PDF | 1 MB - Australian Building Codes Board

REVIEW OF

THERMAL PERFORMANCE CRITERIA

IN THE BCA2009

FOR

ABCB

June 2009

Revision 3/6/2009

JAMES M FRICKER PTY LTD

54 Felix Crescent

Ringwood North VIC 3134

Mobile: 0414 804 097

Phone/Fax: (03) 9879 5744

fricker@optusnet.com.au

http://fricker.net.au

Report No:

File:292_RepA.doc

i292a

JAMES M FRICKER PTY LTD i150a ABCB

1. AIM

To

(a) Review R-Values in Specification J1

(b) Review of compensation for insulation lost through penetrations

(c) Development of an alternative to a thermal break

This work has been initiated by some changes introduced in Amdt 1 (Dec 2006) of AS/NZS 4859.1:2002

Materials for the thermal insulation of buildings - Part 1: General criteria and technical provisions.

The client for this work is **Australian** **Building** **Codes** **Board**, GPO Box 9839, Canberra ACT 2601, Phone: 02 6213

7291, Fax: 02 6290 8545, the contact being John Kennedy, email: John.Kennedy@abcb.gov.au.

2. REFERENCED DOCUMENTS

This review is based on the following documents emailed to the author:

"Trethowen report for walls.doc"

"Brief - Thermal break alternative 2010.doc"

"Brief - Spec J1 2 values 2010.doc"

"Brief Downlight compensation 2010.doc"

"BCA 2009 Volume Two assemblies.pdf"

"BCA 2009 Volume One Specs.pdf"

3. CALCULATIONS RESULTS PRESENTED

The comments and review are based on calculations per:

a) AS/NZS 4859.1:2002/Amdt 1 (Dec 2006) “Materials for the thermal insulation of buildings. Part 1: General

criteria and technical provisions”,

b) the **Australian** Institute of Refrigeration Air-conditioning & Heating (AIRAH) 2007 Handbook, and the ASHRAE

Fundamentals Handbook.

Thermal resistance results reported are for the insulation path only unless otherwise stated. (See clause on

Thermal Bridging. The BCA separately addresses thermal bridging at frames for specific constructions.)

Total R includes surface air film resistances.

R-values for parallel-faced air cavities were calculated using the Reflect-3 computer software that is based on

Robinson and Powell data and validated by Oakridge National Laboratory, USA. These calculations take input

from (and are affected by)

♦

♦

♦

♦

♦

the air gap (mm),

heat flow direction (because of convection effects),

in-situ infrared emittances* and

temperatures of the surfaces bounding the insulating air space

ventilation.

JAMES M FRICKER PTY LTD i150a ABCB

* Many have considered the revised dust assumptions of Amendment 1 (Dec 2006) as pessimistic, but the

fact is they are now accepted for labelling purposes. The changes mainly affect Total R calcs that have

upward-facing RFLs (reflective foil laminates).

Where applicable, the R-values of enclosed air spaces greater than 100mm were calculated per ISO 6946:2007

“**Building** components and building elements — Thermal resistance and thermal transmittance — Calculation

method”.

R-values are based on product in-service conditions including the alteration of insulation material R for

temperature introduced in Amdt 1. This mean airspace temperature is based on the particular construction and

the system bounding air temperatures for the **Australian** summer air temperature difference of 12K (36°C less

24°C), and winter air temperature difference of 6K (18°C less 12°C) set in Amdt 1. This has resulted in the

summer (heat flow in) Total R for walls being slightly less than for winter (heat flow out).

4. THERMAL BRIDGING

The original AS/NZS 4859.1:2002 clearly required reporting of the total thermal resistance for the insulation path

only. This Total R has many examples in prior editions of the BCA as well as in the 1985-2007 AIRAH

Handbooks.

Amendment 1 (Dec 2006) of AS/NZS 4859.1:2002 Clause 1.5.3.3 redefines Total R as "representative of the

element of construction”. For simplicity (the KISS principle), and to be consistent with earlier BCA releases, this

review assumes the “element of construction” is that which typifies the insulation path only.

The thermally bridged (full surface) Total R is normally very similar to the insulation path Total R for most

constructions. The main exceptions are high conductivity clad walls thermally coupled to metal frames without

thermal breaks (insulating spacers)

All calculations and study were done by:

JAMES M FRICKER

B.Mech E, M.AIRAH, M.EngAust, CPEng

PAPERS PUBLISHED:

Computational Analysis of Reflective Air Spaces, AIRAH Journal, Oct 1997

Low Energy Housing Design, UNESCO conference, Alice Springs 1990 (co-author with Angelo Delsante, CSIRO)

Calculation of Energy Targets, ASHRAE Journal, Oct 1987.

Testing and Modelling Flexible Air Duct Insulation Performance, 21 st International Conference on Thermal Insulation (co-author with Dr Peter

Johnson, RMIT)

(for BCA data of 30 May 2009) Page 2

JAMES M FRICKER PTY LTD i150a ABCB

5. REVIEW OF R-VALUES IN SPECIFICATION J1

The 2006 Amendment 1 now referenced caused the following:

(b) Revised dust assumptions that many find pessimistic but are now generally accepted for labelling purposes.

The changes mainly affect 2002 Total R calcs that have upward-facing RFLs (reflective foil laminates).

Preamble:

Most of the following changes are a result of changes in AS/NZS 4859.1:2002/Amdt 1 2006.

♦

♦

♦

♦

♦

♦

Calculation conditions are based on Climate Zone energy requirements (not maximum heating or cooling

load requirements), so calculations are not based on extreme air temperature differences, but the

standard **Australian** air temperature differences per AS/NZS 4859.1:2002/Amdt 1 2006 (winter: 18°-12°C

= 6K, summer: 36°-24°C = 12K).

Amendment 1 has revised the outdoor Air Film Resistance of R0.03 (7 m/s) to R0.04 (3m/s) for the same

reason. The extra 0.01 is insignificant so does not justify alteration of the Required Total R values now

referenced by many documents and legislation, but example Total R-calcs in the BCA should have the

0.04 and not the 0.03. Table insulation values should be adjusted so value additions maintain existing

“Minimum required Total R-Values”.

AS/NZS 4859.1:2002/Amdt 1 2006 introduces calculation for insulation R affected by insulation mean

temperature, hence Wall Total R values are slightly lower for summer than for winter for highly insulated

walls.

To retain simpler compliance, Total R calculations remain for the insulation path only in this review as

thermal bridging is discussed and considered elsewhere in the BCA.

Calculation of the thermal resistance of unventilated air spaces has been well established for parallel

faced air spaces up to 100mm apart. ISO 6946:2007 "**Building** components and building elements —

Thermal resistance and thermal transmittance — Calculation method" now enables calculation for spaces

greater than 100mm apart. It is recommended this standard be included as a reference as AS/NZS

4859.1 has not yet been updated to reference it.

Amdt 1 2006 introduces recognition of ground thermal resistance for enclosed subfloors, making it easier

to meet enclosed ground floor insulation requirements.

(for BCA data of 30 May 2009) Page 3

JAMES M FRICKER PTY LTD i150a ABCB

5.1 RECOMMENDATIONS

Refer "BCA 2009 VOLUME ONE SPECS.**PDF**"

Spec J1.2 – 2, Table 2b TYPICAL R-VALUES FOR AIRSPACES AND AIR FILMS

1. Airspaces non-reflective unventilated

"In any roof space with a horizontal ceiling, with a pitch more than 5°", Down should be R0.28, not R0.218 (typing

error).

Spec J1.2 – 2, Table 2c TYPICAL THERMAL PROPERTIES FOR REFLECTIVE SURFACES AND

AIRSPACES IN ROOFS

This table has needed some clarification, so I suggest renaming the heading to Table 2c ADDED R-VALUES

FOR REFLECTIVE INSULATION IN ROOF AIRSPACES

And adding the notes:

(i)

(ii)

"This table presumes the addition of the RBM adds a 20mm airspace between the RBM and roof

surface. The “outer emittance” is for the RBM face-up surface and the “inner emittance” is for the

face-down (dust-free) surface.” [Ed note: Thus the values are unaffected by the more severe dust

assumptions of AS/NZS 4859.1:2002/Amdt 1 2006]

“Where the RBM is a reflective bubble material or foam plastic, add its Material R-Value to the above

table values.”

