Settling Detached Garage Pepperell, MA

Challenge

This detached garage at a home in Pepperell, MA was facing severe settling issues. The slab on the interior of the garage had sunk in the middle up to 12" (1 ft) and had cracks all over. Additionally, the footings and walls on the perimeter of the structure were also settling and had cracks. The soils surrounding this entire garage were very unstable, and most likely not prepared correctly by the contractor involved in the building process. Upon excavation of the foundation, the soils were very soft and hardly compacted. We also found there were some old trees buried in the soil, which decayed over time and lead to shifting soils. Also found at the rear of the structure, the foundation wall was cracked and bowing out. 

Solution

Due to the various issues affecting the detached garage, several different areas needed to be addressed in order to permanently stabilize the structure. Erickson Foundation Supportworks proposed installing Push Piers along the perimeter of the foundation footings, helical piers under the slab on the interior to stabilize the center of the structure, and also SmartJacks above the helical piers to support the main beam in the garage. A total of 15 Push Piers were installed, as three sides of the garage needed stabilizing, and ranged in depth from 8ft beneath the footings and down to 20ft in some locations. While the Push Piers were being used to lift the structure a few inches, the back wall began to buckle and bow out, and so 3 GeoLocks were also added to the project in order to straighten this wall. The only other alternative to fixing this detached garage would have been total foundation replacement, which would have been a lengthy, costly project. The overall integrity of the foundation was still intact, and so by stabilizing the structure with deep earth solutions and reaching the better soils beneath the shrinking soils, the garage was able be completely stabilized.

*As a note: in most cases Erickson Foundation Supportworks will also propose using PolyLEVEL under slabs in order to fill the voids and lift them back to a level position. However, the void under this garage slab was immense, and the entire 30' x 20' area of soil beneath the slab had sunk, with some places up to 1 foot of settling or more. Due to the amount of PolyLEVEL required to restabilize such a slab area with large voids, Erickson Foundation Supportworks recommended the homeowner consider removing the existing concrete in order to bring in more soil, which should be properly compacted, and then repour a new slab. While PolyLEVEL could have bene used, it would have required an incredible amount of material.

Project Summary

Installing Contractor: Erickson Foundation Supportworks

Crew Leader: Stavros Charalambous

Certified Inspector: John Prince

Products Installed: Push Piers (15), SmartJacks (2), Helical Piers (2), GeoLock Anchors (3)