Alchatek Blog

A home or commercial building is only as good as the foundation it’s built on. And regardless of how well-constructed a structure may be, most foundations settle. That’s just a fact of life. Shifting soil compaction and many other environmental conditions that tend to cause settling, however, should ideally be stabilized before significant structural damage is done.

One or two minor hairline or shrinkage cracks shouldn’t necessarily send off any warning bells – though both merit monitoring. But multiple or widening cracks indicate more serious problems and may lead to additional damage. For the property owner, this can disrupt business, displace occupancy, and cause a domino-effect of infrastructure woes serious enough to break the bank. Or worse. Litigation can result if preventative action isn’t taken before loss or injuries occur.

These factors alone make acting sooner rather than later imperative. Stabilization and lifting are key solutions to consider in cases of foundation or slab distress. How can you know for sure if slab lifting or soil stabilization is needed? Watch for these five warning signs:

Bulging or Cracked Floors

It’s estimated that 60 percent of homes built on expansive soils result in shifting and heaving in all or even just part of the foundation. One can’t-miss sign of distress caused by wobbly soil compaction is buckling and bulging wood floors or evidence of cracking concrete in other types of flooring.

Cracked Walls

When soil moisture levels are all over the map, you can be sure that problems will ensue. Poor drainage, soil decomposition, naturally occurring conditions, nearby sewer line damage, underground aquifers – all can play a role in fluctuating soil moisture levels that lead to foundational settling. Cracked sheetrock or concrete walls are a warning sign that trouble is brewing underneath the surface.

Sticking Doors

When doors suddenly start sticking or won’t easily open or close, it’s a sign that either moisture levels are causing the door to swell or something in the structural frame has shifted. And that something might very well be the foundation.

Displaced Moldings

Look up toward the ceiling or down at the floor for moldings that may have gone wonky, jutting this way or that.

Leaning Trees, Fence Posts, Etc.

It’s hard not to notice a tree, fencepost, mailbox, or flagpole that is leaning like the Tower of Pisa. If you don't associate this abnormality with foundational distress, you should. It can be a sign of sinkholes – the kind that gape and maw without warning. If the site you're evaluating is in what is known as karst terrain, which about one-fifth of the nation is, it's susceptible to sinkholes. Likewise if there are abandoned coal or other mines, sewer construction or groundwater pumping nearby. All are signs that further investigation may be needed, pronto.

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Welcome to the 3rd and final part of my blog post series “Sealing Leaks on Remote Job Sites”. In Part 1 and Part 2 of this series, I described a remote leak seal job I assisted a customer with and the unique preparations it required. So to pick up the story where I left off - there we were, in the jungle, about a mile from our trucks. Of course we were doing our best to deal with the August heat and humidity. At least we had poison ivy, ticks, and yellow jackets to keep us company as we tackled these pipe penetration leaks on the aerial manholes.

As I mentioned, we removed as much of the old mortar from the pipe penetrations as we could. We also drilled our port holes at this time, about 5 inches apart and all the way around the pipe penetration. The port holes were drilled at a 45º angle, and located so that the injected resin would hit the pipe about midway through the penetration. Then we flushed out the areas and port holes with clean water.

Now it was time to seal it. We soaked oakum in the polyurethane and then gave it a quick dip in a bucket of water to get it activated. Then we packed it into the pipe penetration as deep as we could get and all the way around the pipe completely to form a back seal. Then we did it again forming another seal all the way around the pipe penetration but this time towards the outside wall of the manhole. Finally we injected the urethane into the ports working our way from the bottom to the top, completely around the pipe penetration.

For this application, AP Seal 500 was the right choice. It reacts when contacted by water, it's flexible, and it bonds tenaciously to concrete. Plus, its low viscosity allows it to get into tight cracks and voids to seal off leaks. If there is water present in the cracks, it can be injected straight. We actually injected it with water using a two chambered cartridge and static mixer. One chamber held the resin and the other was filled with water just prior to injecting. The reason we did this was because we were working during the middle of the day when sewer flow was the lowest. There was no leaking water present in the penetrations so we had to provide our own. Injecting with the water provided the “kick” to make the urethane foam expand and form an excellent seal between the front and back oakum gaskets we created.