Spec J1.3, Figure 2 TYPICAL R-VALUES FOR ROOF AND CEILING CONSTRUCTION &

Spec J1.5, Figure 2 TYPICAL R-VALUES FOR WALL CONSTRUCTION

Outdoor air film R0.03 (7 m/s) should be R0.04 (3m/s) per AS/NZS 4859.1:2002/Amdt 1 2006. Thus Roof and

Wall outdoor airfilm R values (summer and winter) are 0.01 higher.

For the same reason, Spec J1.5-2 Fig 2 Note 5 should be revised to:

"The Total R-Values in this Figure are for external walls. The Total R-Value for an internal wall of the

same construction would be 0.08 greater because the R-Value for an outdoor air film would be replaced

by that of an indoor air film."

Spec J1.6 Examples (b), (c), (d), Figure 2 TYPICAL R-VALUES FOR FLOOR CONSTRUCTION (for a floor

without a floor heating system)

As outdoor air film R0.03 (7 m/s) should be R0.04 (3m/s), raise Total R of ventilated subfloor example R-calcs by

0.01.

Replace Note 3 with

"3a. For floor types (b), (c) and (d) located over ground with enclosed perimeter, the Total R-Value can be

calculated by replacing the value for outdoor air film (R0.04) on the underside of the floor with the value

for indoor air film plus ground thermal resistance (i.e. R0.11+R0.56=R0.67 for heat flow up, or

R0.16+R0.58=R0.74 for heat flow down). The required heat flow direction is set by the Climate Zone.

3b. For floor types (c) and (d) that are located over an internal space, the Total R-Value can be calculated

by replacing the value for outdoor air film (R0.04) on the underside of the floor with the value for indoor air

film (R0.11 heat flow up, or R0.16 for heat flow down).

Add Note 7. “Where a RBM is attached beneath the floor to add a 100mm reflective air space, add R0.38 for heat

flow up and R1.14 for heat flow down.”

(for BCA data of 30 May 2009) Page 4

JAMES M FRICKER PTY LTD i150a ABCB

Add Note 8. "Where ground floor construction with enclosed perimeter makes the air space adjacent ground

reflective, the face-down subfloor air films will be R0.23 instead of R0.11 heat flow up, and R0.80 instead of R0.16

for heat flow down."

Refer "BCA 2009 VOLUME TWO ASSE**MB**LIES.**PDF**"

Figure 3.12.1.1 TYPICAL INSULATION OPTIONS FOR TYPICAL ROOF AND CEILING CONSTRUCTION, (a)

and (b) on page 433:

“Total R-Value of roof and ceiling materials” should be renamed to “Total R-Value of uninsulated roof”.

“Minimum required Total R values” should remain unchanged, thus all “Minimum added R-values of

insulation” should decrease by 0.04-0.03=0.01 due to the changed outdoor air film assumption.

Thus Tiled Roof Total R-Values (across the table) should be 0.44, 0.38, and 0.38 and metal Roof Total R-

Values should be 0.42, 0.36, and 0.36

and for (c) on page 434

Tiled Roof Total R-Values (across the table) should be 0.74, 0.23, and 0.23 and Metal Roof Total R-

Values should be 0.72, 0.21, and 0.21

and for (d) on page 435

Tiled Roof Total R-Values should be 0.56, 0.41, and 0.41 and Metal Roof Total R-Values should be 0.54,

0.39, and 0.39 (Again, Added R-values should remain unchanged.)

Likewise for Figure 3.12.1.3 TYPICAL INSULATION OPTIONS FOR TYPICAL WALL CONSTRUCTION, (a)

and (b) on page 433:

“Total R-Value of wall materials” should be renamed to “Total R-Value of uninsulated wall”.

“Minimum required Total R values” should remain unchanged, thus all “Minimum added R-values of

insulation” should decrease by 0.04-0.03=0.01 due to the changed outdoor air film assumption.

Also, (a) to (h) “Total R-Value of wall materials” should be renamed to “Total R-Value of uninsulated wall”

e.g. (a) Weatherboard, “Total R-Value of uninsulated wall” should be 0.48, not 0.47, hence “Minimum

added R-Value of insulation” should be 1.42, not 1.43, etc.

Likewise for the Total R-Values (b) to (h) and Added R-Values.

On Page 447, Explanatory Information (really Notes), add

3. “Insulation R depends on temperature, so Wall Total R-Values are now calculated per AS/NZS

4859.1:2002/Amdt 1 2006 for summer, winter or both according to the climate zone. The direction of heat

flow is not stated as it is given for roofs with downwards in summer for roofs being inwards for walls and

upwards in winter for roofs being outwards for walls. However, for the example systems given, the

summer and winter Total R-values are similar, and, for simplicity, remain valid."

(for BCA data of 30 May 2009) Page 5

JAMES M FRICKER PTY LTD i150a ABCB

Spec 3.12.1.5 FLOORS, page 449, 450

As AS/NZS 4859.1:2002/Amdt 1 2006 appropriately recognises and introduces Ground Thermal Resistance for

ground floors above an unventilated space, related Table 3.12.1.4 Minimum Total R-Values are more easily met.

Figure 3.12.1.4:

“Total R-Value of floor materials” should be renamed to “Total R-Value of uninsulated floor”. For (a) “Suspended

Timber Floor”, the value should not be just 0.7 but 1.3 for enclosed, and remain 0.7 for unenclosed.

The "Minimum required Total R-Values" remain unchanged, but because ground thermal resistance assists with

enclosed subfloor resistance (by R0.56 heat flow up, R0.58 for heat flow down), the (a) “Enclosed” “Suspended

Timber Floor” “Minimum R-Values of insulation” (0.3, 0.3, 0.8, 1.3) become 0, 0, 0.2, 0.7. (The “Unenclosed”

remain unchanged.)

Similarly for (b) “Suspended Concrete Slab”, “Total R-Value of floor materials” should be renamed to “Total R-

Value of uninsulated floor” and the value should not be just 0.65 but 1.2 for enclosed, and remain 0.65 for

unenclosed; and the “Minimum R-Values of insulation” (0.35, 0.35, 0.85) become 0, 0, 0.27. (The “Unenclosed”

remain unchanged.)

For "Explanatory information"

To note 2, add "Typically, where a RBM is attached beneath the floor to add a 100mm reflective air

space, add R0.38 for heat flow up and R1.14 for heat flow down. The required heat flow direction is set

by the Climate Zone."

Add note 5, "For floors located over ground with enclosed perimeter, the Total R-Value can be calculated

by replacing the value for outdoor air film (R0.04) on the underside of the floor with the value for indoor air

film plus ground thermal resistance (i.e. R0.11+R0.56=R0.67 for heat flow up, or R0.16+R0.58=R0.74 for

heat flow down).

For floors located over an internal space, the Total R-Value can be calculated by replacing the value for

outdoor air film (R0.04) on the underside of the unenclosed floor with the value for indoor air film (R0.11

heat flow up, or R0.16 for heat flow down)."

Add Note 6. "Where ground floor construction with enclosed perimeter makes the air space adjacent

ground reflective, the subfloor air films will be R0.23 instead of R0.11 heat flow up, and R0.80 instead of

R0.16 for heat flow down."

Add Note 7. “Where a RBM is attached beneath the floor to add a 100mm reflective air space, add R0.38

for heat flow up and R1.14 for heat flow down.”

Add Note 8. "For ground floor construction with enclosed perimeter, if the floor downward surface is

reflective, its air film will be R0.23 instead of R0.11 heat flow up, and R0.80 instead of R0.16 for heat flow

down."

(for BCA data of 30 May 2009) Page 6

JAMES M FRICKER PTY LTD i150a ABCB

6. REVIEW OF COMPENSATION FOR INSULATION LOST THROUGH PENETRATIONS

Background: The current Clause 2.12.1.2(c) requires additional insulation in a roof where there are penetrations

such as downlights and fans and the amounts are in Table 3.12.1.1 however its use is limited as it is in terms of

the climate zone requirements.

