Foundation Leveling, Slab Jacking, Mud Jacking, Slab Raising

Structural Repair (Overview) Back to top

Settlement of buildings, homes, additions, and swimming pools is a serious problem that affects many owners in Florida. Because of Florida's geological history, the type of shallow surface soils that support our buildings are relatively loose sands, clays, and decaying organic material.

The most common visual indicators of foundation settlement are:

    1. Noticeable slopes in concrete floor slabs or floor framing.
    2. Cracks in exterior or interior walls, wider than 1/16".
    3. Misalignment of doors or windows (doors rubbing).
    4. Gaps below baseboards or above interior walls.
    5. Cracks in the exterior masonry.

The most common visual indicators of swimming pool settlement are:

    1. Uneven waterline compared with tile line.
    2. Cracks in pool tank, pool tile, and/or coping.
    3. Excessive sloping and/or cracking of pool deck.

While most homeowners are aware of problems with their home or swimming pool, they may not be aware that weak soil is the cause. The tendency is to treat the symptoms without addressing the underlying soil condition. Of course, this leads to remedies and patches that usually create a much more expensive repair later. Cracks should never be filled or patched until the underlying soil has been strengthened. There are multiple ways to strengthen soil and make repairs, however, not all repair procedures work on all soils. Owners should only consult companies with engineers on staff (such as us) when seeking repair options.

Foundation Underpinning Back to top

Underpinning is the process of modifying an existing foundation system by extending it to or into subsurface strata that is deeper and more stable than the near surface soil that sup- ports the existing foundation system. This is done to provide vertical support that is not present in the existing design. Methods of underpinning include the construction of footings, stem walls, driven piling or drilled piers.

Many of the houses that forensic engineers and repair contractors are asked to evaluate were constructed with foundations that are inadequate for the conditions existing on site. Because of the lack of suitable land, homes are often built on marginal land that has insufficient bearing capacity to support the substantial weight of a structure. As a result, underpinning is required to extend the foundation support to depths that provide greater bearing capacity and/or are less affected by climate, soil conditions and/or homeowner's actions. This underpinning, if properly designed and installed, provides the basis to lift the structure to a more acceptable elevation and provides vertical support to prevent the underpinned area from settling.

Foundation Underpinning

Pressure Grouting Back to top

The term “pressure grouting” is in widespread use, but it is frequently misused. Although it seems to describe a specific type of grouting, the term is not specific. It refers to a wide variety of procedures. All grouting is done under pressure, so it is kind of like saying, “wet water”. Permeation grouting is a more precise term for what is commonly referred to as pressure grouting.

Permeation grouting is the direct pressure injection of a fluid grout into the ground to fill the spaces between particles.

Injection methods are tailored specifically to a project. Some jobs are well suited to drill rigs and high-rate batch plants; other jobs are better suited to hand drills and small metering pumps. Sleeve-port pipes and down hole packers are often used to isolate particular zones in a formation. The choice of materials offer hundreds of options, ranging from cement slurries to specially designed chemical solutions.

All these options provide the project designer with a wide range of alternatives. Any effective grouting program requires a thorough evaluation of these options. The challenge is to find the best combination of methods and materials to achieve all technical objectives, while accommodating other factors such as existing ground properties, cost, and accessibility.

Pressure grouting is the process of raising sunken or deformed foundations by the use of hydraulic pressure, and then filling in the void created with concrete grout. Pressure grouting is generally used for large voids beneath the foundation surface.

The first step in pressure grouting is to determine the locations of the desired holes to be drilled that will best stabilize the foundation. Once the desired location for the holes has been determined, the drilling is done. Concrete grout is then pumped into the holes at high pressure until the concrete comes into contact with the existing foundation. While the concrete is pumped into the drilled holes, the hydraulic lifts maintain an even surface. As soon as the void beneath the foundation surface has been filled properly, the holes are refilled.

Mudjacking/Slabjacking Back to top

Mudjacking

Mudjacking is the process of pumping a water, sand and cement mixture under a concrete slab in order to lift it. This mixture is called slurry. The exact ingredients vary from company to company, and from job to job. Mudjacking can be the solution to many homeowners’ concrete problems, including foundation settling, crumbling curbs and repairing falling sidewalks. It may also be called concrete leveling, pressure grouting or slabjacking.

Slabjacking

If your concrete is sinking, there is a very good possibility that the concrete slab was installed on poorly compacted fill dirt. Sub-surface erosion and shrinking soils are also possibilities.