Although it was not in the contract, we couldn't ignore the other small leaks through the manhole walls. Plus we wanted to help the county in return for their clearing the footpath to the manholes. These particular leaks were below the pipe penetrations and were constantly seeping sewage water. There were literally hundreds of yellow jackets swarming on the wet manhole face but they didn't bother us. To repair these leaks we drilled port holes that would intersect the cracks at an angle. As always, we flushed out the holes with clean water. As an experiment, we only put in a couple ports and then started injecting the same polyurethane; this time without additional water as there was already water present in the cracks. Sure enough, the low viscosity resin traveled throughout the cracks as it was injected and sealed off the areas where water was working its way through.

When we were finished, the manholes were completely dried out and there was no longer sewage leaking into the sandy soils beside the creek. It always feels good to get a job done when there's the added benefit of doing something to protect the environment. It also feels good when a project goes smoothly because you took the extra time to visualize it, plan the work, and work the plan.

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In Part 1 of this series, I laid out the challenges my customer's crew faced repairing pipe penetrations on aerial manholes in a very remote area. The repairs aren't that hard, but when you have to carry all of your materials and gear across creeks and down gullies, you have to work smart.

Previously, I indicated how we took the time to do a thorough site evaluation. Then we created a plan and a master list of what we would need; knowing we would have to carry everything in and out. We decided to repair the penetrations with a combination of polyurethane soaked oakum as a packing material and a low viscosity hydrophilic polyurethane that we would inject.

These particular pipe penetrations had originally been sealed with mortar and the manholes were of brick construction. Since they were also quite old, the leaks were not very hard to find. In fact there were gaps up to one inch in width between some of the pipes and the penetration holes. The mortar had just crumbled away. In addition to the penetration leaks, there were also several leaks through the walls of the manholes. A skim coat of mortar had been applied to the outside surface, covering the bricks. But now waste water and sewage was finding its way through the many brick seams and joints, and the crumbling mortar too.

I'll spare you some of the things we used that are common to all of our jobs; items such as buckets, mechanical ports, drill bits, gloves, safety glasses, etc. Items of note that did come in handy on this remote project were as follows:

1. Plastic sheeting to cover our gear when it rained and ponchos for ourselves.
2. A hand powered, 2-component cartridge gun. We were prepared to use a small CO² tank to power our pneumatic gun but it turns out we did not need much pressure to inject the resin.
3. Battery powered Ridgid brand hammer drill with 3 extra batteries. It took one battery to drill port holes 360º around each 22” diameter penetration. During lunch we would take the batteries to the truck and recharge them with our generator.
4. We brought a light weight plastic chemical sprayer. We were able to fill it with water from the creek and it generated enough pressure to flush our drill holes and the areas around the penetrations where we dug out the old mortar.
5. Light weight dry oakum. This was great for sealing the large gaps. Dry oakum can be soaked in polyurethane, packed into joints and cracks, and activated with water. It will swell up and become like a flexible gasket.
6. Bug spray and a sense of humor.

In my next and final installment on this subject, I'll go into detail about how we actually completed the repair and saved the planet. To wrap up this one, I would just say that it pays to think things through and be creative. There are usually several ways to get the job done; in our case we had to get the job done without exhausting ourselves getting there and back. We brought lightweight cartridges and oakum, battery powered hammer drills, and simple plastic sheeting to protect from the elements. These things took the place of pumps, compressors, electrical power, and shelter.

There's one last thing I recommend looking in to: Even though this was a job that could only be accomplished on foot, the owner of the pipeline was the county and they have to maintain a path so they can walk the line, make repairs, and cut up trees that fall across the pipes connecting the manholes. For this job we worked hand in hand with the county, walked the line with them, and got them to send in their crew to clear out the path anew for us. Our repairs repaid them for their free help.

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Hopefully these tips on overcoming obstacles on remote job sites will be of assistance on your next out-of-the-way project. At one point I had the opportunity to advise a customer who was repairing pipe penetrations of aerial manholes along a drainage basin in SW Atlanta. Aerial manholes are typically found in low spots next to creeks and rivers. They are usually connected by steel or ductile iron sewer pipes that are above ground and thus, so are the penetrations.

The conditions of the job site were unique as there was no access to the individual manholes except by foot. This particular project covered a winding 1-1/2 miles through ravines and involved several crossings of the stream. The goal was to seal the 18” and 22” pipe penetrations that were leaking raw sewage down the faces of the manholes located along the creek. In this report I will let you know how we got started in preparation for the unique set of challenges this project presented.

