Water Hammer in SA Homes: Causes, Fixes and Arrestor Prices

Water hammer is the shockwave that hits when fast-closing valves (washing machines, dishwashers, solenoid-controlled taps) stop flow instantly. In older SA homes with copper pipes stapled to timber joists, it sounds like someone hitting a pipe with a spanner.

Why it matters

• Splits solder joints at 90 degree bends
• Loosens compression fittings behind walls
• Cracks toilet fill valves
• Voids your homeowner's insurance if a burst is traced to unfitted arrestors

Fixes ranked by cost

1. Turn down the stop-tap (free) , reduces flow but also pressure to showers.
2. Fit a PRV at the mains (R1,500 to R3,200) , see our PRV guide.
3. Fit mini water-hammer arrestors at the washing machine and dishwasher (R180 to R450 each) , simple screw-on units.
4. Fit an in-line arrestor on the cold feed (R650 to R1,200 installed) , for whole-house protection.

Brands available in SA

• Cobra Watertech (widely stocked at Builders and Brights)
• Sioux Chief (Leroy Merlin)
• Caleffi (specialist plumbing merchants)

Still banging after arrestors? The pipes are unclipped inside the walls or ceiling and a plumber needs to strap them. Get a quote.