While CPVC and PVC pipes are designed to last for decades, there are certain environmental factors that can cause them to fail prematurely. CPVC and PVC have a lot of the same characteristics and are manufactured very similarly. However, CPVC has a greater temperature range, which means it is better suited for hot water lines. CPVC also has a greater chlorine content than PVC because of the way it is manufactured.

PVC and CPVC Environmental Concerns

Both CPVC and PVC are subject to environmental stress cracking from a variety of sources, including the chemicals used by the water treatment plant, the acidity or alkalinity of your water, zinc from metal pipes within the system and from contact with certain chemicals, like spray foam.

Hydrolytic Degradation

Hydrolytic Degradation refers to the process of deterioration in plastics from excessive heat, UV light and exposure to acidic or alkaline conditions. When your plastic plumbing pipes come into contact with one or more of these conditions, the PVC or CPVC starts to lose its structural integrity because the properties of the plastic are fundamentally changed.

The most common form of Hydrolytic Degradation is the water flowing through your PVC and CPVC plumbing pipes. Water is almost never neutral, which would be a Ph level of 7. Instead, water Ph levels range between 6 and 8.5. Water that has a Ph level less than 7 can cause corrosion in metal pipes. If your plastic piping has metal fittings, the acidic water can cause those fittings to deteriorate, leading to CPVC and PVC pipe failures. Water with a Ph level greater than 7 is considered hard water. While there is no health risk, hard water can leave scale deposits on water fixtures.

Water Treatment Plant Chemicals

Certain water treatment plant chemicals, including chlorine and ferric chloride, can cause stress corrosion, which can lead to CPVC and PVC pipe failures. Over time, the chemicals used by the water treatment plant can cause the plastic to crack, leading to water leaks. The effects are typically most noticeable in buildings that reside close to the water treatment plant.


Zinc is found in brass and galvanized steel plumbing pipes. If your building or the municipal water system still contains brass or galvanized steel plumbing pipes, the zinc in these pipes can combine with chloride to form zinc chloride, which can contribute to PVC and CPVC plumbing failures.

Spray Foam

Spray foam is fast becoming the insulator of choice when it comes to residential and commercial buildings. This is because the foam can fit and expand almost anywhere, including around water supply and drain lines. Several manufacturers of CPVC and PVC have put out cautionary statements in regards to the use of spray foam around water supply pipes and drain lines as a preemptive measure because adequate testing has not been done to determine the effects of the spray foam when it is used to insulate around plastic water pipes.

Improving the Structural Integrity of Your CPVC and PVC Water Pipes with Nu Flow

Here at Nu Flow, we can help you determine the ages and structural statuses of your PVC and CPVC plumbing pipes, and we can help you repair any environmental stress cracking. This process involves performing a camera inspection of your water supply and drain lines to view any abnormalities, flaws and environmentally caused defects in your plastic pipes. Once we have the details, we will help you form a pipe restoration plan that may include epoxy coatings and pipe liners. We can even spread out your repairs over several months or years to help make the process more affordable for you and your residents.

To learn more about how our pipe restoration techniques can help increase the useful life of your water supply lines, call us at 815-790-9000.