A plumbing test after foundation repair is required to protect you and your home from unnecessary damage.
Water from plumbing leaks is a major contributor to foundation failure.
Is a plumbing test essential?
When a foundation repair is performed in the vicinity of plumbing, a foundation repair company will always require that a licensed plumber check for leaks and that they be repaired. Leak test and repair is a standard condition in a foundation repair contract.
Possibly a leak was present before the foundation repair, and contributed to the need to fix the foundation.
Sometimes a leak occurs as a result of the house lift. As the foundation is raised, the plumbing remains firmly embedded in the ground.
If the leak is in the freshwater line, rapid soil erosion can take place, causing the foundation will drop.
When a plumbing leak occurs in the sewer system, it is typically slow. As clay soil absorbs water, it will expand, causing the foundation to heave. Heaving can occur over weeks or years.
At Granite Foundation Repair we have seen concrete slabs take a domed shape from the force of heaving clay soil. Additional water from a slow leak may turn the soil to mud. Muddy soil cannot support a foundation.
Foundation repair and plumbing issues sometimes go hand-in-hand. Be sure that you know the liability of your contractor before work begins!
So who is responsible for a foundation repair if plumbing issues occur?
Foundation repair contracts normally contain a statement similar to the following:
The foundation repair contractor is not responsible for pre-existing plumbing problems, or plumbing damage caused by lifting. The contractor will repair plumbing hit during excavation for pier installation.
To understand why the foundation contractor is not responsible for damage caused during lifting, let’s look at what is going on.
The drawing above shows a typical layout for a sewage line with some of the common leaks that occur. A freshwater line is similarly installed, running horizontally under the slab and then vertically rising to a faucet or other fixture.
As a foundation slowly drops, it pushes the plumbing deeper into the ground. If the plumbing did not get pushed downward, the vertical rising section of the plumbing would pop up through the floor.
In our example drawing above the plumbing is embedded in sand. Sand enables the plumbing to withstand some movement of the foundation.
Far too often, the builder may have taken shortcuts. Rather than thick, soft sand, the plumbing may be covered with hard, compacted clay soil. The hard soil grips the plumbing and resists the upward movement of the slab. During a foundation lift, the plumbing may be put under stress and may crack, resulting in a plumbing leak. There is no way of predicting which house will be affected. Short of not lifting, there is no way of managing the lift to guarantee that damage will never occur.
Four factors which influence the ability of plumbing to resist breaking during foundation repair:
- Soil density around the plumbing – can impede the plumbing rising with the house
- Extent of foundation drop – often times no problems occur with moderate foundation slumping
- Age and quality of plumbing – cast iron is particularly susceptible to aging
- Distance of plumbing away from the lift
All of these factors are beyond the control of the foundation repair company. They are related to soil, the extent of foundation degradation, and the condition of the pipes.
A foundation contractor has no idea as to whether the plumbing was properly installed in sand, or improperly buried in clay. The job of the contractor is to lift the structure as much as practical. Thus, sometimes a leak will occur.
Should the contractor hit the plumbing during excavation, contact with metal and the resultant leak is typically quickly apparent.
Freshwater leaks following a lift are rare as freshwater lines are rather ductile. Since the water is under pressure, a freshwater leak may be visible quite soon. Sewage leaks are un-pressurized and much harder to detect following a lift. Sewage leaks are more common in houses built with rigid, cast iron pipe. By the mid 80’s most city building codes had been amended to require the installation of more flexible PVC pipe for sewage lines.
Foundation repair and plumbing leaks should be handled properly to ensure quality work without complications and proper cost control. Since plumbing can be detrimental to a foundation and the repair work, a Contractor may require that the homeowner have a licensed plumber test for leaks and perform necessary repairs.