This is part of a continuing series. Don’t be mis-lead by deep discount foundation repair .

A disreputable foundation repair company will short drive piers/pilings. Saves on material cost and installation time.   It is easy to drive short pilings in clay soil when concrete cylinders are used.  And for a couple of years, all will look fine.  But don’t be mislead.  Read on:

Pressed concrete piling depth is achieved by using hydraulic force against the weight of the house.  The dryer the clay, the more force is required to achieve pier depth.   The goal in driving pilings is to drive downward to the zone of minimal seasonal moisture variation, or rock.  At the zone of minimal seasonal moisture variation, the pier provides maximum long term support.

Four most concrete slab house repairs, at Granite Foundation Repair, we prefer steel pilings, which always drive to rock.  A lot can be done though to drive concrete cylinders/piers/pilings to maximum depth.  During dry weather, there are several tricks that a discount foundation repair company can use to level your house while attaining a pier depth of 3-5 feet.  This depth is good enough to lift the house, but not to provide long term stability.

What is the foundation repair company’s warranty and remedy for a sinking pier?  ADD MORE STEEL SHIMS. That often fails to stop future subsidence.

Here are 3 ways to achieve maximum depth, maximum stability, which the discounter will avoid:

1. Water injection:  At Granite Foundation Repair, we typically hydrate dry clay soil in 3-5 spots per pier using high pressure water injection.

2. Slow, steady hydraulic driving: A patient installation crew member can achieve 2-5 more feet of depth by using a slow push.

3. Don’t take breaks: When the drive of a single piling is interrupted for more than about 20 minutes, the force to resume the drive increases exponentially with time.  During a drive, a cone of soil occurs at the end of the concrete pier. When the drive stops, the cone disappears.  Resuming the drive means overcoming the forces of flat clay resistance.  Also, during a continuous drive, clay particles slip past the porous concrete. Stop the drive and the clay sticks to the cylinder.

Good stable foundation repair is as much about the process as it is about the base material.  Discount foundation repair is all about taking shortcuts to save the installer money.  In the long run the homeowner may have a lot more problems as a result of deeply discounted foundation repair.