Project: Foundation Repair Using Underpinning

About this Project

A foundation repair using underpinning is often a great start to resolving several structural issues. A homeowner may only notice a crack in a wall, a corner out of plumb, or a sloped floor or roofline. However, when a professional structural engineer can evaluate the home in its entirety, the cause of these issues can be determined. Furthermore, other issues that may not be noticed can also be discovered. The best news is, that most can be resolved, often starting from the ground up!

An inspection by Penn Valley Engineering was completed at a home in Ewing, NJ 08628. The 1975 home was a 2-story conventional wood-framed home with an unfinished basement. The home had an attached 2-car garage and an elevated wood-framed deck at the rear of the home. Observations showed many reasons for the need for foundation underpinning in an effort to repair the foundation.

Determining the Need for Foundation Repair Using Underpinning

Our structural engineer examined the block masonry foundation system, the roof framing, the rear deck, and the storm water management characteristics of the interior sub-grade areas and exterior perimeter. Despite an attempt to repair the garage floor slab and replace the front porch, the troubled foundation continued to cause damage. The most likely cause of the differential foundation settlement movement was poor soil conditions below the footings.

Our structural engineer noted:

• Vertical cracks on the foundation walls along the front, right side, and rear of the basement
• Vertical cracks along the left side and rear of the crawl space
• The left side foundation wall along the garage was not vertically plumb and was rotated/shifted outward
• Garage floor slab showed signs of settlement and cracking
• Sagging roof over the garage
• Sloped roof on the covered front porch
• Deteriorated wood on the elevated deck
• Improper footings and post conditions when the deck was constructed

Underpinning the Foundation

To remediate the cause of the cracks and out of plumb wall, underpinning the affected foundation segments was required. Installing a series of helical piles with side load brackets attached to the existing footing would prevent further movement and cracking. The foundation wall and footing along the left side of the garage would possibly need to be removed and replaced along with the garage floor slab.

Deck Repair or Deck Replacement?

The elevated deck attached to the rear of this house was not constructed properly and the wood was deteriorated. Improper footings and conditions for the posts caused inadequate support of the deck, rendering it unsafe. When you are unsure whether to repair a deck or replace it, call PVE for a deck inspection. When possible, deck repair is a great way to save money. Our recommendation in this situation was to remove and replace the entire deck.

Eliminating Basement Moisture

Once the foundation repair using underpinning and the existing footing is verified, the homeowner can then repair another structural issue – water intrusion and high moisture conditions in the basement. When water/moisture conditions cannot be cured by exterior perimeter improvements, i.e. re-grading and gutter extensions, then it is recommended to install a complete perimeter sub-grade drainage system. Read more about foundation drainage.

In this case, it would be required along the interior perimeter foundation walls – approximately 162 linear feet. In addition to this repair, our structural engineer recommended installing a dehumidification system to improve the water and moisture conditions in the basement.