You are fortunate enough to have a slabjacker in your area, you will not have to replace the concrete. Certified Structure can float a slab back to its original position by pumping a mixture of sand, cement, fly ash, and other additives beneath your slab.

We simply drill strategically placed holes into the slab. Using a portable pump and flexible hoses, We fill these holes with the special mixture. Lifting a slab using this method can often be accomplished in a few hours.

Slab Jacking

Piling/Helical Piling/Pin Piling Back to top

HELICAL PILES & ANCHORS

CHANCE® helical piles and helical anchors have found increasingly widespread use within the structural and geotechnical engineering industries. The increased use is a direct result of the versatility and cost-effectiveness of the helical system. The ability to be utilized in both tension and compression applications make the pre-engineered system an attractive alternative to the foundation stabilization and earth retention sectors of the construction industry.

The helical system is segmented with helical bearing plates welded to a central steel shaft. Load is transferred from the structure through the shaft to the soil through the bearing plates. Central steel shafts are available in either Type SS (Square Shaft) series or Type RS (Round Shaft) series. SS-RS combinations are available when conditions require a deep bearing strata with an increased need for lateral stability.

Segments or sections are joined with bolted couplings. Installation depth is limited only by soil density and practicality based on economics. A helical bearing plate or helix is one pitch of a screw thread. All helices, regardless of their diameter, have a standard 3" pitch. Being a true helical shape, the helices do not auger into the soil but rather screw into it with minimal soil disturbance. Helical plates are spaced at distances far enough apart that they function independently of each other as individual bearing elements; consequently, the capacity of a particular helix on a helical pile or anchor shaft is not influenced by the helix above or below it.

Swimming Pool Repair Back to top

Most well-built and well-maintained swimming pools will last for years. But age and neglect can wear down a swimming pool and deprive it of the sparkling luster that once made it an inviting place to swim.

Even a carefully maintained swimming pool can show evidence of its age, decks can crack due to earth movements, the pool surface can change color, and the support system can break down. When the swimming pool has suffered through a period of neglect, these small problems turn into major repair jobs.

Cracks can be found in practically all concrete foundations. The various causes include improper concrete mix (high water content), rapid concrete curing, improper expansion control joints, premature removal of concrete forms (2 days instead of 7), compressible soil, premature backfilling, improper compaction of fill soil, expansive clay soils, uneven moisture around the foundation, plumbing leaks, poor drainage, and hydrostatic water pressure.

All structures settle. Because of variations in soil properties, not every point on a foundation settles uniformly, which causes cracking doorframes and cracking cement walls, basement walls, sea walls and swimming pools. Good construction prevents differential settlement and minimizes the overall settlement.

Over time, even minor cracks can grow larger and cause big headaches, such as loss of structural integrity. Repair cracks exposed to moisture as quickly as possible to avoid more extensive damage.

Swimming Pool Pressure Grouting Back to top

Allowing some problems to go unchecked for long periods of time can cause the problems to grow into larger, more costly issues down the road.

Swimming pools can develop cracks in the concrete that lies beneath the plaster finish, due to settling, ground shifting or erosion. Simple hairline cracks in the finish may not involve a leak and can, usually, be easily repaired. However, a crack that is structural in nature and is under stress cannot be simply glued in place or plastered over, as the forces involved will continue to pull the crack apart. Such cracks must be stabilized in order to prevent the crack from widening and causing ongoing leak problems.

Swimming Pool Mudjacking/Slabjacking Back to top

If your Pool Deck is sinking, there is a very good possibility that the concrete slab was installed on poorly compacted fill dirt. Sub-surface erosion and shrinking soils are also possibilities.

You are fortunate enough to have a slabjacker in your area, you will not have to replace the Pool Deck. Certified Structure can raise a Pool Deck back to its original position by pumping a mixture of sand, cement, fly ash, and other additives beneath your slab.

We simply drill strategically placed holes into the slab. Using a portable pump and flexible hoses, We fill these holes with the special mixture. Lifting a slab using this method can often be accomplished in a few hours.

Swimming Pool Pin Piling Back to top

CHANCE® helical piles and helical anchors have found increasingly widespread use within the structural and geotechnical engineering industries. The increased use is a direct result of the versatility and cost-effectiveness of the helical system. The ability to be utilized in both tension and compression applications make the pre-engineered system an attractive alternative to the foundation stabilization and earth retention sectors of the construction industry.

