Can you successfully repair foundations?

With today’s technology and trained experts, there are a number of very successful solutions to the problem of sunken concrete that involve little or no disruption to normal living or business routine. The two most common methods of this type of repair are slabjacking and hydraulic jacking (also known as piering). 


Slabjacking 


In a slabjacking operation, grout is pumped beneath a slab or beam to produce a lifting force that restores the member to its original elevation. In piering, steel posts are driven through unstable soil and hydraulic jacks are used to raise or stabilize concrete slabs affected by changes in the underlying soil. The repair method used depends on the type of distress being treated. Slabjacking is an alternative to replacing sunken or uneven concrete, restoring sunken concrete slabs to their original grade and is performed on cracked and sunken concrete slabs such as driveways, steps and sidewalks, concrete pavement floors and other slab on grade surfaces. Performed properly, slabjacking can not only bring the concrete up to grade, it can also eliminate costly and irritating water problems by filling hidden cavities under the concrete and diverting water away from the foundation.

Piling or piering

Piling or piering is the technique of driving steel pipe pilings to remedy failing building foundations and to correct foundation settlement. Push piers consist of sections of galvanized or epoxy-coated steel pipe that are driven into the soil with a hydraulic ram. Helical piers use screw piles with steel shafts. The lead section, with one or more helixes attached, provides the needed bearing capacity. The piers are screwed into the ground with a hydraulic torque motor.

With either system, one or more steel piers are driven to rock or a suitable soil bearing layer and are connected to the foundation through a metal head assembly. Once a suitable bearing stratum is reached, each pile is tested to a force greater than required to support the structure. Hydraulic jacks attach to the embedded steel piers and are used to raise the foundation back to its original elevation. Once the structure is restored to the desired elevation the piles are affixed (bolted or welded) to wall brackets, locking the new elevation of the structure.

Piers also offer an affordable solution for decks, porches, patios, hot tubs as well as pre-fab buildings. Piling or piering is the technique of driving steel pipe pilings to remedy failing building foundations and to correct foundation settlement. Push piers consist of sections of galvanized or epoxy-coated steel pipe that are driven into the soil with a hydraulic ram. Helical piers use screw piles with steel shafts. The lead section, with one or more helixes attached, provides the needed bearing capacity. The piers are screwed into the ground with a hydraulic torque motor.

What does it cost?

The average foundation repair cost is difficult to quantify because of all the variables that can affect each home or structure, according to DeWayne Snider (Yellow Hat Home Inspector and Architect). He says that the typical foundation repair using hydraulic piering runs about $10,000 to $14,000 for an average home ($1,340 per pile at 6- to 8-foot spacing). A repair of a simple crack in a poured concrete wall is usually in the range of $800 to $1,500 per crack. For slabjacking work, the typical cost of concrete removal and replacement on a porch or sidewalk is $150 per hole.

In addition to the complexity and scope of the problem, other variables that can add to the cost of foundation repairs include:

1. Hiring a structural engineer to assess the damage (typically $300 to $1,500).
2. Getting a soils report prepared by a geotechnical engineer, if needed (about $500 to $3,000).
3. Obtaining a local building permit, if required ($75 to $150).

Dealing with hidden obstacles in the ground, such as old repair methods, extra-deep footings, or tree roots may add an average of $1,000 to $2,500 to the overall cost. Although the total cost for foundation repairs can be substantial, Snider notes that your home is often your biggest investment and these repairs when properly done by a reputable contractor, can be essential to protecting your equity and keeping your property marketable.

Important tips when hiring a contractor

Foundation work is definitely not a do-it-yourself project, so it makes good sense to get at least three licensed contractors to give you a detailed proposal along with an assessment of your issues. The average inspection takes about two hours. Ron Davidson of Ram Jack Systems also offers the following advice and precautionary measures:

"Educate yourself on foundation repair methods and ask a lot of questions. Don't make your final decision based on advertising and cheap prices. If it sounds too good to be true, it probably is.

Don't do business with a contractor that does not have their foundation repair methods evaluated by ICC-ES (International Code Council Evaluation Services). This nonprofit organization ensures that building products meet code compliance.

In most areas of the country, a reputable contractor will have a clause for the depth of the hydraulic piling (typically 20 to 30 feet). Beyond that depth, there is usually an additional charge, ranging from $20 to $30 per foot. If a contractor has no depth clause, be cautious. It's unlikely that the contractor would continue to operate at a loss, and would instead just stop at the depth that would guarantee a profit.

Some foundation repair projects require removal of landscaping in the areas of the work, and the contractor typically won't guarantee that a bush or shrub will survive after removal and replacement."

Warranties or guarantees

Warranties or guarantees for foundation repair work are very important, so pay close attention to their terms. Remember that a warranty is only as good as the company that backs it. Look for a national company that can offer a warranty trust. This means that if the company goes out of business, there is a plan in place to provide follow-up service, if needed.