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BUILDING (SCOTLAND) ACT 2003 CONSULTATION ON BUILDING REGULATIONS
AND GUIDANCE DOCUMENT: NON DOMESTIC
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Annex 6.A Tables of U-values and thermal conductivity
6.A.0 Introduction
6.A.1 — 3 Tables of windows, rooflights and doors
6.A.4 — 7 Tables of roofs (example calculations 1 — 3)
6.A.8 — 11 Tables of walls (example calculations 4 — 7)
6.A.12 — 14 Tables of ground floors (example calculations 8 —
9)
6.A.15 — 17 Tables of upper floors
6.A.18 Table of thermal conductivity of building materials
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annex 6.A
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Tables of U-values and thermal conductivity
[Appendix
A]
6.A.0 Introduction
The U-value tables in this Annex give a "ready reckoner"
approach to establishing the U-values of construction elements. If a more
accurate calculation is appropriate for the design of the building then,
for roofs, walls and floors, the procedures in Annexes B and C can be
used. When using the U-value tables, the following should be borne in
mind
- The values in these tables have been derived using the Combined Method,
taking into account the effects of thermal bridging where appropriate.
- Intermediate values can be obtained from the tables by linear interpolation.
The last table of this Annex gives thermal conductivities of some common
building materials. If however certified test values are available, these
should be used in preference to those given in the table.
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Windows, rooflights and doors
Low-E coatings
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Full details about calculating the U-value of a window
or door are given in BS EN ISO 10077-1. This Annex provides
indicative U-values for windows, rooflights and doors. Table 6.A.1
applies to windows (and rooflights) with wood or plastic frames. Table
6.A.2 applies to windows with metal frames, for which the adjustments
(for thermal breaks and/or rooflights) in Table 6.A.3 should be applied.
The U-value of a window or rooflight containing low-E
glazing is influenced by the emissivity, en,
of the low-E coating. Low-E coatings are of two principal types, known
as ‘hard’ and ‘soft’. Hard coatings generally have
emissivities in the range 0.15 to 0.2, and the data for en
= 0.2 should be used for hard coatings, if the emissivity is not specified
or if the glazing is stated to be low-E but the type of coating is not
specified. Soft coatings generally have emissivities in the range 0.05
to 0.1. The data for en = 0.1 should
be used for a soft coating if the emissivity is not specified.
When available, manufacturers’ U-values, certified
by a notified body, for windows, or rooflights or doors should be used
in preference to the data given in these tables.
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Table 6.A.1: Indicative U-values (W/m2K)
for windows with wood or plastic frames [Note 1]
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Gap between panes
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6 mm
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12 mm
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16 mm or more
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Single glazing 4.8
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Double glazing (air filled)
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3.1
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2.8
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2.7
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Double glazing (low-E, en = 0.2)
[Note 2]
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2.7
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2.3
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2.1
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Double glazing (low-E, en = 0.15)
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2.7
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2.2
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2.0
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Double glazing (low-E, en = 0.1)
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2.6
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2.1
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1.9
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Double glazing (low-E, en = 0.05)
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2.6
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2.0
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1.8
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Double glazing (argon filled) [Note 3]
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2.9
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2.7
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2.6
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Double glazing (low-E, en = 0.2,
argon filled)
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2.5
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2.1
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2.0
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Double glazing (low-E, en = 0.15,
argon filled)
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2.4
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2.0
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1.9
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Double glazing (low-E, en = 0.1,
argon filled)
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2.3
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1.9
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1.8
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Double glazing (low-E, en = 0.05,
argon filled)
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2.3
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1.8
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1.7
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Triple glazing
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2.4
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2.1
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2.0
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Triple glazing (low-E, en = 0.2)
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2.1
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1.7
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1.6
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Triple glazing (low-E, en = 0.1)
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2.0
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1.6
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1.5
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Triple glazing (low-E, e n = 0.05)
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1.9
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1.5
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1.4
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Triple glazing (argon filled)
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2.2
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2.0
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1.9
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Triple glazing (low-E, en = 0.2,
argon filled)
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1.9
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1.6
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1.5
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Triple glazing (low-E, en = 0.1,
argon filled)
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1.8
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1.4
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1.3
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Triple glazing (low-E, en = 0.05,
argon filled)
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1.7
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1.4
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1.3
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Solid wooden door [Note 4] 3.0
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Notes: 1. The U-values in this table are based on the frame
comprising 30% of the total window area.
2. The emissivities quoted are normal emissivities.
(Corrected emissivity is used in the calculation of glazing U-values.) Uncoated
glass is assumed to have a normal emissivity of 0.89.
3. The gas mixture is assumed to consist of 90% argon
and 10% air.
