There are many types of foundation repair for residential structures. Common foundation repairs refer often extend beyond beyond basic work to correct leaks, cracks, and curing a termite infestation. Advanced foundation repair is a common requirement.
The difference between basic and advance foundation repairs is best understood with the example of surface cracks in the basement. If after repeated crack repairing and sealing, the basement continues to show signs of gradual weathering, it poses the risk of permanent destabilization. In that case, advanced foundation repair is required.
Advance foundation repair includes using specific supplies that require careful handling and carry an above average cost. Some of the most common advanced foundation repair methods are explained below.
Advanced Foundation Repair Using Concrete Piers
More common in larger homes, this method is mostly seen in commercial buildings. The use of concrete piers is indicated when the basement is showing extensive signs of damage. Concrete piers are needed when the basement can no longer support the weight of the overlying structure and must have additional support. Symptoms pointing towards the need for additional support include excessive cracking along the basement walls and development of an undulating basement floor due to increasing compression forces.
This support is provided by inserting concrete piers. The piers are essentially concrete columns created by pouring concrete into big holes drilled under and around the basement. Concrete piers are recommended because they can be safely installed using some conventional tools. They are also less expensive than steel piers; moreover,they don’t rust or rot. They last for many decades.
The repair project isn't completed with the insertion of concrete piers. These piers are a medium for introducing a more durable basement support structure, such as concrete spacers. Once the piers have been established, hydraulic jacks are placed along them and the basement is lifted every so slightly. Then, concrete spacers are inserted upon on the piers. The process creates greater support for the foundation.
Advanced Foundation Repair Using Mudjacking
Mudjacking is a common advanced foundation repair method. It is recommended when the basement shows signs of sinking in the underlying soil. The symptoms of this problem surface in the form of repeated basement flooding or extensive moisture seepage. The foundation of a house can sink because of the increased weight of recently-added floors to the house, or changes in the sub-soil.
Mudjacking is the process of literally lifting a home by adding loads of concrete under the existing basement. In mudjacking, small holes are drilled around the perimeter of the foundation. These holes are then pumped with a mixture containing cement, soil, or grout in various proportions. Low-strength concrete is recommended for this kind of foundation repair.
Mudjacking is also called slab-jacking and is regarded as one of the most undemanding and affordable ways of saving a deteriorating basement. A house can be lifted nearly 6-inches using this technique. The presence of fresh, underlying concrete adds decades to the overall life of the basement.
Some landscapers recommend using polyurethane resins instead of concrete. Though this might be a more durable option, particularly if the sub-soil is excessively wet, it can considerably raise the overall costs. The bigger advantage is that greater basement lifting can be achieved using resins. The resin-mix produces gas and bubbles in large quantities when it is pumped into the drilled holes. The expanding volume of the gases lifts the overlying building by several inches.