6.1 RECOMMENDATIONS

Refer " BRIEF DOWNLIGHT COMPENSATION 2010.DOC"

Replace Table 3.12.1.1a ADJUSTMENT OF MINIMUM R-VALUE FOR A REDUCTION OF CEILING

INSULATION with the alternative table that is independent of the climate zone:

Percentage of ceiling

without insulation

Adjusted minimum added ceiling insulation

0.00% R2.5 R3.0 R3.5 R4.0 R4.5 R5.0 R5.5 R6.0 R6.5 R7.0

up to 0.25% R2.6 R3.1 R3.6 R4.2 R4.7 R5.2 R5.8 R6.4 R6.9 R7.5

up to 0.50% R2.6 R3.2 R3.8 R4.3 R4.9 R5.5 R6.1 R6.8 R7.4 R8.1

up to 0.75% R2.7 R3.3 R3.9 R4.5 R5.2 R5.8 R6.5 R7.2 R7.9 R8.7

up to 1.00% R2.8 R3.4 R4.0 R4.7 R5.4 R6.2 R6.9 R7.7 R8.6 R9.5

up to 1.25% R2.9 R3.5 R4.2 R4.9 R5.7 R6.5 R7.4 R8.3 R9.3

up to 1.50% R2.9 R3.6 R4.4 R5.2 R6.1 R7.0 R8.0 R9.1

up to 2.00% R3.1 R3.9 R4.8 R5.8 R6.8 R8.0 R9.4

up to 2.50% R3.3 R4.2 R5.3 R6.5 R7.9 R9.5

up to 3.00% R3.6 R4.6 R5.9 R7.4 R9.3

up to 4.00% R4.2 R5.7 R7.6

up to 5.00% R5.0 R7.3 Compensatory insulation not applicable

up to 6.00% R6.2

NOTES:

(i)

(ii)

(iii)

The above table shows what Added Ceiling Insulation is required to compensate for exposed ceiling

to provide equal thermal performance. These are applicable unless the cut-out has its own insulation,

e.g. downlight enclosure, or other insulation.

Assumes where there is no insulation, there is bare 10mm plasterboard and lamp has negligible R or

portion of insulation area is cut-out.

The above table is not an endorsement for high insulation, but the consequence of significant

uninsulated ceiling area. It is not intended as the solution to missing or removed insulation, but the

incentive for alternatives such as fewer downlights or heat shields to allow insulation to abut

downlights.

[JMF calculation assumptions: Extra R for insulation path: 0.279 (10mm plasterboard with 2 x R0.11 air films).

Base R for path without insulation: 0.279 (10mm plasterboard with 2 x R0.11 air films). Calculated by Isothermal

Planes method after including the thermal resistances of 10mm plasterboard and R0.11 air films.]

(for BCA data of 30 May 2009) Page 7

JAMES M FRICKER PTY LTD i150a ABCB

7. STUDY OF ALTERNATIVES TO A THERMAL BREAK

Background: The BCA Volumes 1 & 2 building fabric provisions contain requirements for Total R-Value of roofs,

walls and floors. These Total R-Values are based on timber framing and include an allowance for thermal

bridging of the insulation by the timber frame. In 2006, a requirement was added for a thermal break to be

attached to a metal frame in certain circumstances. This was in order for a metal famed building to have

comparable thermal performance to that of a timber framed one.

The BCA Clause states:

"A wall that—

(i) is required to achieve a minimum Total R-Value; and

(ii) has lightweight external cladding such as weatherboards, fibre cement or metal sheeting fixed to the

metal frame; and

(iii) does not have a wall lining or has a wall lining that is fixed directly to the metal frame (see Figure

3.12.1.3(a) and (b)),

must have a thermal break, consisting of a material with an R-Value of not less than 0.2, installed between

the external cladding and the metal frame."

This study is to assess the option of compensatory insulation as an alternative option to the R0.2 thermal break

for metal-framed walls.

7.1 RECOMMENDATIONS

Refer "APPENDIX 1 – CLAD WALLS & THERMAL BREAKS" for illustrative calculations.

Recommendation: Replace

With

“must have a thermal break, consisting of a material with an R-Value of not less than 0.2, installed between

the external cladding and the metal frame."

“must have

(i)

(ii)

(iii)

a thermal break consisting of a material with an R-Value of not less than 0.2, installed between the

external cladding and the metal frame OR

50% more added insulation to compensate for thermal bridging OR

a suitably proven alternative to minimise thermal bridging, such as significant reduction of bridging

area by standoff washers or other spacers at fixing points "

(for BCA data of 30 May 2009) Page 8

JAMES M FRICKER PTY LTD i150a ABCB

APPENDIX 1 – CLAD WALLS & THERMAL BREAKS

Please refer following pages of spreadsheet calculations.

(for BCA data of 30 May 2009) Page 9

JAMES M FRICKER PTY LTD Report i150b **Australian** **Building** **Codes** **Board**

Total R

JMF insulation Total Total R

Calc. CLAD WALLS & THERMAL BREAKS path overall loss

150.11b CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R1.8 BULK INSULATION & R2.04 R1.66 19%

PLASTERBOARD (70MM METAL STUD ON 450MM CENTRES)

(Base case: Bulk insulation not overlapping frame. R0.2 thermal break.)

150.12b CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R1.8 BULK INSULATION & R2.04 R1.37 33%

PLASTERBOARD (70MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal break.)

Comparing this with JMF 150.11b, it is evident that the lack of an R0.2 thermal break has

reduced overall Total R from R1.66 to R1.37.

150.13b CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R2.65 BULK INSULATION & R2.89 R1.66 43%

PLASTERBOARD (70MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal break.)

Comparing this with JMF 150.11b, it is evident that R1.8 bulk insulation must be replaced with

R2.65 insulation if there is no R0.2 thermal break. (There may not be room for this level of bulk

insulation.)

150.14b CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R1.5 BULK INSULATION & R1.74 R1.67 4%

PLASTERBOARD (70MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal break but steel washers used as flange

standoffs.)

Comparing this with JMF 150.11b, with reduced thermal bridging area, R1.5 bulk insulation can

replace R1.8 insulation for the same overall Total R. (And without an R0.2 thermal break.)

(Steel stud flanges not connecting to cladding except via washer standoffs.)

150.111b CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R2.72 BULK INSULATION & R2.96 R2.20 26%

PLASTERBOARD (100MM METAL STUD ON 450MM CENTRES)

(Base case: Bulk insulation not overlapping frame. R0.2 thermal break.)

2nd reference case having R0.2 Thermal Break.

150.121b CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R2.72 BULK INSULATION & R2.96 R1.80 39%

PLASTERBOARD (100MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal break.)

Comparing this with JMF 150.111b, it is evident that the lack of an R0.2 thermal break has

reduced overall Total R from R2.2 to R1.8.

150.131b CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R4.22 BULK INSULATION & R4.46 R2.20 51%

PLASTERBOARD (100MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal break.)

Comparing this with JMF 150.111b, it is evident that R2.72 bulk insulation must be replaced

with R4.22 insulation if there is no R0.2 thermal break. (There may not be room for this level of

bulk insulation.)

150.141b CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R2.1 BULK INSULATION & R2.31 R2.20 5%

PLASTERBOARD (100MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal break but steel washers used as flange

standoffs.)

Comparing this with JMF 150.111b, with reduced thermal bridging area, R2.1 bulk insulation

can replace R2.2 insulation for the same overall Total R. (And without an R0.2 thermal break.)

(Steel stud flanges not connecting to cladding except via washer standoffs.)

NOTES:

The above shows Total R determinations based upon AS/NZS 4859.1:2002/Amdt 1 2006, Materials for the thermal

insulation of buildings.

See individual calculations for further commentary.

Results current as at 30/04/2009

JAMES M FRICKER PTY LTD Report i150b **Australian** **Building** **Codes** **Board**

JMF Calc 150.11b

CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R1.8 BULK

INSULATION & PLASTERBOARD (70MM METAL STUD ON 450MM CENTRES)

(Base case: Bulk insulation not overlapping frame. R0.2 thermal break.)

