What is foundation drilling and how does it work?
Today, more and more houses are being built on unstable soils, such as those you learned about in previous chapters. Between expansive and hydrocompact soils and subsidence, the foundations are pushed and pulled, creating movement. Every year thousands of homeowners are faced with the evaluation and repair of foundation problems. Fortunately, this means that there are reliable engineering solutions available.
What exactly is available and is the right solution for your structural problems?
Since the root of structural problems is the soil, the first two solutions try to remove the weight of the foundations from unstable soils and place them on a bedrock or other stable soil; These solutions are called thrust piers and helical piers.
Thrust springs are basically long steel shafts that are hydraulically driven into the ground through unstable shallow soils until they reach bedrock or other load-bearing strata. Technicians can tell that the piers have reached the bedrock by measuring the hydraulic pressure required to push the piers into the ground until they reach the depth specified by the engineer. The weight of the house is then transferred from the unstable ground to the pillars via pillar supports attached to the base of the house.
Coil springs are similarly driven into the ground using hydraulics, but they turn into the ground like a giant screw. In fact, they are giant screws that literally hold up a house through the power of resistance. The weight of the house is then transferred to the pillars using the same durable steel supports.
Indications that you need a drilling system:
You have an area of your foundation wall that is experiencing vertical movement, such as caving.
Your fireplace is not flush with your home.
Your soil conditions can be classified as expansive, sunken, hydro-compactable, or active.
How to install the springs in 6 basic steps:
Step 1: Outside, the lawns and gardens around the house are removed and set aside.
Step 2: The soil is removed until the base of the concrete base is revealed.
Step 3: Industrial strength heavy steel foundation pillar anchor brackets are attached to the foundation of the house.
Step 4: Strong steel columns are hydraulically driven into solid bedrock or strata bearing the same load.
Step 5: The weight of the house, anchored to the steel supports, is carefully transferred from the unstable ground to the rock-solid pillars.
Step 6: After approval from an engineer, the land around the house is replaced and the landscape can be returned to its original location.
There are several other options that have been used at different times to solve foundation problems. The older method is to erect the house and replace the foundation and the newer method is to use drilling systems around the entire perimeter of the house or just part of it. Here’s a breakdown of the other methods people have used to solve foundation problems, from oldest to newest:
Replace Foundation:
It destroys the yard and takes several weeks to complete.
There is no guarantee against recurrence of the same problem (expect the same result
The shoes are still in the active zone
VERY EXPENSIVE- $ 50,000 MORE
Concrete supports / scattered footings:
It may take weeks / months
The added weight of the concrete can make the problem worse.
The structure cannot be lifted
The shoes are still in the active zone
Concrete piers:
Concrete cylinders may break during installation and CANNOT be recovered due to depths
The cylinders create too much friction on the skin to pass through the active zone.
May require additional shims in the future
Even if the shim is under warranty, excavation and rearrangement damage is not covered.
Square Shaft Coil Springs:
Originally designed to provide resistance to guy wires in electrical towers during high winds.
It is not designed to carry weight through the ground.
Square shafts bend and fold when the weight of a base rests on them.
Concrete piers with cable reinforcement:
Designed for specific soil conditions that are not present in Colorado.
The cylinders create too much friction on the skin to pass through the active zone.
The wiring in the center of the dock lengthens over time, allowing moment after moment in place.
Additional wiring on the outside of the cylinders can increase the surface friction of the cylinder.
Finally, drilling systems:
Push Piers WILL:
Allow the deepest penetration of any type of steel pillar.
Allow the possibility of low impact indoor installations (typically with much less collateral damage than outdoor approach)
Provide a lifetime warranty, transferable for the first 25 years so that no vertical movement occurs in the abutment areas.
It does its job in most soil conditions for a service life of more than 100 years.
Push Piers MAY:
Allow the ability to lift a structure to a flatter and more level condition
Allow the ability to close or shrink existing cracks in brick, stucco, plasterboard, or other interior or exterior finishes.
Allow for the realignment of glued doors or windows and the straightening of sloping chimneys.
Push Piers NO:
Guarantee that perfectly flat or level final conditions will be achieved
Provide lateral (horizontal) restraint to an arched foundation wall
Improve the watertightness or reduce the humidity level in a basement.
The coil springs WILL BE:
It does its job in most soil conditions for a service life of more than 100 years.
Allow installation on relatively older, weaker, or lighter foundation types
Allow installation as a pre-build (or new build) bearing system in poor soils
Allow horizontal installation as a “tie down” system to provide resistance against landslide on hillside areas.
With a few rare exceptions, they require exterior excavation, with destruction of the surrounding landscape or pavement.
Provide a lifetime warranty, transferable for the first 25 years, that no vertical movement will occur in the dock areas.
Coil springs MAY:
Allow the ability to lift a structure to a flatter and more level condition
Allow the ability to close or shrink existing cracks in brick, stucco, plasterboard, or other interior or exterior finishes.
Allow for the realignment of glued doors or windows and the straightening of sloping chimneys.
The coil springs do NOT:
Guarantee that perfectly flat or level final conditions will be achieved
Provide lateral (horizontal) restraint to an arched foundation wall (unless specifically installed in “tie down” mode)
Improve the watertightness or reduce the humidity level in a basement.