The helical system is segmented with helical bearing plates welded to a central steel shaft. Load is transferred from the structure through the shaft to the soil through the bearing plates. Central steel shafts are available in either Type SS (Square Shaft) series or Type RS (Round Shaft) series. SS-RS combinations are available when conditions require a deep bearing strata with an increased need for lateral stability.

Segments or sections are joined with bolted couplings. Installation depth is limited only by soil density and practicality based on economics. A helical bearing plate or helix is one pitch of a screw thread. All helices, regardless of their diameter, have a standard 3" pitch. Being a true helical shape, the helices do not auger into the soil but rather screw into it with minimal soil disturbance. Helical plates are spaced at distances far enough apart that they function independently of each other as individual bearing elements; consequently, the capacity of a particular helix on a helical pile or anchor shaft is not influenced by the helix above or below it.

Pin Piling

Commercial Building Repair Back to top

Commercial building foundation repairs are services that Certified Structure & Foundation Inc. provides to businesses throughout Florida. Commercial buildings can suffer minor to very extensive foundation and slab distress. Soil related movement and heavy equipment is often a contributor to distress of commercial buildings.

Certified Structure & Foundation Inc. can assist you in determining the causes related to your building’s distress. We can also assist you and/or your tenants in repair to your commercial building's foundation.

Common Repairs Include:

• Epoxy Injection
• Floor Leveling
• Slab Replacement
• Posts Repairs
• Stemwall Repair
• Retrofitting
• Underpinning
• Pipe Piles
• Hellelical Piers
• Stabilization

Services Overview:

Certified Structure & Foundation Inc. carries the proper licenses and insurance coverage to provide professional structural repairs to your multi-family residential property.

We provide a FREE site visit (inspection) to consult with you regarding your repair strategy.

Articles Back to top

The following article appeared in the Saturday, November 24, 2007 edition of Florida Today in the Space Coast section.

Do You Have That Sinking Feeling?

By David Bryant P.E.
Certified Structure and Foundation, Inc.

Settlement of homes, additions, swimming pools, and porches is a serious problem that affects many homeowners in Florida. The obvious signs of settlement are cracking of your walls, doors or windows not closing properly, and sloping of your floor slab or outside corners of your home. If there are cracks in your pool or the waterline is uneven then you may have abnormal settlement.

Most contactors are not engineers and do not have the expertise to properly repair buildings with settlement problems. Therefore, before you do anything, contact CERTIFIED STRUCTURE AND FOUNDATION, INC. for a free soil test and engineering analysis of your problem. As a structural engineer with over 30 years of experience solving settlement problems, I can help you decide how to repair your home properly and economically.

Never try a "do it yourself" fix of your settlement problem! Digging around or below your foundation and pouring concrete is a bad idea. The weak soil causing your problem is typically deeper and the additional weight (of the concrete you poured) will only accelerate the settlement.
If you do have settlement problems at your home, business, or the condominium where you live, we offer FREE inspections, FREE soil testing, and FREE engineering opinions covering a full range of repair options. The most common and economical repair technique is "pressure grouting" which consists of injecting cement grout into the weak soils beneath your foundation, usually beginning at a depth of 10 feet. If your home has experienced excessive settlement, it may require "underpinning" of the foundations using piers or piling to transfer the foundation loads to deeper, more stable soils. In most cases, your foundation can be lifted back to its original elevation.

Of course, you want the most economical repair solution, therefore, you would not want to underpin your home with piling capable of supporting a five story building when pressure grouting will solve your problem for a fraction of the cost. To stabilize minor settlement of one corner of your home should cost approximately $3,200 dollars for labor and materials. To underpin and lift one corner with excessive settlement could cost much more. That is why it is very important to strengthen the weak soil as soon as you notice a problem.
Contact our office for your free inspection and free soil test. We will perform a thorough investigation of your settlement problem and test the soil to a minimum depth of eight feet. At that point, we will be able to make engineering recommendations, which usually include several options for repair and their associated costs.

I would advise anyone with a settlement problem to "Do your homework" and get a qualified engineering opinion before you spend money to fix your building. We are the best in the business and we offer the best warranty. See our ad below and call us at 321-242-1003 or 800-LIFT-YOU. We also offer a wide range of engineering and construction services that are beyond the scope of this article.

David Bryant P.E. is a registered structural engineer (FL Reg. #038154) and general contractor (License #CGCA25869) in the State of Florida and owns & operates Certified Structure and Foundation, Inc. Over the past 30 years, he has designed, built, and repaired almost every kind of structure imaginable from single family homes and high-rise condominiums to launch pads for NASA.