First of all, a thorough evaluation of a remote job site must be undertaken. This should be done prior to submitting a bid, but it should also be done again with an extra set of eyes prior to commencing the work. Then create a plan and a master list of what you will need:

1. Consider all of the possibilities of how to mobilize; where can you set up the nearest base camp for your trucks and supplies.
2. What tools or alternative tools can be used to get the job done; realize there are certain conveniences you're not going to have, like generators and air compressors, and find alternative methods.
3. Select the right Leak Seal materials to get the job done such as AP Seal 500, AP Fill 700 and activated oakum.
4. Prepare a good safety plan. We experienced rugged terrain, snakes, bees, ticks, extreme heat, downpours, and lightning. Think about how to protect your people, your materials, and your gear. Make sure to have first aid and hydration available on site and at the base camp.
5. Have a communication plan – make sure you have reception between the job site and the base camp. If cell phones don't work then bring walkie talkies. Have someone at the base camp to watch gear, to get supplies when necessary, and to be available for help in case of an emergency.
6. Be prepared to clean up your job site with respect for the environment. If you haul it in, be ready to haul it out.
7. Last of all, choose the right people for your crew. Think carefully, because these kinds of jobs are not for timid or easily discouraged personality types.

In my next post I will go into detail on the procedures and tools we used to stop the leaks through a combination of polyurethane injection and activated oakum.

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Water leaking through concrete can lead to structural failures, sinkholes, and other costly types of property damage. For property owners, it is important to be aware of potential problem areas in your facility, factory, or residence. For concrete restoration and waterproofing contractors, it is important for your business to know where to look for leak sealing opportunities.

So where are the areas that contractors and property owners need to be looking? Here we have broken it down into two broad categories: Commercial / Industrial / Municipal and then of course, Residential.

Commercial / Industrial / Municipal

• Tanks: Water and Wastewater Treatment Plants, Aquariums
• Infrastructure: Concrete Pipe, Manholes, Pipe Penetrations, Lift Stations, Pumps Stations, Utility Vaults
• Industrial Plants: Machinery Pits, Containment Structures, Retaining Walls, Slab Joints
• Tunnels: Tunnel Segments, Retaining Walls, Headwalls and Wing Walls
• Commercial: Floors, Parking Structures, Elevator Pits, Basements
• Specialized arenas for sealing leaks in Mines, Dams, and Power Plants.

Residential

• Single Family: Basements, Foundation Walls, Swimming Pools, Fountains, Seawalls, Retaining Walls
• Multi Family: Elevator Pits, Parking Garages, Seawalls, Pools, Basements
• Farms: Silos and Tanks, Earthen Dams, Manmade Ponds

Alchemy-Spetec manufactures an effective range of polyurethanes designed to seal leaks for all of the above issues. We also strive to continually educate the market. 

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Leaking concrete structures can be permanently repaired using a water-activated flexible foam. Pressure injection of these liquid resins forces the material into leaking cracks, joints, and other defects where the resin rapidly reacts with water to form a flexible, water tight seal.

From hairline cracks to gushing leaks, virtually any of these defects can be repaired with our leak seal resins. Take a look at this polyurethane leak seal demo video.... 

When the residue of plants or animals is converted into soil, the process is known as decomposition. Bacteria, fungi, and worms break down this residue, taking nutrients from them and leaving the remaining portion. Organic molecules are broken down into simpler inorganic molecules. This biological process changes the makeup of the soil and can therefore lead to soil instability.

What are the causes of decomposition?

When soil has a high concentration of organic materials, the soil will naturally begin to decompose. Throughout this process of decomposition, the mass and form of these organic materials will change. Up to 90 percent of organic material will actually disappear over the course of the decomposition process, which means the mass of the soil will decrease substantially, reducing the quantity of available soil. The causes of decomposition can be broken into two main groups: manmade and natural. Trash pits or buried construction debris can cause manmade decomposition, while tree stumps and peat content can cause natural decomposition. 

What are signs of decomposition?

Sinkholes, unstable soil, and low spots are all indications of soil decomposition. When soil begins to decompose and shift, it can affect the structural stability of a building, compromising the integrity of foundations and manmade structures. 

How can decomposition be addressed?

