larger polyurethane manufacturers make everything under the sun in addition to lifting foam, such as mattress foam, carpet padding foam, etc.  Your materials would be manufactured quarterly at most.  Technical support, if it exists, is unfocused and lacking in detailed expertise.  Don’t set yourself up for failure by going this route.

The right supplier will be a specialized polymer manufacturer with a laser-like focus on producing the best slab lifting foam possible.  Even better, they should offer dedicated tech support from professionals with field experience on actual slab lifting jobs.  Set yourself up for success with the absolute best supplier partner you can find.

If a Specification Exists, Read it!

If you’re working on a larger job involving an engineering firm, make sure you read the specs!  (If the Department of Transportation is involved, they will also have one available.)  For experienced contractors, this is just basic common sense obviously.

Foam for Filling Voids

An empty void underneath a slab needs to be filled with a lighter density foam that has an excellent expansion rate yet still ahs the structural strength for the application.

Different Foams for Different Lifting Jobs

The foam you choose for lifting will depend greatly on the size of the slab and the amount of weight it typically bears.

• Residential Jobs
  Driveways, walkways, garage floors and the like can usually be lifted with 3 lb density foam such as AP Lift 430.

• Common Commercial/Industrial Jobs
  Warehouse floors, concrete retail floors, larger concrete parking slabs and the like will require 4 lb density foam such as AP Lift 440.

• Maximum Weight Bearing Slabs
  Airport runways, railroad slabs, transformer pads, factory floors with heavy equipment, grain silo slabs and the like will require 4.75 density foam such as AP Lift 475.
  

Foam Designed for Wet Environments is Essential

At LEAST 90% of the time, water is the underlying cause of slab problems.  On most jobs, the soil will contain at least some infiltration.  So ALWAYS make sure your foam is designed for environments with moisture in the soil.  Many companies offer resins that will NOT work in wet environments or will require a lot more material to get the job done.  Why pay good money for a product that won’t work 90% of the time?  Every Alchemy-Spetec lifting foam is designed to work in wet environments.

NSF Approval is a Must

NSF approval is ESSENTIAL for doing work near waterfronts, food processing operations, water treatment plants, etc. 

This single designation ensures compliance with the Safe Water Drinking Act (SDWA) and guarantees peace of mind for in-the-field stakeholders on construction projects of almost any scope and size.

The SDWA gives the EPA latitude to impose criminal and civil penalties on industries not in compliance. In 2014 enforcement efforts policing clean water netted $163 million in penalties and fines, 155 combined years of incarceration for sentenced defendants, and $16 million in court-ordered project clean-ups.

Contractors and engineers must be able to confidently choose vendors whose products and services won’t become the source or cause of drinking water contamination.

Alchemy-Spetec is one of only TWO companies in the world with NSF approved lifting foam.

We’ve Got Your Back

If you’re still not sure what the right choice is for an upcoming job, then not to worry – we’re here for you!  Our staff has the expertise both in the lab and in the field.  We can help you make the right decision.  Just give us a call!

Want in-depth info on slab lifting polyurethane and procedures?

When it comes to custom slab lifting rigs of all shapes and sizes, Alchemy-Spetec is your one-stop shop!  Want to see a 16-foot V-Nose rig, stocked with top of the line slab lifting equipment and gear?  We'll give you a personal tour at World of Concrete 2019!  Drop by to see us at Booth # O40551 in the Silver Lots (same location we were in last year).

There will be a LOT to see and do at our booth this year: 

• See the Polybadger Lifting System in action. 
• Learn about preventative waterstop products. 
• Get in-depth instruction on using and cleaning the MixMaster Pro slab lifting gun. 
• View leak seal and curtain grouting displays. 
• Mix foam samples at our live mixing station. 
• Learn about the Deep Lift process. 

Respecting YOUR time is important to us.  So, in addition to the action-packed list above, you can schedule a one-on-one consultation with your regional rep for personalized product or equipment demos, tips and advice on building your business, etc.

Want a personlized one-on-one meeting at World of Concrete?