Case Studies

Rainy Day Basement Systems Case Studies: Push Pier Installation in Arlington, WA

Thursday, December 7th, 2017 by Bayleigh Stelling

Challenge

Karl W.’s Arlington house is built on a hill, and over the years he and his wife noticed that it was steadily settling over time. The mixture of gravity and unstable soil was causing the house to slant downhill. Doors were not shutting, drawers refused to stay closed, there were cracks in the walls and the floors were settling in the middle. To eliminate these issues and increase the life of his home, Karl contacted us for a foundation restoration plan.

“I chose Rainy Day even though I got bids from some other companies first of all because I know Dan very well,” said Karl. “I trust him. He’s a very forthright person. And, I have talked to other people who have had work done by him and they were very very pleased. So, that made up my mind that I am going to go with Rainy Day.”

During Karl’s free inspection and estimate, we took preliminary measurements and concluded that his house was settling in multiple locations. There was a considerably large amount of unstable soil under the foundation of the home. The poorly compacted fill soils on the hillside was causing a lot of backfill on the retaining wall that the house was on. Essentially, the house was built half on backfill, causing destabilization that was going to worsen over time.

Solution

Following the second evaluation inspection, it was decided that in order to achieve re-stabilization, steel push piers would have to be installed in various parts of the ground, each going into different depths of the earth to ensure stability. After an excavator dug around the house, we began pier layout, digging holes in the internal and external sinking areas. With each location, we prepped the footing, determining exactly how high and deep each pier needed to be.

The placement of each pier was decided on where the house was unlevel, where the soil was unstable and where stable PSI (pounds per square inch) needed to be implemented. We set up the piers, placing them in the needed areas and lifting them to a level location. Each pier was then inserted down into the ground with steel tubing at different depths, ensuring that each was in solid soil. We installed 15 total piers, the deepest going 22.17 feet into the earth and the shallowest going 16.17 feet. During the process, we checked with Karl to ensure that the leveling was satisfactory.

When all steel push piers were stable, controlled density fill (CDF) was installed in the areas of the house that were stiff and experienced a blowout from the shifting and leveling. CDF is a backfill cement-like material that is self-compacting, and inserting it into the areas of the house that were significantly sunken-in from years of foundation settling, gave stability to the housing structure.

We benchmarked the house after the lifting equipment was removed, placing little level indicators around the house. This gives Karl the ability to know right away if his house ever shifts.

“Just like clockwork, everything got done just like Dan had prescribed on time. Super super nice crew and never once was there any problem with neatness or being careless. It was just a super job,” said Karl.

The renovation resulted in Karl’s house being completely level once more, and the problems that he was experiencing ceased to exist.

“The most noticeable difference right off the bat is our house is now level again,” said Karl. “Doors that would not shut before, shut normally now. Office drawers that would never stay shut—I had to lock them with boxes to keep them shut—do not come open on their own anymore. It is perfectly level. We got it right back to its original position, which we never thought would happen. I was very appreciative and intrigued with the whole process of how Rainy Day goes about taking careful measurements before, during and after the whole process. They rely very heavily on that constant flow of data into the process to make sure that first of all they are doing the right thing at the right time, and that I am satisfied that things are going according to plan. I followed along as measurements were being taken and re-measurements were being taken, and it was really intriguing just to watch the whole process—how accurate and precise the crew was.”

Click here to view the video testimonial of this project. View this project's photo album for more pictures.