PM23 H1 Guide TUMU 210x287mm 4.0 LR - Flipbook - Page 8
CEILING
INSULATION
WALL
INSULATION
SUPPLIER SOLUTIONS – COMFORTECH®
SUPPLIER SOLUTIONS
Comfortech Building Performance Solutions® has a range of insulation products that
will meet – and exceed – the insulation requirements in walls
INSULATION
GUARD
SKILLION ROOF
SOLUTION
Under the new H1 regulations, the
construction R-value of the last
500mm of the perimeter of the ceiling
insulation can be reduced to R3.3,
meaning the insulation R-value can be
reduced to around R3.6 depending on
the amount of thermal bridging.
Skillion ceilings pose a unique
challenge for achieving the new higher
values, particularly via the Schedule
Method.
With rafters at 600mm centres or less, an R7.0
segment will not achieve the required R6.6
construction R-value. Therefore, Comfortech® has
developed a new R7.4 single-layer solution, suitable
for skillion roofs with 290mm rafter depths.
Adequate ventilation is critical to the performance
of ceiling insulation. As R values increase, the
temperature differential between the air below
and above the insulation also increases, therefore
increasing the likelihood of condensation
occurring when the warm air from below meets
the cold air above.
For rafters of less than 290mm depth, the
Comfortech® solution is to use the R 6.0 Skillion
Roof Pink® Batts® insulation with a second layer,
at 40mm thickness, of R1.0 Pink® Batts® installed
below the rafters, between the ceiling battens.
With the increase in insulation thickness required
to meet the 5th Edition of H1, Comfortech® also
identified a potential increased risk of the insulation
coming into contact with the underside of the roof
and underlay, preventing ventilation of the ceiling
space and creating a condensation and mould risk.
This system addresses the thermal bridging issue
and ensures the R6.6 construction can be achieved
even in a skillion roof situation. Additional over-eave
ventilation should also be considered, as the small
volume of airflow in skillion roofs increases the
condensation risk further.
Therefore, Comfortech® recommends installing an
insulation guard for both the single and doublelayer system, over the roof trusses and under the
roof underlay, before the roof is installed. The
insulation guard ensures the minimum 25mm air gap
is maintained even where the insulation is installed
under compression out to the roof edge, over the
top plate. This enables convective heat flow to
remove moisture from the roof space, preventing
condensation build, which would reduce the thermal
performance.
Contact Comfortech® for more solutions at
technicalsupport@comfortech.co.nz .
T
he new H1 Building Code changes only require
walls to hold a construction R-value of 2.0
nationwide. However, the BRANZ Beacon
Pathway report highlighted that the average amount of
framing in walls was 34%, rather than the previously
assumed 12 - 18%, raising an increased interest in
higher R-value products for walls.
PINK® BATTS® ULTRA®
Comfortech® is well prepared to help you with these changes. Our Pink® Batts®
ULTRA® insulation products – with an R-value of 2.6 and 2.8 for a 90mm wall,
or R3.2 to R4.3 for 140mm walls – ensure you can meet the required H1 5th Edition
Construction R-values.
WALL INSULATION
FROM 1 MAY 2023, WALLS IN HOUSING
ACROSS NEW ZEALAND WILL HAVE TO
MEET A MINIMUM CONSTRUCTION
R-VALUE OF R2.0.
Comfortech®
Double layer with
Insulation Guard
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Comfortech®
Skillion Ceiling
TUMU H1 GUIDE
*These solutions are the property of Comfortech, not Tumu Building Supplies
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