In some cases, it is possible to dig up the cause of decomposition. For example, it might be possible to extricate a trash pit or old construction debris from the soil. However, in some cases this simply isn’t feasible. You can’t easily extricate a trash pit after you have already built on top of it. If removal isn’t an option, the best solution is to envelope the area with a high concentration of organic material using expansive polyurethane. This process is known as encapsulation, and it essentially works to compact the area and reduce the amount of oxygen and water that can get to it, thereby helping to slow decomposition.

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What is freezing and thawing?

As the name suggests, freezing and thawing refers to a natural phenomena in which soil freezes in cold weather and then thaws out again once the temperature warms up. Freezing and thawing in northern climates is good news for farmers, as it helps to loosen up the soil and reduce compaction, which makes it easier for crop roots to grow. However, for construction engineers and contractors, freezing and thawing can prove to be incredibly problematic, especially if they are building on fine-grained soils with silt or clay factions, which are more prone to freezing and thawing.

What are the problems associated with freezing and thawing?

Essentially, freezing and thawing cycles accelerate soil instability. Soil with pores containing small particles of frozen water, is known as permafrost. Building on permafrost is fine, as long as the soil stays frozen, but things become problematic once the permafrost begins to thaw. Freezing and thawing of permafrost causes soil to become soft and less compact. Subsequently, this causes structures, such as roadways, railways, foundations, and pipeline supports, to sink. Obviously, this can cause major headaches.

How can the problem of freezing and thawing be mitigated?

Structural polyurethane such as AP Lift 475 can be used to raise settled structures and compact the ground. In addition, permeation grout such as AP Soil 600 is now being looked at as an option to displace water particles in the soil pores. Depending on the soil type, this could prevent frost heave, resulting in a stronger, more consistent base to build on.

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Many types of infrastructure, including roads, bridges, buildings, etc., depend on compacted soil in order to stay in place. Therefore, in order for these structures to last, a specific degree of compaction must be achieved. When soil does not adequately compact, the problem is known as poor compaction, and that can lead to more serious issues. Concrete repair contractors always need to be on the lookout for signs of poor compaction which include settling slabs, cracking foundations, and dips in roadways and railroads.

What causes poor soil compaction?

There are a variety of causes of poor soil compaction. However, much of it boils down to soil texture and soil properties. Some soils are more prone to compaction than others. Excess soil salt content, high clay fraction soils, low pH soils, and soils with high water content tend to compact less favorably. It should also be noted that decisions made by construction contractors and their teams can also influence soil compaction. For example, failure to select proper compaction equipment or compaction materials can contribute to poor compaction. Furthermore, some areas are more prone to poor compaction than others, such as portions of soil set against a foundation.

How can poor soil compaction be corrected?

Luckily, poor compaction can be corrected. The solution is to strengthen the soil to the point that it is properly compacted. As mentioned in the previous post, AP Soil 600, AP Lift 475 and AP Fill 700 are a few products that may be appropriate. Contact Alchemy-Spetec for expert advice at 404-618-0438 if you are currently facing a soil stabilization issue.

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What is erosion?

In geological terms, erosion can be defined as exogenic process that moves a portion of the earth’s crust from one location to another. Exogenic process refers to a range of different processes, including water flow, wind, and even human action, that move dirt, soil, rock, etc. They are called exogenic processes because they originate outside of the earth’s crust, or externally. In more practical terms, erosion can best be described as the way in which the earth is worn away by water, wind, or ice. So when a river carves a canyon out of stone (such as when the Colorado River carved out the Grand Canyon in Arizona over the course of thousands of years), that is an example of erosion. The formation of sand dunes by the wind moving across the desert is also an example of erosion, as are changes in rocks along a shoreline due to the constant thrashing of waves. 

Why does erosion cause unstable soil?

You’ve probably heard that erosion is dangerous because it causes unstable soil. It is important to remember that consequences of erosion can potentially be dramatic, causing landslides and structural damage. After investing money in the construction of a building, the last thing you want is for unstable soil to put the whole project at risk. 

How can erosion be repaired?

Voids can be filled, soil consolidated, and water migration halted by permeating the soil with one of the ultra low viscosity polymer resins in our AP Soil series of resins. Once the bearing capacity of the soil has been increased with this process, then the structure can be lifted if necessary. For example, AP Soil 600 is a one component resin that requires no catalyst. This resin encapsulates and strengthens loose soil, is water tight, and environmentally friendly. Other AP products used in soil stabilization/void fill include AP Lift 475 and AP Fill 700.

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