No thermal break

Insul Frame

Path area ratio:

415

92.2%

35

7.8%

Thermal resistances (m².K/W):

Outside Air Film, cement sheet

cladding: 0.064

Vapour Permeable Sarking

Thermal break R:

Metal stud

0.000 0.000

0.200

0.149

Bulk Insulation

1.800

10mm Plasterboard

Indoor air film

0.059

0.120

Path Total R: 2.043 0.592 a

R by Parallel Path Method:

R by Isothermal Planes Method:

Total R:

1.716

1.603

1.66 b

% Reduction by thermal bridging: 19% c

NOTES:

Revision: 29/04/2009 9:33 PM

The above estimates the resulting insulation value from the two parallel heat paths

- through cladding, cavity, sarking, then insulation and internal wall lining,

- through cladding, batten, then metal "C" frame and internal wall lining.

Total R calculations based on AS/NZS 4859.1:2002/Amdt 1 2006.

Cladding and plasterboard assumed to be relevant isothermal planes.

Stud: framing of 0.55mm steel (k=50W/m.K), flanges 35mm, web 70mm, 450mm centres.

METHOD OF CALCULATION OF METAL FRAME "Re" (EQUIVALENT R):

Transforming the frame into equivalent rectangular shapes per Equation 9, NZ Standard NZ 4214 2006:

Re=(flange width/web thickness)•(web depth/conductivity)+contact resistance

- the resistance of the steel Stud frame is Re = 0.149 m².K/W

The Total R is calculated by the average of results from Parallel Path Method and Isothermal Planes Method per CSIRO advice.

The %Reduction is calculated by c=(a-b)/a•100%

A more accurate result may require full scale testing or rigorous Finite Element Analysis.

Signed:

Reference case having R0.2 Thermal Break.

JAMES M FRICKER

B Mech Eng, CPEng, M.AIRAH

JAMES M FRICKER PTY LTD Report i150b **Australian** **Building** **Codes** **Board**

JMF Calc 150.12b

CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R1.8 BULK

INSULATION & PLASTERBOARD (70MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal break.)

No thermal break

Insul Frame

Path area ratio:

415

92.2%

35

7.8%

Thermal resistances (m².K/W):

Outside Air Film, cement sheet

cladding: 0.064

Vapour Permeable Sarking

No thermal break:

Metal stud

0.000 0.000

0.000

0.149

Bulk Insulation

1.800

10mm Plasterboard

Indoor air film

0.059

0.120

Path Total R: 2.043 0.392 a

R by Parallel Path Method:

R by Isothermal Planes Method:

Total R:

1.539

1.210

1.37 b

% Reduction by thermal bridging: 33% c

NOTES:

Revision: 29/04/2009 9:33 PM

The above estimates the resulting insulation value from the two parallel heat paths

- through cladding, cavity, sarking, then insulation and internal wall lining,

- through cladding, batten, then metal "C" frame and internal wall lining.

Total R calculations based on AS/NZS 4859.1:2002/Amdt 1 2006.

Cladding and plasterboard assumed to be relevant isothermal planes.

Stud: framing of 0.55mm steel (k=50W/m.K), flanges 35mm, web 70mm, 450mm centres.

METHOD OF CALCULATION OF METAL FRAME "Re" (EQUIVALENT R):

Transforming the frame into equivalent rectangular shapes per Equation 9, NZ Standard NZ 4214 2006:

Re=(flange width/web thickness)•(web depth/conductivity)+contact resistance

- the resistance of the steel Stud frame is Re = 0.149 m².K/W

The Total R is calculated by the average of results from Parallel Path Method and Isothermal Planes Method per CSIRO advice.

The %Reduction is calculated by c=(a-b)/a•100%

A more accurate result may require full scale testing or rigorous Finite Element Analysis.

Signed:

Comparing this with JMF 150.11b, it is evident that the lack of an R0.2 thermal break

has reduced overall Total R from R1.66 to R1.37.

JAMES M FRICKER

B Mech Eng, CPEng, M.AIRAH

JAMES M FRICKER PTY LTD Report i150b **Australian** **Building** **Codes** **Board**

JMF Calc 150.13b

CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R2.65 BULK

INSULATION & PLASTERBOARD (70MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal break.)

No thermal break

Insul Frame

Path area ratio:

415

92.2%

35

7.8%

Thermal resistances (m².K/W):

Outside Air Film, cement sheet

cladding: 0.064

Vapour Permeable Sarking

No thermal break:

Metal stud

0.000 0.000

0.000

0.149

Bulk Insulation

2.650

10mm Plasterboard

Indoor air film

0.059

0.120

Path Total R: 2.893 0.392 a

R by Parallel Path Method:

R by Isothermal Planes Method:

Total R:

1.934

1.393

1.66 b

% Reduction by thermal bridging: 43% c

NOTES:

Revision: 29/04/2009 9:33 PM

The above estimates the resulting insulation value from the two parallel heat paths

- through cladding, cavity, sarking, then insulation and internal wall lining,

- through cladding, batten, then metal "C" frame and internal wall lining.

Total R calculations based on AS/NZS 4859.1:2002/Amdt 1 2006.

Cladding and plasterboard assumed to be relevant isothermal planes.

Stud: framing of 0.55mm steel (k=50W/m.K), flanges 35mm, web 70mm, 450mm centres.

METHOD OF CALCULATION OF METAL FRAME "Re" (EQUIVALENT R):

Transforming the frame into equivalent rectangular shapes per Equation 9, NZ Standard NZ 4214 2006:

Re=(flange width/web thickness)•(web depth/conductivity)+contact resistance

- the resistance of the steel Stud frame is Re = 0.149 m².K/W

The Total R is calculated by the average of results from Parallel Path Method and Isothermal Planes Method per CSIRO advice.

The %Reduction is calculated by c=(a-b)/a•100%

A more accurate result may require full scale testing or rigorous Finite Element Analysis.

Signed:

Comparing this with JMF 150.11b, it is evident that R1.8 bulk insulation must be

replaced with R2.65 insulation if there is no R0.2 thermal break.

(There may not be room for this level of bulk insulation.)

JAMES M FRICKER

B Mech Eng, CPEng, M.AIRAH

JAMES M FRICKER PTY LTD Report i150b **Australian** **Building** **Codes** **Board**

JMF Calc 150.14b

CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R1.5 BULK

INSULATION & PLASTERBOARD (70MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal

break but steel washers used as flange standoffs.)

No thermal break

Insul Frame

415 35

Path area ratio after flanges

offset by steel washers: 99.2% 0.8%

Thermal resistances (m².K/W):

Outside Air Film, cement sheet

cladding: 0.064

Vapour Permeable Sarking

No thermal break:

Metal stud

Bulk Insulation

0.000

1.500

0.000

0.000

0.149

10mm Plasterboard

Indoor air film

0.059

0.120

Path Total R: 1.743 0.392

R by Parallel Path Method: 1.698

R by Isothermal Planes Method: 1.644

Total R: 1.67

% Reduction by thermal bridging: 4%

a

b

c

NOTES:

Revision: 29/04/2009 9:33 PM

The above estimates the resulting insulation value from the two parallel heat paths

- through cladding, cavity, sarking, then insulation and internal wall lining,

- through cladding, batten, then metal "C" frame and internal wall lining.

Total R calculations based on AS/NZS 4859.1:2002/Amdt 1 2006.

Cladding and plasterboard assumed to be relevant isothermal planes.

Stud: framing of 0.55mm steel (k=50W/m.K), flanges 35mm, web 70mm, 450mm centres.

METHOD OF CALCULATION OF METAL FRAME "Re" (EQUIVALENT R):

Transforming the frame into equivalent rectangular shapes per Equation 9, NZ Standard NZ 4214 2006:

Re=(flange width/web thickness)•(web depth/conductivity)+contact resistance

- the resistance of the steel Stud frame is Re = 0.149 m².K/W

The %Reduction is calculated by c=(a-b)/a•100%

A more accurate result may require full scale testing or rigorous Finite Element Analysis.

Signed:

Comparing this with JMF 150.11b, with reduced thermal bridging area, R1.5 bulk

insulation can replace R1.8 insulation for the same overall Total R.

(And without an R0.2 thermal break.)

(Steel stud flanges not connecting to cladding except via washer standoffs.)

JAMES M FRICKER

B Mech Eng, CPEng, M.AIRAH

JAMES M FRICKER PTY LTD Report i150b **Australian** **Building** **Codes** **Board**

JMF Calc 150.111b

CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R2.72 BULK

INSULATION & PLASTERBOARD (100MM METAL STUD ON 450MM CENTRES)

(Base case: Bulk insulation not overlapping frame. R0.2 thermal break.)

