This day and age homeowners have many choices when faced with a structural foundation problem. The choices include helical piles, push piers, helical tie-back anchors and plate anchors. Each one of these solutions should only be implemented under the supervision of a qualified engineer and foundation repair contractor. Foundation repair is not a do-it-yourself home improvement project. Intimate knowledge of structures, soils and available products are necessary requirements before repair design can be implemented.
Homeowners must educate themselves to keep ignorant or slick talking salespeople from selling them a bill of goods. Many times the salesman does not represent all of the products that your structure may need to completely solve your foundation repair needs. If he only does waterproofing he will, at best, only slow down or prevent further problems. If he is only a pier guy, he may not have the knowledge of what caused the problem (i. e. water). This is why contacting a qualified foundation engineer is a form of checks and balances to allow for the best possible solution.
Foundation engineers will give you a written assessment of your structure including a recommended procedure to solve your homes issues. This evaluation is conducted on site and usually takes over an hour to complete. The written assessment involves an examination of the interior and exterior of the home, interior floor elevations, load calculations and recommendations on repair methods. The written report should include an imprint of his seal with the date and signature across the seal. Many times the engineer will recommend a foundation repair specialist, that he has worked with before, in his report.
You first must understand what different foundation repair methods can and cannot do to determine if they are the correct method of repair for your home. There is no such thing as one size fits all in foundation repair. Each has their place and their benefits, so make sure that the tool that you pick is the correct one for your job.
Resistance piers, also known as push piers, steel piers and Micropiles. This type of pier is an end-bearing pier that does not rely upon, nor requires, skin friction to produce support. Each pier is field load tested after it is installed. The piers are able to develop a factor of safety because the piers are installed and load tested individually using the weight of the structure as the reaction force. Unlimited lifting capability is offered in continuous lift systems. These lifts should only be performed with a manifolded hydraulic system using single or double acting hydraulic cylinders.
Steel push piers are best suited to any structural problem that requires a large lift. No other system is as suited for these large lifts. Due to the fact that these resistance piers are an end bearing pier, thus developing their support from solid contact on a load bearing stratum. Continuous lift type steel piers are the best of the steel resistance piers due to the fact that they can support and lift a structure to unlimited heights.
Helical piers are an ideal choice when you are supporting or lifting a light structure. They are the ideal choice for light structures due to the fact that they do not need the structures weight to advance into the soil. Helical anchors are screwed in the soil with a hydraulic torque motor as opposed to be pressed into the soil like steel push piers. Like the resistance piers you should only lift the structure with a manifolded hydraulic system using single or double acting hydraulic cylinders.
Helical piers consist of a shaft fabricated from either solid square steel bar or tubular steel. Welded to the shaft are one or more helical plates. Typically the plate diameters increase from the bottom of the shaft upward and vary in thickness from 3/8" to ½". The torque required to install the anchor correlates to their capacity. When used to support or lift light weight structures, helical piers are an excellent choice, due to their many benefits. These benefits include the ability to be quickly installed with little or no disturbance to the site and soil removal is unnecessary, they don't require a reaction force and are extremely versatile in their applications.
While steel resistance piers and helical torque anchors are excellent choices for supporting sinking foundation elements, helical tie-back anchors and plate anchors are just as able to support or straighten concrete or block walls. When a basement wall or retaining wall bows inward one must resist this inward movement to maintain the integrity of the structure. If such a system is not installed catastrophic consequences are forthcoming.
Tie-back anchors and plate anchors resist the lateral soil and water forces exerted on basement and retaining walls. While both systems have different advantages they both provide the same function. They use the surrounding stable soils to resist the pressures of unstable consolidating soils near the foundation.
While one or more of these systems my be needed to fix your foundation problem, understanding each method is the key to determining the solution that best fits your situation. The hiring of a foundation engineer is the most effective method of making this determination.