Acoustic Performance

FACT: Cast iron is the best performing material acoustically and Ensign EEZI-FIT is the quietest system on the Market!
How do we know? Because we have test results to support it.

Acoustics Comparison Test
Undertaken by Saint-Gobain PAM UK and carried out at the IBP Fraunhofer Institute Laboratory, Stuttgart, Germany.

1. Measure levels of noise transmitted through different PAM ranges of cast iron above ground systems when installed to the criteria laid down in BS EN 14366: 2004

2. Achieve an acoustic performance measurement that specifiers can trust as having been tested in a recognised independent laboratory to the appropriate standard

BS EN 14366: 2004 was introduced to allow consistent measurement of all drainage systems and materials, in order for specifiers to make true comparisons.

Systems Installed

  • Ensign EEZI-FIT Push-Fit to BS EN 877
  • Ensign Mechanics System to BS EN 877


  • Vertical stack assembly over 2 floors tested with a range differing brackets, 2 brackets fitted, no seal through the floor (see diagram test criteria)
  • Flow rates measured at 2, 4 and 8 litres per second
  • Important: when comparing results - ensure the flow rates are the same
  • Important when comparing results with manufacturers claims – ensure the flow rates are the same and that 2 brackets are included

Material / systems Bracket used Airborne Noise
Structure-bourne Noise
2L/s 4L/s 8L/s 2L/s 4L/s 8L/s
Cast iron            
Ensign 100mm EF048 45 48 54 27 32 34
Rubber lined Steel 48 51 53 19 24 32
EF048AD 45 47 54 5 11 19
Ensign 150mm EF048 49 51 54 16 19 24
Rubber lined Steel 48 50 54 22 25 30
EF048AD 49 52 54 10 14 21
EEZI-FIT 100mm EF048 45 48 51 23 28 36
EF048AD 45 48 51 4 9 17
Standard 100mm Rubber lined Steel   55     31  
Acoustic 100mm Rubber lined Steel   52     20  
Twin Wall PVC 100mm Rubber lined Steel       12 20  
Stainless Steel 100mm Rubber lined Steel 52 54   22 26  
PVC 100mm Rubber lined Steel 53 57   22 28  

i.EF048 Bracket = ductile iron bracket
ii.EF048AD Bracket = ductile iron bracket fitted with acoustic dampener

Figures listed in this table are taken from tests done by Saint-Gobain or previously published by manufacturers.


When installed with acoustic brackets EF048AD, Ensign EEZI-FIT is proven to be:

  • Up to 11 dB(A) quieter than acoustic HDPE
  • Up to 17 dB(A) quieter than stainless steel
  • Up to 22 dB(A) quieter than standard HDPE
(Structure-borne noise measurement)

Ensign and Ensign EEZI-FIT should not require lagging to meet Doc E Building Regulation Guidelines for habitable rooms, making it once again a value choice based on potential insulation costs of up to £15 per metre for other systems to match the performance of cast iron.

>> Click here to hear the difference between our Cast Iron Soil System and standard HPPE or UPVC pipework.

>> Download the Acoustic whitepaper: "When put to the test a sound argument delivers cast iron evidence."

>> Find out more, contact us today.