No thermal break

Insul Frame

Path area ratio:

415

92.2%

35

7.8%

Thermal resistances (m².K/W):

Outside Air Film, cement sheet

cladding: 0.064

Vapour Permeable Sarking

Thermal break R:

Metal stud

0.000 0.000

0.200

0.187

Bulk Insulation

2.720

10mm Plasterboard

Indoor air film

0.059

0.120

Path Total R: 2.963 0.630 a

R by Parallel Path Method:

R by Isothermal Planes Method:

Total R:

2.301

2.095

2.20 b

% Reduction by thermal bridging: 26% c

NOTES:

Revision: 30/04/2009 3:33 PM

The above estimates the resulting insulation value from the two parallel heat paths

- through cladding, cavity, sarking, then insulation and internal wall lining,

- through cladding, batten, then metal "C" frame and internal wall lining.

Total R calculations based on AS/NZS 4859.1:2002/Amdt 1 2006.

Cladding and plasterboard assumed to be relevant isothermal planes.

Stud: framing of 0.55mm steel (k=50W/m.K), flanges 35mm, web 100mm, 450mm centres.

METHOD OF CALCULATION OF METAL FRAME "Re" (EQUIVALENT R):

Transforming the frame into equivalent rectangular shapes per Equation 9, NZ Standard NZ 4214 2006:

Re=(flange width/web thickness)•(web depth/conductivity)+contact resistance

- the resistance of the steel Stud frame is Re = 0.187 m².K/W

The %Reduction is calculated by c=(a-b)/a•100%

A more accurate result may require full scale testing or rigorous Finite Element Analysis.

Signed:

2nd reference case having R0.2 Thermal Break.

JAMES M FRICKER

B Mech Eng, CPEng, M.AIRAH

JAMES M FRICKER PTY LTD Report i150b **Australian** **Building** **Codes** **Board**

JMF Calc 150.121b

CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R2.72 BULK

INSULATION & PLASTERBOARD (100MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal break.)

No thermal break

Insul Frame

Path area ratio:

415

92.2%

35

7.8%

Thermal resistances (m².K/W):

Outside Air Film, cement sheet

cladding: 0.064

Vapour Permeable Sarking

No thermal break:

Metal stud

0.000 0.000

0.000

0.187

Bulk Insulation

2.720

10mm Plasterboard

Indoor air film

0.059

0.120

Path Total R: 2.963 0.430 a

R by Parallel Path Method:

R by Isothermal Planes Method:

Total R:

2.032

1.569

1.80 b

% Reduction by thermal bridging: 39% c

NOTES:

Revision: 30/04/2009 3:33 PM

The above estimates the resulting insulation value from the two parallel heat paths

- through cladding, cavity, sarking, then insulation and internal wall lining,

- through cladding, batten, then metal "C" frame and internal wall lining.

Total R calculations based on AS/NZS 4859.1:2002/Amdt 1 2006.

Cladding and plasterboard assumed to be relevant isothermal planes.

Stud: framing of 0.55mm steel (k=50W/m.K), flanges 35mm, web 100mm, 450mm centres.

METHOD OF CALCULATION OF METAL FRAME "Re" (EQUIVALENT R):

Transforming the frame into equivalent rectangular shapes per Equation 9, NZ Standard NZ 4214 2006:

Re=(flange width/web thickness)•(web depth/conductivity)+contact resistance

- the resistance of the steel Stud frame is Re = 0.187 m².K/W

The %Reduction is calculated by c=(a-b)/a•100%

A more accurate result may require full scale testing or rigorous Finite Element Analysis.

Signed:

Comparing this with JMF 150.111b, it is evident that the lack of an R0.2 thermal break

has reduced overall Total R from R2.2 to R1.8.

JAMES M FRICKER

B Mech Eng, CPEng, M.AIRAH

JAMES M FRICKER PTY LTD Report i150b **Australian** **Building** **Codes** **Board**

JMF Calc 150.131b

CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R4.22 BULK

INSULATION & PLASTERBOARD (100MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal break.)

No thermal break

Insul Frame

Path area ratio:

415

92.2%

35

7.8%

Thermal resistances (m².K/W):

Outside Air Film, cement sheet

cladding: 0.064

Vapour Permeable Sarking

No thermal break:

Metal stud

0.000 0.000

0.000

0.187

Bulk Insulation

4.215

10mm Plasterboard

Indoor air film

0.059

0.120

Path Total R: 4.458 0.430 a

R by Parallel Path Method:

R by Isothermal Planes Method:

Total R:

2.580

1.820

2.20 b

% Reduction by thermal bridging: 51% c

NOTES:

Revision: 30/04/2009 3:33 PM

The above estimates the resulting insulation value from the two parallel heat paths

- through cladding, cavity, sarking, then insulation and internal wall lining,

- through cladding, batten, then metal "C" frame and internal wall lining.

Total R calculations based on AS/NZS 4859.1:2002/Amdt 1 2006.

Cladding and plasterboard assumed to be relevant isothermal planes.

Stud: framing of 0.55mm steel (k=50W/m.K), flanges 35mm, web 100mm, 450mm centres.

METHOD OF CALCULATION OF METAL FRAME "Re" (EQUIVALENT R):

Transforming the frame into equivalent rectangular shapes per Equation 9, NZ Standard NZ 4214 2006:

Re=(flange width/web thickness)•(web depth/conductivity)+contact resistance

- the resistance of the steel Stud frame is Re = 0.187 m².K/W

The %Reduction is calculated by c=(a-b)/a•100%

A more accurate result may require full scale testing or rigorous Finite Element Analysis.

Signed:

Comparing this with JMF 150.111b, it is evident that R2.72 bulk insulation must be

replaced with R4.22 insulation if there is no R0.2 thermal break.

(There may not be room for this level of bulk insulation.)

JAMES M FRICKER

B Mech Eng, CPEng, M.AIRAH

JAMES M FRICKER PTY LTD Report i150b **Australian** **Building** **Codes** **Board**

JMF Calc 150.141b

CEMENT SHEET CLADDING, VPS ON METAL FRAME WITH R2.1 BULK

INSULATION & PLASTERBOARD (100MM METAL STUD ON 450MM CENTRES)

(Bulk insulation not overlapping frame. No thermal

break but steel washers used as flange standoffs.)

No thermal break

Insul Frame

415 35

Path area ratio after flanges

offset by steel washers: 99.2% 0.8%

Thermal resistances (m².K/W):

Outside Air Film, cement sheet

cladding: 0.064

Vapour Permeable Sarking

No thermal break:

Metal stud

Bulk Insulation

0.000

2.070

0.000

0.000

0.187

10mm Plasterboard

Indoor air film

0.059

0.120

Path Total R: 2.313 0.430

R by Parallel Path Method: 2.237

R by Isothermal Planes Method: 2.163

Total R: 2.20

% Reduction by thermal bridging: 5%

a

b

c

NOTES:

Revision: 30/04/2009 3:33 PM

The above estimates the resulting insulation value from the two parallel heat paths

- through cladding, cavity, sarking, then insulation and internal wall lining,

- through cladding, batten, then metal "C" frame and internal wall lining.

Total R calculations based on AS/NZS 4859.1:2002/Amdt 1 2006.

Cladding and plasterboard assumed to be relevant isothermal planes.

Stud: framing of 0.55mm steel (k=50W/m.K), flanges 35mm, web 100mm, 450mm centres.

METHOD OF CALCULATION OF METAL FRAME "Re" (EQUIVALENT R):

Transforming the frame into equivalent rectangular shapes per Equation 9, NZ Standard NZ 4214 2006:

Re=(flange width/web thickness)•(web depth/conductivity)+contact resistance

- the resistance of the steel Stud frame is Re = 0.187 m².K/W

The %Reduction is calculated by c=(a-b)/a•100%

A more accurate result may require full scale testing or rigorous Finite Element Analysis.

Signed:

Comparing this with JMF 150.111b, with reduced thermal bridging area, R2.1 bulk

insulation can replace R2.2 insulation for the same overall Total R.

(And without an R0.2 thermal break.)

(Steel stud flanges not connecting to cladding except via washer standoffs.)

