Significant foundation failure with multiple roadblocks to achieving the desired outcome.
Challenge
BACKGROUND: This is a 2 story home with a fully finished basement. About 8 feet past the front door below the slab was a load bearing wall that ran the entire width of the home. We were informed this was poured as a monolithic slab. From the back part of this slab towards the front door spanning the entire width of the home was deflection in the neighborhood of 2-3’’.
What is deflection?! In engineering, deflection is the degree to which a structural element is displaced under a load.
While deflection was very obvious, there was little evidence of movement in the form of cosmetic damage inside the home. Having said that, there were some parts that were failing inside of the house that were away from the main perimeter area we would be working on the outside of the house. Floors were uneven and doors were sticking- both common settlement issues. On the exterior, there was evidence of movement, but nothing that would indicate such a drastic drop would be ocurring. No significant gaps to close and not much to actually “lift”.
Inspection/Recommendations: The initial inspection(s) were conducted by two separate licensed structural engineers. (Understand that that is not necesaary before having Redeemers Group come do an inspection; it is just the path this customer took). One strucural engineer came back with a recommendation of push piers and slab piers and the other came back with push piers and PolyLEVEL to fill the void created by the lift.
Once Specialist, Dan Brenner, got involved with the project, he explained to the home owner that slab piers would likely not help provide the desired outcome with a monolithic pour. In this case, the customer's desired outcome was to not only stablize the house, but have the house be level again if possible. Therefore, a proposed solution that included 21 push piers with 500 pounds of poly to void fill was ultimately accepted by the customer over several other companies and their proposed solutions.
Challenges: First, as you will see from the picture on the right, the slope on the west side of the house prevented us from getting an excavator to dig these holes. Piers numbered 19-21 all required holes that were 12-15 feet deep to find the footing.
Upon trying to expose the footing, our production crew was able to determine several things. First, we believed this home did not have a monolithic slab (see photo at right).
Second, once we had piers in place, we utilized enough pressure to see if we could get the house to move at all and it was then we realized there was some other factor preventing us from getting optimal results. The steel was literally bending: something that just doesn't happen without extraordinary or unusual circumstances. (see photo at right).
As it turned out, there was so much more weight added to the home because the customer had previously attempted to fix his problem with 6-8 areas consisting of concrete underpinnings.
Solution
At this time, based on the customers “do whatever it takes attitude,” we advised him that the best chance we had to obtain lift was to extract all of these areas. We recommended a 3rd party subcontractor that we have worked with many times in the past, and he came and removed everything in the driveway along with all underpinnings under the footing. This was our only chance to potentially allow us to achieve lift. In this process, the team now had room and access to do everything we needed to do.
To open everything up for us, the underpinnings and 25% of the driveway were removed. Upon doing so, the team found something else of interest. Not only had there been a previous failed attempt to lift by pouring a concrete underpinning, there had also been a previous failed attempt to lift the house using a competitor's jack. The competitor's jack was uncovered during the process.
In this case, a project that would normally take our team 4 days to complete ended up taking 8 because of the unusual factors in play. Without full disclosure on the front end about multiple attempts to correct the foundation failure by other companies, our team didn't have all the information they needed to know all of what would be needed to achieve the desired outcome: lift back to level if possible.
During the course of this project, our team determined that the house does not have a monolithic slab and that previous work has been done in the form of concrete underpinnings as well as helical piers from RamJack. Once we were able to work around the failed previous attempts, we were ready to lift the foundation back up to try to level his floors. (Keeping in mind he is looking for 2-3’’ of lift and there doesn’t appear to be any large visible cracks to close!)
Results:
Our experienced piering team was able, in this case, to lift the house back to level using our piers. They did a tedious and extraordinary job unncovering what roadblocks existed that were caused by competitors failed solutions, solved them, and not only achieved stabilization of the house, but the customer's ultimate desired outcome as well. The pictures to the right show 2 sets of before and after photos with the laser level line in them.
Why piers? When soils are unable to bear the load of the structure on top of it, that structure must sink downwards into the ground. This is true with homes, concrete floors, chimneys, and many other structures.
Piers can solve settlement problems by transferring a structure's weight to strong, competent supporting soils at greater depth. Piers can effectively stabilize a settling structure and can even provide jacking points to lift the structure upwards to its original, level position. The TYPE of piers will not always be the same from one home to another. As stated earlier, our Specialist determiend that push piers, not slab piers, would achieve the best result for this home. Click here to learn more about our different piers.
Once the piers were used to lift the house from the exterior, it was necessary to move to part 2 of the project: PolyLEVEL. Our PolyLEVEL Foreman used 500 lbs. of product to fill the voids created under the interior floors by the lifting back to level of the house. To learn more about how PolyLEVEL lifts sinking concrete, click here. To view other Before and After photos of where PolyLEVEL has been used unrelated to this project, click here.
As a side note: the reason we say "if possible" when discussing achieveing lift, is because the goal of any foundation repair is to stabilize the house or structure. That is the main goal, and that is what Redeemers Group warranties. Lifting the house back to level is always attempted, but it cannot be guaranteed. There are many factors that could prevent a house going back to level. This is part of the reason we would encourage anyone experiencing symptoms of foundation failure to have them looked at sooner rather than later. The longer floors are sagging or bowing or walls are cracking, the harder it is for them to go back to level.
Co-authored by Dan Brenner and Rosie Graves
Project Summary
Structural Engineer: Linda Prather
System Design Specialist: Dan Brenner
Foreman: Philip King
Crew member: Sam Smith
Crew member: Danny Wilkins
Crew member: Zach Cooper
PolyLEVEL Foreman: Joe Cook
Crew member: Daryl Brown
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