Opening a hole for the helical piers
The crew dug a few holes to install the helical piers. They noticed that something was off and called in their foreman, Kenny. He saw that there was too much concrete attached to the wall. Basically, when the church members had fixed the sinking foundation, they added a heavier footing to the building. This acted as an anchor and pulled the wall down faster.
Kenny looking for the actual footer
Production Manager, Kenny Sharpless, is looking for the actual footer of the building. His entire arm is up inside the cavity. We later discovered that the building had been rebuilt several years ago and additional concrete was poured to support the wall. The newest concrete was around 20 years old and around 10 inches thick. It started right about where Kenny's chest is in this photo.
Close up of the open cavity
Normally there is only about 4 inches of what is called "over pour" on an exterior wall. The crew quickly discovered that the concrete extended almost 2 feet from the building. In order to properly install the helical piers and attempt to lift the building back to level, they would have to remove all of this excess concrete.
Drilling the holes for concrete removal
See how high up on the building he is standing? Normally the footer is several feet down in the ground. There is a 3 foot high crawlspace under this church, so he should be standing up to his waist. That gives you an idea of how much extra concrete has to be removed. The reason for drilling holes is to have nice clean breaks when using a jackhammer. This makes less chance of harming the building itself.
Exterior wall cracks in the foundation
You can see just how severe the cracks in the wall are in this picture. The plywood is there because we asked the church members to remove the windows. The thought was that if we tried to correct the problems, it could shatter these windows. This is one of the most extreme cases we have dealt with here at DryZone.
Using a hammer drill
The hammer drill is a tool that our crews use to get a nice clean edge on the concrete base. The helical piers, and more importantly the bracket that holds them in place, needs to be flush to the wall. If we tried to install the piers on an extended piece of concrete, the pressures created by trying to lift up would snap off the concrete. This is not only ineffective, but incredibly dangerous too.
Bringing in the mini excavator
After finding all these issues, the crew decided that they needed to see how far out the extra concrete came out from the building. This is when they discovered that there was almost a 2 foot extension on the building. We estimated that there was close to 2,000 pounds of extra concrete in the ground. Can you imagine that kind of weight pulling down on the building?
Jackhammered hole to install the helical pier
See how far out from the building this is? Normally we install the piers right up close, but this is a test hole to see how far down the extra concrete goes.
Very thick concrete
There was roughly 30 inches of hardened concrete attached to this foundation wall. Is it any wonder that the building was sinking into the ground. Normal footers are around 8 inches thick.
Bracket for a helical pier
Each helical pier that we install is fixed to the building's foundation with a specially designed bracket. We design our foundation repair systems to have minimal slipping and rotation so there should never be a need to do the job over.
Driving the helical piers
The red thing at the top of the picture is the drive head for what we call our "giant screwdriver." Basically we take the digging bucket off of our mini excavator and attach the drive head. After that, we screw these piers into the ground.
Our mini excavator
This shows you just how the task of supporting a sagging foundation looks like.
All finished
So once all the steel is in the ground and the building is supported, we fill in the holes. When we leave, the building is fixed and the yard looks pretty much undisturbed.