JAMES M FRICKER

B Mech Eng, CPEng, M.AIRAH

JAMES M FRICKER PTY LTD i150a ABCB

APPENDIX 2 – KEY PAGES OF EXISTING BCA 2009 FOR REFERENCE

Please refer following pages

(for BCA data of 30 May 2009)

Main Menu

ENERGY EFFICIENCY

SPECIFICATION J1.2

MATERIAL PROPERTIES

Deemed-to-Satisfy Provisions

1. Scope

This Specification lists the thermal properties of some common construction materials.

2. Construction Deemed-to-Satisfy

(a)

Table 2a lists the thermal conductivity considered to be achieved by some common

construction materials.

Table 2a THERMAL CONDUCTIVITY OF TYPICAL WALL, ROOF/CEILING AND FLOOR

MATERIALS

Material description

Material

density

kg/m 3

Thermal

conductivity

W/m.K

1. Framing

(a) Steel 7850 47.5

(b) Timber – kiln dried hardwood (across the grain) 677 0.16

(c) Timber – Radiata pine (across the grain) 506 0.10

2. Roof Cladding

(a) Aluminium sheeting 2680 210

(b) Concrete or terra cotta tiles 1922 0.81

(c) Steel sheeting 7850 47.5

3. Wall Cladding

(a) Aluminium sheeting 2680 210

(b) Autoclaved aerated concrete 350 0.10

900 0.27

(c) Cement render (1 cement : 4 sand) 1570 0.53

(d) Clay bricks

(i) Clay brick – 2.75 kg 1430 0.55

(ii) Clay brick – 3.25 kg 1690 0.65

(iii) Clay brick – 3.75 kg 1950 0.78

(e) Concrete blocks

(i) 190 mm dense or 90 mm dense solid 1100/2200 1.1

(ii) 140 mm dense or 190 mm lightweight 1250/910 0.85

(iii) 90 mm dense hollow or 90 mm lightweight solid 1650/1800 0.75

BCA 2009 Volume One **Australian** **Building** **Codes** **Board** Page 425

Main Menu

ENERGY EFFICIENCY

Spec J1.2 – 2.

Deemed-to-Satisfy Provisions

Table 2a THERMAL CONDUCTIVITY OF TYPICAL WALL, ROOF/CEILING AND FLOOR MATERIALS— continued

Material description

Material

density

kg/m 3

Thermal

conductivity

W/m.K

(iv) 140 mm lightweight 1050 0.67

(v) 90 mm lightweight 1360 0.55

(f) Fibre-cement 1360 0.25

(g) Gypsum plasterboard 880 0.17

(h) Pine weatherboards 506 0.10

(i) Plywood 530 0.14

(j) Solid concrete 2400 1.44

(k) Steel sheeting 7850 47.5

(l) Prestressed hollow core concrete panel 1680 0.80

4. Flooring Materials

(a) Carpet underlay - 0.04

(b) Carpet - 0.05

(c) Prestressed hollow core concrete planks 1680 0.80

(d) Particleboard 640 0.12

(e) Plywood 530 0.14

(f) Timber – kiln dried hardwood (across the grain) 677 0.16

(g) Timber – Radiata pine (across the grain) 506 0.10

(h) Solid concrete 2400 1.44

(i) Vinyl floor tiles 2050 0.79

5. Other Materials

(a) Air (still) 1.2 0.03

(b) Clay soil (10% moisture content) 1300 0.6

(c) PMMA (polymethylmethacrylate) 1180 1.00

(d) Polycarbonates 1200 0.2

(e) Sand (6% moisture content) 1800 1.64

(f) Soda lime glass 2500 1.0

Notes:

1. For materials which incorporate cores or hollows in regular patterns (such as cored

brickwork, hollow blockwork and cored floor or wall panels), the tabulated material

densities and thermal conductivities are based on the gross density (mass divided by

external dimensions).

2. The R-Value of a material is determined by dividing the thickness of the material in

metres by the thermal conductivity in W/m.K.

BCA 2009 Volume One **Australian** **Building** **Codes** **Board** Page 426

Main Menu

ENERGY EFFICIENCY

Spec J1.2 – 2.

(b)

Deemed-to-Satisfy Provisions

Table 2b lists the R-Values considered to be achieved by air films and airspaces.

Table 2b TYPICAL R-VALUES FOR AIRSPACES AND AIR FILMS

Position of air space

1. Airspaces non-reflective unventilated

Direction of

heat flow

R-Value

In a roof with a pitch of not more than 5 0 Up 0.15

Down 0.22

In a roof with a ceiling that is parallel with a roof with a Up 0.15

pitch more than 5 0 and not more than 15 0

Down 0.21

In a roof with a ceiling that is parallel with a roof with a Up 0.15

pitch more than 22 0 and not more than 45 0

Down 0.18

In any roof space with a horizontal ceiling, with a pitch Up 0.18

more than 5 0

Down 0.218

In a wall Horizontal 0.17

2. Airspaces non-reflective ventilated

In any roof with a pitch not more than 5 0 and 100 mm

deep air space

Up

Nil

Down 0.19

In any roof space with a horizontal ceiling, with a pitch Up Nil

more than 5 0

Down 0.46

In a wall Horizontal 0.14

3. Air films – Still air

On a surface with a pitch of not more than 5 0 Up 0.11

Down 0.16

On a surface with a pitch of more than 5 0 and not more Up 0.11

than 30 0

On a surface with a pitch of more than 30 0 and not more

than 45 0

45° slope

Down 0.15

Up 0.11

Down 0.13

On a wall Horizontal 0.12

4. Air films – Moving air

Not more than 3 m/s wind Any direction 0.04

BCA 2009 Volume One **Australian** **Building** **Codes** **Board** Page 427

Main Menu

ENERGY EFFICIENCY

Spec J1.2 – 2.

Deemed-to-Satisfy Provisions

Table 2b TYPICAL R-VALUES FOR AIRSPACES AND AIR FILMS— continued

Position of air space

More than 3 m/s wind speed and not more than 7 m/s

wind speed

Direction of

heat flow

R-Value

Any direction 0.03

Note:

R-Values are for a temperature of 10°C and temperature difference of 15K.

(c)

The thermal properties considered to be achieved by reflective surfaces are—

(i) within a wall—

(A) with an inner reflective surface of 0.05 emittance and a 20 mm airspace to

the wall lining, an added R-Value of 0.48; and

(B) with an inner reflective surface of 0.05 emittance and a 70 mm airspace to

the wall lining, an added R-Value of 0.43; and

(C) with an inner reflective surface of 0.05 emittance and a 70 mm airspace to

the wall lining and an outer anti-glare reflective surface of 0.20 emittance and

a 25 mm airspace to the wall cladding, an added R-Value of 0.95; and

(D) with an outer anti-glare reflective surface of 0.20 emittance and a 35 mm

airspace to the wall cladding, an added R-Value of 0.50; and

(ii) within a roof where the reflective insulation is laid directly under the roof, those in

Table 2c.

Table 2c TYPICAL THERMAL PROPERTIES FOR REFLECTIVE SURFACES AND

AIRSPACES IN ROOFS

Emittance

of added

reflective

insulation

0.2 outer

0.05 inner

0.2 outer

0.05 inner

0.9 outer

0.05 inner

Direction of

heat flow

Pitched roof (10°) with

horizontal ceiling

Ventilated

roof space

R-Value added by a reflective surface

Nonventilated

roof space

Flat,

skillion or

pitched

roof (

Main Menu

ENERGY EFFICIENCY

Spec J1.2 – 2.

Deemed-to-Satisfy Provisions

Table 2c TYPICAL THERMAL PROPERTIES FOR REFLECTIVE SURFACES AND AIRSPACES IN ROOFS— continued

Emittance

of added

reflective

insulation

0.9 outer

0.05 inner

Direction of

heat flow

Pitched roof (10°) with

horizontal ceiling

Ventilated

roof space

R-Value added by a reflective surface

Nonventilated

roof space

Flat,

skillion or

pitched

roof (

Main Menu

ENERGY EFFICIENCY

SPECIFICATION J1.3

ROOF AND CEILING CONSTRUCTION

Deemed-to-Satisfy Provisions

1. Scope

This Specification describes the thermal performance of some common forms of roof and ceiling

construction.