4. For doors which are half-glazed the U-value of the
door is the average of the appropriate window U-value and that of the non-glazed
part of the door (e.g. 3.0 W/m2K for a wooden door).
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Table 6.A.2: Indicative U-values (W/m2K)
for windows with metal frames
(4 mm thermal break) [Notes 1 and 2]
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gap between panes
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6 mm
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12 mm
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16 mm
or more
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Single glazing 5.7
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Double glazing (air filled)
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3.7
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3.4
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3.3
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Double glazing (low-E, e n
= 0.2)
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3.3
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2.8
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2.6
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Double glazing (low-E, e n
= 0.15)
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3.3
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2.7
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2.5
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Double glazing (low-E, e n
= 0.1)
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3.2
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2.6
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2.5
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Double glazing (low-E, en
= 0.05)
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3.1
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2.5
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2.3
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Double glazing (argon filled)
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3.5
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3.3
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3.2
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Double glazing (low-E, en
= 0.2,argon filled)
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3.1
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2.6
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2.5
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Double glazing (low-E, en
= 0.15,argon filled)
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3.0
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2.5
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2.4
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Double glazing (low-E, en
= 0.1, argon filled)
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2.9
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2.4
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2.3
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Double glazing (low-E, en
= 0.05, argon filled)
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2.8
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2.3
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2.1
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Triple glazing
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2.9
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2.6
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2.5
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Triple glazing (low-E, en
= 0.2)
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2.6
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2.2
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2.0
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Triple glazing (low-E, en
= 0.1)
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2.5
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2.0
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1.9
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Triple glazing (low-E, en
= 0.05)
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2.4
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1.9
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1.8
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Triple glazing (argon-filled)
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2.8
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2.5
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2.4
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Triple glazing (low-E, en
= 0.2, argon filled)
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2.4
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2.0
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1.9
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Triple glazing (low-E, en
= 0.1, argon filled)
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2.2
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1.9
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1.8
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Triple glazing (low-E, en
= 0.05, argon filled)
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2.2
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1.8
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1.7
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Notes:
1. The U-values in this table are based on the frame comprising 20% of
the total window area.
2. For windows (or rooflights) with
metal frames incorporating a thermal break other than 4 mm, the adjustments
given in Table 6.A.3 should be made to the U-values given in Table 6.A.2.
Table 6.A.3: Adjustments to U-values in Table 6.A.2
for frames with thermal breaks
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Thermal break (mm)
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Adjustment to U-value (W/m2K)
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Window or rooflight in a non-domestic building
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0 (no break)
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+ 0.3
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4
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+ 0.0
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8
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- 0.1
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12
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- 0.2
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16
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- 0.2
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Note: For intermediate thicknesses of thermal breaks,
linear interpolation may be used.
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Roofs
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Table 6.A.4: Base thickness of insulation between
ceiling joists or rafters
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Design U-value
(W/m2K)
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Thermal conductivity of insulant (W/m·K)
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0.020
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0.025
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0.030
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0.035
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0.040
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0.045
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0.050
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Base thickness of insulating material (mm)
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A
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B
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C
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D
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E
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F
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G
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H
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1
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0.15
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371
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464
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557
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649
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742
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835
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928
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2
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0.20
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180
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224
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269
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314
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359
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404
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449
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3
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0.25
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118
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148
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178
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207
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237
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266
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296
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4
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0.30
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92
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110
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132
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154
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176
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198
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220
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5
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0.35
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77
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91
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105
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122
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140
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157
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175
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6
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0.40
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67
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78
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90
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101
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116
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130
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145
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Table 6.A.5: Base thickness of insulation between
and over joists or rafters
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Design U-value
(W/m2K)
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Thermal conductivity of insulant (W/m·K)
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0.020
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0.025
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0.030
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0.035
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0.040
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0.045
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0.050
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Base thickness of insulating material (mm)
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A
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B
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C
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D
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E
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F
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G
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H
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1
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0.15
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161
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188
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217
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247
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277
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307
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338
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2
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0.20
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128
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147
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167
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188
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210
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232
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255
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3
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0.25
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108
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122
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137
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153
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170
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187
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205
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4
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0.30
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92
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105
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117
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130
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143
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157
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172
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5
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0.35
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77
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91
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103
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113
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124
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136
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148
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6
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0.40
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67
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78
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90
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101
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110
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120
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130
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Note:
Tables 6.A.4 and 6.A.5 are derived for roofs with the
proportion of timber at 8%, corresponding to 48 mm wide timbers at
600 mm centres, excluding dwangs. For other proportions of timber
the U-value can be calculated using the procedure in Annex
B.
