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PLUMBING CONNECTION
WINTER 2015
FINDING THE RIGHT BALANCE
P
lumbing is no longer a
straightforward process. Rapid
changes in plumbing materials
and fittings’ means that using just
one system may not provide added
advantages in terms of cost, time
and ease of installation. In fact a new
study suggests that mixing plumbing
systems is by far the best approach.
The Copper Alliance Australia
commissioned one of the most highly
regarded, independent plumbing
system estimators in the business,
Mr Nigel Essex of SX Estimates from
Sydney, to compare the costs of
different plumbing systems for a
medium size commercial building. The
estimates were based on a typical 10
story hotel building and included the
costs of both labour and materials
based on average commercial market
material purchase and labour cost
rates. A hotel includes a large amount
of hydraulic services due to there being
a bathroom within every room.
The building consisted of 175 typical
hotel rooms and main distribution
pipework with the DCW (domestic cold
water) being measured from the outlet
of the property’s water meter and
include the basement level fire hose
reel. DHWF (domestic hot water flow)
& DHWR (domestic hot water return)
has been measured from the roof plant
room heaters. For the exercise non-
typical areas have not been measured.
DIGGING DOWN
The estimate used was compiled
in accordance with the Australian
Standard Method of Measurement
and for the purpose of this study
only pipework and fittings have been
considered. Other components such
as plant, valves etc. have not been
measured as the repetitious costs are
the same for all estimates.
Estimating rates were based on
net material for fittings, net cost for
pipe and tube with 5% allowance for
cutting and waste, a base labour rate
of $80 per/hour and average costs for
brackets, fixings and sundries. Project
specific preliminary costs have not
been included in the estimate.
The comparison was conducted on
one or a combination of the following
pipe systems:
∫ Copper incorporating silver brazed
fittings (CTS fittings)
∫ Copper with Press-Fit fittings (both
full range and ≤ 50mm)
∫ PE-X
∫ PP-R
∫ Stainless Steel with Press-Fit
fittings
As each of the plumbing systems
have advantages in a particular size
range and application, the estimate
was broken down into three sections
being:
1. Roughins (Small diameter 15-20mm
mainly to plumbing outlets)
2. DCW – Domestic Cold Water
(≥25mm-100mm diameter cold
water plumbing)
3. DHW - Domestic Hot Water
(≥25mm-to 100mm hot water
plumbing)
TOTAL INSTALLATION COST
Various combinations of systems
were assessed with some interesting
outcomes for the most cost effective
solutions. Figure 1 shows the results
for the comparison of the best options,
separating the cost elements by labour
and materials.
PLUMBING ANY SORT OF BUILDING IS A COMPLEX PROCESS AND COST IS JUST ONE OF THE FACTORS, BUT A NEW
STUDY SHEDS SOME LIGHT ON BEST PRACTICE SAYS COPPER ALLIANCE AUSTRALIA’S
JOHN FENNELL.
COPPER CONNECTION
JOHN FENNELL
FIGURE 1
FULL INSTALLED COST
INSTALLED COST ($)
$
$50,000
$100,000
$150,000
$200,000
$250,000
$300,000
$350,000
$400,000
$450,000
PE-X Roughin
Cu PressFit
< 50mm Cu
CTS>50mm
PE-X Roughin
Cu CTS
25-100mm
PE-X Roughin
Cu PressFit
25-100mm
PE-X Roughin
PP-R (DCW)
Cu CTS (DHW)
PE-X Roughin
Stainless
PressFit
25-100mm
Full Cu CTS
15-100mm
Full Cu
PressFit
15-100mm
LABOUR
MATERIALS