2. Construction Deemed-to-Satisfy

Figure 2 details the R-Values considered to be achieved by some common forms of roof and

ceiling construction.

Figure 2 TYPICAL R-VALUES FOR ROOF AND CEILING CONSTRUCTION

Roof construction description Item Item description R-Value

Unventilated

(a) Roof 15° to 45° pitch

– Horizontal ceiling

– Metal cladding

1. Outdoor air film

(7 m/s)

R-Value

Ventilated

Up Down Up Down

0.03 0.03 0.03 0.03

2. Metal cladding 0.00 0.00 0.00 0.00

3. Roof airspace

(non-reflective)

0.18 0.28 0.00 0.46

4. Plasterboard, 0.06 0.06 0.06 0.06

gypsum (10 mm,

880 kg/m 3 )

5. Indoor air film 0.11 0.16 0.11 0.16

(still air)

Total R-Value 0.38 0.53 0.20 0.71

BCA 2009 Volume One **Australian** **Building** **Codes** **Board** Page 430

Main Menu

ENERGY EFFICIENCY

Spec J1.3 – 2.

Deemed-to-Satisfy Provisions

Figure 2 TYPICAL R-VALUES FOR ROOF AND CEILING CONSTRUCTION— continued

Roof construction description Item Item description R-Value

Unventilated

(b) Roof 15° to 45° pitch

– Horizontal ceiling

– Clay tiles 19 mm

1. Outdoor air film

(7 m/s)

R-Value

Ventilated

Up Down Up Down

0.03 0.03 0.03 0.03

2. Roof tile, clay or 0.02 0.02 0.02 0.02

concrete

(1922 kg/m 3 )

3. Roof airspace 0.18 0.28 0.00 0.46

(non-reflective)

4. Plasterboard, 0.06 0.06 0.06 0.06

gypsum (10 mm,

880 kg/m 3 )

5. Indoor air film 0.11 0.16 0.11 0.16

(still air)

Total R-Value 0.40 0.55 0.22 0.73

Figure 2 TYPICAL R-VALUES FOR ROOF AND CEILING CONSTRUCTION

Roof construction description Item Item

description

(c) Cathedral ceiling 15° to 45° pitch

– 10 mm plaster on top of rafters

1. Outdoor air

film (7 m/s)

R-Value Unventilated

Up Down

0.03 0.03

– Metal external cladding 2. Metal

0.00 0.00

cladding

3. Roof airspace 0.15 0.18

(30 mm to

100 mm,

non-reflective)

4. Plasterboard, 0.06 0.06

gypsum

(10 mm,

880 kg/m 3 )

5. Indoor air film 0.11 0.14

(still air)

Total R-Value 0.35 0.41

BCA 2009 Volume One **Australian** **Building** **Codes** **Board** Page 431

Main Menu

ENERGY EFFICIENCY

Spec J1.3 – 2.

Deemed-to-Satisfy Provisions

Figure 2 TYPICAL R-VALUES FOR ROOF AND CEILING CONSTRUCTION— continued

Roof construction description Item Item

description

(d) Cathedral ceiling 15° to 45° pitch

– 10 mm plaster on top of rafters

– Tiles external cladding

1. Outdoor air

film (7 m/s)

2. Roof tile, clay

or concrete

(1922 kg/m 3 )

3. Roof airspace

(30 mm to

100 mm,

non-reflective)

R-Value Unventilated

Up

Down

0.03 0.03

0.02 0.02

0.15 0.18

4. Plasterboard, 0.06 0.06

gypsum

(10 mm,

880 kg/m 3 )

5. Indoor air film 0.11 0.14

(still air)

Total R-Value 0.37 0.43

(e) Skillion roof less than 5° pitch

– 10 mm plaster below rafters

– Metal external cladding

1. Outdoor air

film (7 m/s)

0.03 0.03

2. Metal

0.00 0.00

cladding

3. Roof airspace 0.15 0.22

(100 mm to

300 mm,

non-reflective)

4. Plasterboard, 0.06 0.06

gypsum

(10 mm,

880 kg/m 3 )

5. Indoor air film 0.11 0.16

(still air)

Total R-Value 0.35 0.47

BCA 2009 Volume One **Australian** **Building** **Codes** **Board** Page 432

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ENERGY EFFICIENCY

Spec J1.3 – 2.

Deemed-to-Satisfy Provisions

Figure 2 TYPICAL R-VALUES FOR ROOF AND CEILING CONSTRUCTION— continued

(f)

Roof construction description Item Item

description

Skillion roof 5° to 15° pitch

– 10 mm plaster on top of rafters

– Metal external cladding

(g) 100 mm solid concrete roof to 5°

– 10 mm plaster, suspended ceiling

– Applied external waterproof membrane

1. Outdoor air

film (7 m/s)

R-Value Unventilated

Up

Down

0.03 0.03

2. Metal

0.00 0.00

cladding

3. Roof airspace 0.15 0.21

(30 mm to

100 mm

non-reflective)

4. Plasterboard, 0.06 0.06

gypsum

(10 mm,

880 kg/m 3 )

5. Indoor air film 0.11 0.16

(still air)

Total R-Value 0.35 0.46

1. Outdoor air 0.03 0.03

film (7 m/s)

2. Waterproof 0.03 0.03

membrane,

rubber

synthetic

(4 mm,

961 kg/m 3 )

3. Solid

0.07 0.07

concrete,

(100 mm,

2400 kg/m 3 )

4. Ceiling 0.15 0.22

airspace

(100 mm to

300 mm,

non-reflective)

5. Plasterboard, 0.06 0.06

gypsum

(10 mm,

880 kg/m 3 )

6. Indoor air film 0.11 0.16

(still air)

Total R-Value 0.45 0.57

BCA 2009 Volume One **Australian** **Building** **Codes** **Board** Page 433

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ENERGY EFFICIENCY

Spec J1.3 – 2.

Deemed-to-Satisfy Provisions

Figure 2 TYPICAL R-VALUES FOR ROOF AND CEILING CONSTRUCTION— continued

Roof construction description Item Item

description

R-Value Unventilated

Up

Down

Notes:

1. The R-Value of an item, other than an airspace, air film or air cavity, may be increased in

proportion to the increased thickness of the item.

2. The Total R-Value of a form of construction may be increased by the amount that the

R-Value of an individual item is increased.

3. Where an airspace is filled, the R-Value listed for the airspace must be deducted from the

Total R-Value of the roof construction.

4. For information on a roof space that is considered to be ventilated, see

Specification J1.2, Clause 2(d).

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ENERGY EFFICIENCY

SPECIFICATION J1.5

WALL CONSTRUCTION

Deemed-to-Satisfy Provisions

1. Scope

This Specification describes the thermal performance of some common forms of external wall

construction.

2. Construction Deemed-to-Satisfy

Figure 2 details the R-Values considered to be achieved by some common forms of wall

construction.

Figure 2 TYPICAL R-VALUES FOR WALL CONSTRUCTION

(a)

External wall construction description Item Item description R-Value

Masonry veneer – 25 mm to 50 mm cavity, 1. Outdoor air film (7 m/s) 0.03

10 mm internal plaster on 90 mm stud frame

2. Masonry (See notes 3 0.09

and 4)

3. Cavity and airspace (115 0.17

to 140 mm, made up of

90 mm stud + 25 mm to

50 mm airspace

non-reflective and

unventilated)

4. Plasterboard, gypsum 0.06

(10 mm, 880 kg/m 3 )

5. Indoor air film (still air) 0.12

Total R-Value 0.47

(b)

Cavity masonry – 20 mm to 50 mm cavity,

10 mm internal plaster on battens or furring

channels

1. Outdoor air film (7 m/s) 0.03

2. Masonry (See notes 3 0.09

and 4)

3. Masonry cavity (20 mm to 0.17

50 mm, non-reflective and

unventilated)

4. Masonry (See note 4) 0.09

5. Airspace (20 mm to

0.17

35 mm, non-reflective and

unventilated)

6. Plasterboard, gypsum 0.06

(10 mm, 880 kg/m 3 )

7. Indoor air film (still air) 0.12

Total R-Value 0.73

BCA 2009 Volume One **Australian** **Building** **Codes** **Board** Page 435

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ENERGY EFFICIENCY

Spec J1.5 – 2.

