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PLUMBING CONNECTION
WINTER 2015
with a device to calculate the sound coming through on the
other side. We can’t put a speaker in a pipe though.”
Acoustic lagging comprises a noise barrier to contain
pipe-wall vibrating noise. There are several types of
materials used for this purpose, including loaded vinyl and
convoluted foam. Each material will have a U-Factor, which
is a performance rating that measures how well a given
material prevents heat from escaping.
Let’s look at available products from three reputable
Australian suppliers.
ACOUSTICA GREENLAG
GreenLAG® pipe lagging was developed to contain
the intrusive noise generated by the turbulent flow of
wastewater through pipes, fittings and general noise break-
out from ductwork, fan housings and the like in residential,
commercial and industrial buildings.
Philippe Doneux, Engineer at Acoustica describes some of
the benefits of its product.
“GreenLAG uses a soft and cellular structure which
increases vibration dampening. This allows for us to use
15mm foam as opposed to 25mm which most others use. It
also means that for a given weight and thickness, GreenLAG
will achieve a better STL (Sound Transmission Loss) than
other products in the market.”
Acoustica also claim that another direct consequence
of reducing material thickness is the reduction of the
vibrations radiating surface, when lagged over pipe.
Pipe lagging has traditionally known to be laborious and
time consuming; however Philippe believes this is changing
thanks to experience and advanced skill sets.
“The professionals lag quite quickly now and teams of
people exist who specialise in the field. These guys don’t
need to take patterns to cut for different junctions and the
like – they can do it all by eye now. It’s a bit like the old metal
workers who could cut metal the right way.”
Keeping the installers happy by working into their regimes
makes it all the more straight forward too.
“Depending on how the laggers like to have the material,
we supply it in different lengths. There is a company in SA
that uses women to do the lagging so they ask that the rolls
of lagging are not overly heavy. We provide them with 3m
lengths by 1.3m wide. We can supply in longer rolls up to
5m by 1.3m wide as well. We’ve definitely noticed a shift to
shorter rolls though. It makes for easier navigation through
stairwells and other tight spaces.”
When it comes to installation, Philippe assures that
working with GreenLAG is simple and straightforward.
“It’s very easy to cut with a knife or scissors, particularly
with the thinner material being employed. We suggest to
installers that they always overlap by about 50mm rather
than butt joining the material. We also suggest they use a
longitudinal reinforced aluminium tape that goes over the
ACOUSTIC PLUMBING
Acoustica GreenLAG uses 15mm foam rather than 25mm.
They claim that the soft cellular structure helps to achieve a
greater Sound Transmission Loss than other poducts.
NCC 2011 REQUIREMENTS: F5.6
Sound Insulation rating of services a) If a duct, soil, waste or water
supply pipe, including a duct or pipe that is located in a wall or floor
cavity, serves or passes through more than one sole-occupancy
unit, the duct or pipe must be separated from the rooms of any
sole-occupancy unit by construction with an Rw + Ctr (airborne) not
less than - i) 40 if the adjacent room is a habitable room (other than
a kitchen); or ii) 25 if the adjacent room is a kitchen or non-habitable
room.
b) If a storm water pipe passes through a sole-occupancy unit it
must be separated in accordance with a) i) and ii).