Real Estate and Foundation Underpinning

C. Sherman Henes and Cassi Henes

Homebuyers frequently call our office for advice or just to have a question answered. I answered a question today that I thought would make an excellent article, so here it goes.

The homeowner contacted us because she is purchasing a new home. She received an engineer's report calling for "foundation underpinning" and wanted to know if I had ever heard of it. As fate would have it, I happen to work for a company that specializes in foundation repair, which includes underpinning!

Foundation unpinning is a class of foundation repair that includes push piers, helical piers, deep foundation piers, caissons, and other support systems. The specific system that I discussed with this homeowner is the push pier system.



When a home is settling or cracking, it is caused by soil movement beneath the foundation. In order to combat this problem, engineers developed systems that move the weight of the home off the unstable soil onto a stable bedrock support. This is accomplished by hydraulically pushing galvanized steel piers down through the ground until they reach bedrock. The weight of the home is then transferred on to the piers by using rugged steel brackets attached to the footing of the home. Each individual pier bracket and pier combination can be adjusted to make the entire home level.

The foundation pier system is guaranteed against movement and fully restores the home to livable, secure condition.



The homeowner wanted to know if this was essential. This is how I put it, "how much risk are you willing to take with your investment?" An engineer has determined that the home has significant enough concerns to warrant recommending a full foundation underpinning project. This means that the engineer has seen indications that the entire foundation is moving, not just a portion of it. The home inspector has determined that levelling compound was utilized at least twice on the basement floor. He also stated that there have been a series of drywall patches and stucco repairs both on the interior and exterior of the residence.

In other words, you have physical evidence that the home has moved in the past and been repaired. You also have an expert telling you the home has moved, is moving, and will continue to move. Do you want to assume the risk to your family and your investment by purchasing the property as is?

This is not the end of the story; however, there is a happy ending to this unpinning question. I told this lovely homeowner that you also can know the exact cost to never worry about this problem again. You may be able to either get money off the home, or cut a deal with the sellers to cover a portion of the costs. Or you may discover that the cost is within your budget to repair the home.

I sent a Structural Specialist out to do a free estimate on the home and he came back to her that day with the repair outline. The home needs approximately 15 piers to go around the entire perimeter of the home and lift it back into stable condition. The sellers and buyer met together and decided to drop the price of the home by the amount of the repair and the transaction is back on track.

How will I know if a Home has a Structural Problem

by C. Sherman Henes and Cassi Henes

Throughout this summer, Peak Structural will be bringing you important information about the structural integrity of your home. In fact, we'll be featuring Jeff Kortan, P.E., the Director of Engineering with Foundation Supportworks. Mr. Kortan is a nationally recognized author, speaker, and geotechnical engineer, who has been an integral part of the team developing the latest in Foundation Repair technology.


Here's an excerpt from Jeff Kortan, P.E.'s four part article, featured in the NAHI (National Association of Home Inspectors) Forum Magazine:

HOW WILL I KNOW IF A HOME HAS A STRUCTURAL PROBLEM?

A home with a settling foundation may display cracking of exterior cracking, in drywall, and at the corners of door or window framing). Doors and windows may be out of level and difficult to open and close. Floors may also be out of level and concrete floor slabs can display cracking. Evidence of past repairs, such as tuck-pointing brick or patching drywall, are also possible indicators of a settlement problem.

Symptoms of failing basement walls in a home will look different depending upon whether the walls are constructed of concrete block or poured concrete. Concrete block walls will typically bow in at the middle (rather than lean in at the top) and show stair-step cracking at the corners with a horizontal crack across the center. On the other hand, poured walls will typically display diagonal cracks extending upward from the bottom corners of the wall toward the top center. The top of the wall near the middle tends to lean in. Failing basement walls can cause ceiling panels and ceiling drywall to buckle, and cause the drywall on finished walls to crack.

Look closely within crawlspaces for structural problems. Sloping or sagging floors may indicate problems in the crawlspace area below. Sloping or sagging floors are often caused by weakened floor joists due to excess moisture and wood rot in the crawlspace, improper spacing of floor joist support beams or settling of existing interior columns.

HOW DOES A HOMEOWNER FIX A STRUCTURAL PROBLEM?

The good news is that there are solutions for each of these types of structural problems, and the cost is not necessarily excessive. Depending on the problem, piering and/or anchoring systems offer quick and permanent solutions for foundation defects. Rather than dealing with the high cost and inconvenience of total foundation replacement or living with a significant reduction in property value, piering and anchoring systems can restore property value and give both home sellers and home buyers peace of mind.

HOW CAN YOU USE THIS INFORMATION?

As a home inspector, your credibility lies in your ability to accurately identify potential structural problems. Over the next three articles in this four-part series, we’ll take an in-depth look at how to identify foundation settlement problems, failing basement walls, and settling columns or sagging beams in a crawlspace. We will also examine different options for repair and the pros and cons of each solution. Your ability to diagnose structural problems will be highly beneficial to your clients.

How Does a Wall Anchor System Straighten a Wall

by C. Sherman Henes and Cassi Henes

Here's a great question from Adam in Littleton, CO:

How does the anchor system you talk about pull the whole wall and not just tear through the concrete into the backfill?

In the case of a typical job where Peak does not do a full excavation on the outside of the home's foundation wall, the soil remains in place. If we were to pull on the anchor as much as required to move the wall back to vertical, then the anchor would almost certainly pull through the wall. This is not; however, what we are doing. We are applying a known force to the wall which is mostly absorbed by the soils on the other side of the wall. It relieves the wall enough that it stops bowing. In many cases, the wall can be brought back to vertical over time. This is because during dry periods, the soilds can shrink away from the wall and relieve the pressure on both the wall and the anchors. If the anchors are tightened during these dry periods, it brings the load in the anchors back up to their installed load and removes the space created by the drying soils. Repeating this cycle can; therefore, straighten the wall over time. In more simple terms, we are not forcing the wall back to a straight position, we are applying gentle, but sustained, load and moving the wall only as much as the surrounding soils will allow.
--Aaron Henes, Systems Specialist

"Bowing walls that require a full excavation are straightened during installation because with the soils removed, there is far less lateral pressure to overcome and the wall has enough internal strength to carry the smaller forces required to straighten the wall".
--Michael Sullivan, P.E.