Settling Foundation

Thursday, December 1st, 2016 by Niles Erickson

Challenge

This ranch house in Melrose was settling due to unstable soils underneath the home. The customers had been seeing cracks in their walls throughout the house and attached garage, as well as in the floor in their finished basement. The basement was an open concept with two columns supporting a few steel beams. The beams themselves were sinking and bending with the settling of the house. Lastly, there is a chimney running from the middle of the house up through the roof. The chimney was also sinking.

The homeowners could not wait any longer for repairs to be made, as windows and doors were getting stuck, and they were at risk of extensive damage happening to their house.

Soils under the house were very 'sandy' and loose. Upon excavating down on the exterior of the foundation, we also found the water table was incredibly high in this neighborhood. Essentially, water was running under the home and washing away the soft soils where the foundation was lying. A large void was being created and the home was loosing it's foundation right out from under it. We also had to pump water out of the holes we dug along the foundation walls in order to install our piers.

Solution

The solution for repairing the foundation of this home was installing push piers at various locations on the foundation.

Firstly, we excavated down on the outside of the foundation along the front and side of the house. Push piers were attached to the footings and pushed down to depths up to 40 feet. This depth was required in order to reach bedrock, ensuring the piers would fully support the home and not sink in similar unstable soils.

Along the inside of the home, we also removed some of the concrete surrounding the footing of the chimney, and attached 3 piers here. These were also pushed down to depths around 40 feet, as the soils were so unstable. Water was immediately visible at just a few feet down, showing that the high water table was most likely eroding away the soils under the homes foundation.

After all the piers were installed, fully supporting the foundation and preventing it from sinking any further, we also installed SmartJack posts inside the basement. The SmartJacks were used to support the beam in the basement which was bent and sinking. With the SmartJack system, the beam was cranked up a few inches, helping to straighten out the beam and preventing it from sinking or bending further.

Overall, with the push piers installed throughout the house, the home will no longer be at risk of settling or sinking. With the foundation now supported by the piers and bedrock, the problem soils are no longer a factor.