FEATURE 19
• Rigid and durable if the correct pipe is used in the correct application
• Easily available
• Affordable compared to other materials
Disadvantages of PVC pipe
• If PVC pipes burn in a fire, several toxic gases can be released into the air, such as hydrogen chloride gas( HCl) and carbon monoxide.
• There are many non-compliant options on the market.
• If plumbers don’ t read the markings on the pipe, it could be installed in the incorrect application.
• If exposed to sunlight, PVC pipes can become brittle over time.
Methods of connecting PVC pipe Unlike steel or copper piping, PVC pipes cannot be connected through soldering. There are four main methods of connecting PVC pipes, including: 1. Solvent weld / PVC glue 2. Rubber ring / rubber insert joints 3. Flanges and flange adaptors 4. Male to female connections and adaptors – used where PVC transitions to other materials or fittings
Busting common myths about PVC piping
1.“ All PVC pipes are basically the same.” You need to look at the make, brand and specs of the pipe to ensure that your pipe choice is compliant to the application you intend to use it for.
2.“ If it’ s PVC, you can use it anywhere.” The label on the pipe will tell you what it was designed for, its class and pressure rating, and whether it is for underground use only or whether it is UV-resistant. PVC is not a one-size-fits-all product.
3.“ If it’ s cheap and it works, it’ s the right choice.” There are applications for cheaper and lighter pipes, such as sleeving. However, one must distinguish between temporary / sleeving use versus long-term functional pipework, and not just look at the price. 4.“ PVC pipe lasts forever.”
PVC does deteriorate, just more slowly than other materials.
5.“ If I just paint the PVC pressure pipe, then I can install it in sunlight.” SANS 10252:1 states that no PVC pipe may be installed in above-ground applications( this excludes drainage applications such as sewerage). PA
Supplied by Steyn van Zyl
Wall thickness if pipe is 110mm, underground pipe 2.38mm.
PVC versus HDPE drainage pipes If you are unsure whether to use PVC or HDPE pipes for your drainage application, the below information gives a comparison in terms of uses, advantages and disadvantages.
PVC drainage pipes
• Rigid, lightweight and cost-effective
• Easy to install with solvent or rubber ring joints
• Commonly used in residential and standard commercial buildings
• Best for normal domestic drainage applications
Advantages:
• Lower cost, easy installation, widely available
Disadvantages:
• More brittle and less flexible under movement or impact
HDPE drainage pipes( high density polyethylene)
• Flexible, strong and impact resistant
• Joined by fusion welding for leak-resistant systems
• Commonly used in high-rise, industrial, and heavy-duty applications
Advantages:
• Handles movement, vibration, chemicals and higher temperatures better
Disadvantages:
• Higher cost and requires specialised installation
The rule of thumb
• PVC = economical and ideal for standard drainage
• HDPE = better solution for demanding applications and larger buildings
August 2026 Volume 32 I Number 06 www. plumbingafrica. co. za