Cracked walls might not be limited to your basement. When you notice cracks in your home’s exterior walls, or when doors and windows begin to stick or not close properly you could be experiencing foundation settlement. This problem frequently occurs in areas that are composed of highly expansive clay soils or contain deep veins of soil high in organics such as peat moss. As the soils dry out they shrink. When the soils become saturated with water they swell and heave. Water tables also may rise or fall with the weather or an increase in new building construction in the area. When you notice settlement cracks you will usually find that the foundation footing has fractured due to this soil expansion and contraction. Without a solid footing, the foundation will continue to move and rotate throughout the seasons according to fluctuating ground moisture levels. To prevent additional settlement damage the structure must be stabilized.
If you have settlement problems, vertical helical piers must be installed to anchor the home to nonexpansive solid ground. The cost of this repair is dependent on the depth necessary to reach bedrock. This is something that can only be estimated prior to the work being done. Most piers are installed along the outside perimeter of the home. The excavation width along the repair area is normally 3′ wide. An additional 6′ is required for excavated material. This means that concrete floors, patios, decks, flower beds, trees or any other obstruction within 9′ of the home must be removed first.
The position of each pier is marked and then the footing at each location is prepared for the pier support bracket to be installed. Once the brackets are in place the piers are installed. The helical piers are hydraulically twisted into the ground. Extensions are added as required to add length. Once the pier has reached a stable stratum, which is determined by achieving maximum torque, installation is terminated and the pier is then connected to the support bracket. Once all the piers are in place the foundation can then be lifted (if required) back to the original elevation. A laser level is utilized to monitor lifting movement and assures that all locations are once again level. Once all the adjustments have been made the piers are locked into final position. Cracks are tuck pointed. The walls are then waterproofed. New drain tile is installed and the trench is properly backfilled.
Download entire Residential Foundation Anchors brochure (click here 1.75 MB PDF).
Download entire Resistance Pilers brochure (click here 1.63 MB PDF).
Respective sample pages below (material used with permission).