Deemed-to-Satisfy Provisions

Figure 2 TYPICAL R-VALUES FOR WALL CONSTRUCTION— continued

(c)

(d)

External wall construction description Item Item description R-Value

Denseweight hollow concrete block with

internal plaster on battens or furring channels

125 mm solid reinforced concrete (dense

weight) – 10 mm internal plaster on battens or

furring channels

1. Outdoor air film (7 m/s) 0.03

2. Denseweight hollow

concrete block (See notes

3 and 4)

3. Airspace (20 mm to

40 mm non-reflective and

unventilated)

4. Plasterboard, gypsum

(10 mm, 880 kg/m 3 )

0.15

0.17

0.06

5. Indoor air film (still air) 0.12

Total R-Value 0.53

1. Outdoor air film (7 m/s) 0.03

2. 125 mm minimum solid

reinforced concrete (See

note 3)

3. Airspace (20 mm to

40 mm non-reflective and

unventilated)

4. Plasterboard, gypsum

(10 mm, 880 kg/m 3 )

0.09

0.17

0.06

5. Indoor air film (still air) 0.12

Total R-Value 0.47

(e)

Timber wall – external 6 mm cement sheet

cladding, 90 mm stud frame, 10 mm plaster

1. Outdoor air film (7 m/s) 0.03

2. Fibre cement (6 mm,

1360 kg/m 3 )

3. Airspace (90 mm

nonreflective and

unventilated)

4. Plasterboard, gypsum

(10 mm, 880 kg/m 3 )

0.03

0.17

0.06

5. Indoor air film (still air) 0.12

Total R-Value 0.41

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ENERGY EFFICIENCY

Spec J1.5 – 2.

Deemed-to-Satisfy Provisions

Figure 2 TYPICAL R-VALUES FOR WALL CONSTRUCTION— continued

External wall construction description Item Item description R-Value

(f) 200 mm autoclaved aerated concrete block –

10 mm internal plaster on battens or furring

channels

1. Outdoor air film (7 m/s) 0.03

2. Autoclaved aerated

concrete block (200 mm,

350 kg/m 3 )

3. Airspace (20 mm to

40 mm non-reflective and

unventilated)

4. Plasterboard, gypsum

(10 mm, 880 kg/m 3 )

2.00

0.17

0.06

5. Indoor air film (still air) 0.12

Total R-Value 2.38

(g)

(h)

150 mm hollow-core concrete panels – 10 mm

internal plaster on battens or furring channels

Denseweight hollow concrete block with

external 6 mm cement sheet cladding on

battens or furring channels

1. Outdoor air film (7 m/s) 0.03

2. Prestressed hollow-core

concrete panels (150 mm,

1,680 kg/m 3 , 30% cores)

3. Airspace (20 mm to

40 mm non-reflective and

unventilated)

4. Plasterboard, gypsum

(10 mm, 880 kg/m 3 )

0.14

0.17

0.06

5. Indoor air film (still air) 0.12

Total R-Value 0.52

1. Outdoor air film (7 m/s) 0.03

2. Fibre cement (6 mm,

1360 kg/m 3 )

3. Airspace (20 mm to 40

mm non-reflective and

unventilated)

4. Denseweight hollow

concrete block (See note

4)

0.03

0.17

0.15

5. 10 mm render 0.02

6. Indoor air film (still air) 0.12

Total R-Value 0.52

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ENERGY EFFICIENCY

Spec J1.5 – 2.

Deemed-to-Satisfy Provisions

Figure 2 TYPICAL R-VALUES FOR WALL CONSTRUCTION— continued

External wall construction description Item Item description R-Value

Notes:

1. The R-Value of an item, other than an airspace, air film or air cavity, may be increased in

proportion to the increased thickness of the item.

2. The Total R-Value of a form of construction may be increased by the amount that an individual

item is increased.

3. The addition of 10 mm of render to a concrete or masonry wall will increase the Total R-Value by

0.02.

4. (a) The typical R-Value in Figure 2(a) and (b) is for 90 mm denseweight concrete block.

(b) The typical R-Value in Figure 2(c) and (h) is for 140 mm denseweight hollow concrete

block.

(c) The typical R-Value in Figure 2(d) is for 125 mm solid reinforced concrete (2400 kg/m 3 ).

(d) Other typical R-Values for masonry and concrete are as follows and may be substituted

for those above:

90 mm clay brick:

(density 1430 kg/m 3 ) 0.16

(density 1690 kg/m 3 ) 0.14

(density 1950 kg/m 3 ) 0.12

110 mm clay brick:

(density 1430 kg/m 3 , 2.75 kg/brick) 0.20

(density 1690 kg/m 3 , 3.25 kg/brick) 0.17

(density 1950 kg/m 3 , 3.75 kg/brick) 0.14

Denseweight hollow concrete block:

110 mm 0.12

190 mm 0.20

5. The Total R-Values in this Figure are for external walls. The Total R-Value for an internal wall of

the same construction would be 0.09 greater because the R-Value for an outdoor air film would be

replaced by that of an indoor air film.

6. Where a cavity or airspace is filled, the R-Value listed for the cavity must be deducted from the

Total R-Value of the wall.

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ENERGY EFFICIENCY

SPECIFICATION J1.6

FLOOR CONSTRUCTION

Deemed-to-Satisfy Provisions

1. Scope

This Specification describes the thermal performance of some common forms of floor

construction.

2. Construction Deemed-to-Satisfy

Figure 2 details the R-Values considered to be achieved by some common forms of floor

construction, other than a concrete floor with an embedded floor heating system.

Figure 2 TYPICAL R-VALUES FOR FLOOR CONSTRUCTION (for a floor without a floor

heating system)

Floor construction description Item Item description R-Value

(a) Timber internal floor, 10 mm internal

plaster

(b) Timber, suspended ground floor, open

sub-floor

Up

Down

1. Indoor air film (still air) 0.11 0.16

2. Particleboard flooring (19 mm,

640 kg/m 3 )

3. Floor airspace, 100 mm to

300 mm (non reflective)

4. Plasterboard, gypsum (10 mm,

880 kg/m 3 )

0.15 0.15

0.15 0.22

0.06 0.06

5. Indoor air film (still air) 0.11 0.16

Total R-Value 0.58 0.75

1. Indoor air film (still air) 0.11 0.16

2. Particleboard flooring (19 mm,

640 kg/m 3 )

0.15 0.15

3. Outdoor air film (7 m/s) 0.03 0.03

Total R-Value 0.29 0.34

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ENERGY EFFICIENCY

Spec J1.6 – 2.

Deemed-to-Satisfy Provisions

Figure 2 TYPICAL R-VALUES FOR FLOOR CONSTRUCTION (for a floor without a floor heating system)— continued

Floor construction description Item Item description R-Value

(c) Solid concrete suspended slab,

ground floor

Up

Down

1. Indoor air film (still air) 0.11 0.16

2. Solid concrete (150 mm,

2400 kg/m 3 )

0.10 0.10

3. Outdoor air film (7 m/s) 0.03 0.03

Total R-Value 0.24 0.29

(d) 150 mm hollow-core concrete planks,

ground floor

1. Indoor air film (still air) 0.11 0.16

2. Concrete topping (60 mm,

2,400 kg/m 3 )

3. Hollow-core concrete planks

(150 mm, 1,680 kg/m 3 , 30%

cores)

0.04 0.04

0.14 0.14

4. Outdoor air film (7 m/s) 0.03 0.03

Total R-Value 0.32 0.37

Notes:

1. The R-Value of an item, other than an air space, air film or air cavity, may be increased in

proportion to the increased thickness of the item.

2. The Total R-Value of a form of construction may be increased by the amount that an individual item

is increased.

3. For floor types (c) and (d) that are located over an internal space, the Total R-Value can be

calculated by replacing the value for outdoor air film (R0.03) on the underside of the floor with the

value for indoor air film (R0.11).

4. The addition of 10 mm of render to the ceiling of a suspended internal concrete floor will increase

the Total R-Value by 0.02.

5. Solid concrete slab includes concrete beam and infill floors and concrete precast permanent

formwork panels.

6. Where an airspace is filled, the R-Value listed for the airspace must be deducted from the Total

R-Value of the floor construction.

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