Table 6.A.6: Base thickness for continuous
insulation
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Design U-value
(W/m2K)
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Thermal conductivity of insulant (W/m·K)
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0.020
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0.025
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0.030
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0.035
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0.040
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0.045
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0.050
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Base thickness of insulating material (mm)
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A
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B
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C
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D
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E
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F
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G
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H
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1
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0.15
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131
|
163
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196
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228
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261
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294
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326
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2
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0.20
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97
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122
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146
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170
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194
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219
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243
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3
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0.25
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77
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97
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116
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135
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154
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174
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193
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4
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0.30
|
64
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80
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96
|
112
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128
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144
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160
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5
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0.35
|
54
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68
|
82
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95
|
109
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122
|
136
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6
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0.40
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47
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59
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71
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83
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94
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106
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118
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Table 6.A.7: Allowable reductions in thickness
for common roof components
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Concrete slab density (kg/m3)
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Thermal conductivity of insulant (W/m·K)
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0.020
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0.025
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0.030
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0.035
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0.040
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0.045
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0.050
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Reduction in base thickness of insulating material
(mm) for each 100 mm of concrete slab
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A
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B
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C
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D
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E
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F
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G
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H
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1
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600
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10
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13
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15
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18
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20
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23
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25
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2
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800
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7
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9
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11
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13
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14
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16
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18
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3
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1100
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5
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6
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8
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9
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10
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11
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13
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4
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1300
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4
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5
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6
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7
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8
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9
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10
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5
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1700
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2
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2
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3
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3
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4
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4
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5
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6
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2100
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1
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2
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2
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2
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3
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3
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3
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Other materials and components
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Reduction in base thickness of insulating material
(mm)
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A
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B
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C
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D
|
E
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F
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G
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H
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7
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10 mm plasterboard
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1
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2
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2
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2
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3
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3
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3
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8
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13 mm plasterboard
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2
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2
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2
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3
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3
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4
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4
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9
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13 mm sarking board
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2
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2
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3
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3
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4
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4
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5
|
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10
|
12 mm calcium silicate liner board
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1
|
2
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2
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2
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3
|
3
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4
|
|
11
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Roof space (pitched)
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4
|
5
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6
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7
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8
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9
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10
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12
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Roof space (flat)
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3
|
4
|
5
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6
|
6
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7
|
8
|
|
13
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19 mm roof tiles
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0
|
1
|
1
|
1
|
1
|
1
|
1
|
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14
|
19 mm asphalt (or 3 layers of felt)
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1
|
1
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1
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1
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2
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2
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2
|
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15
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50 mm screed
|
2
|
3
|
4
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4
|
5
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5
|
6
|
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Example 1 - Pitched roof with insulation between ceiling
ties or between rafters
Determine the thickness of the insulation layer that
will achieve a U-value of 0.20 W/m2K if insulation is
between the ceiling ties, and 0.25 W/m2K if insulation
is between the rafters.
For insulation placed between ceiling ties (Design
U-value 0.20 W/m2K)
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Using Table 6.A.4:
From column D, row 2 of the table, the appropriate
base thickness of insulation is 269 mm.
The base thickness may be reduced by taking account of
the other materials as follows:
From Table 6.A.7:
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19 mm roof tiles
|
column D, row 13
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= 1 mm
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Roof space (pitched)
|
column D, row 11
|
= 6 mm
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10 mm plasterboard
|
column D, row 7
|
= 2 mm
|
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Total reduction
|
|
= 9 mm
|
|
To achieve a U-value of 0.20 W/m2K the
minimum thickness of the insulation layer between the ceiling ties is
therefore:
Base thickness less total reduction i.e.
269 — 9 = 260 mm.
For insulation placed between rafters (Design U-value
0.25 W/m2K)
|
|
Using Table 6.A.4:
From column D, row 4 in the table, the appropriate
base thickness of insulation is 178 mm.
The reductions in the base thickness are obtained as
follows:
From Table 6.A.7:
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19 mm roof tiles
|
column D, row 13
|
= 1 mm
|
|
10 mm plasterboard
|
column D, row 7
|
= 2 mm
|
|
Total reduction
|
|
= 3 mm
|
|
To achieve a U-value of 0.25 W/m2K the
minimum thickness of the insulation layer between the rafters is therefore:
Base thickness less total reduction i.e.178
- 3 = 175 mm.
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|
Example 2 - Pitched roof with insulation between and
over ceiling ties
Determine the thickness of the insulation layer above
the ceiling ties that will achieve a U-value of 0.20 W/m2K
for the roof construction shown below:
|
|
|
It is proposed to use mineral fibre insulation between
and over the ties with a thermal conductivity of 0.04 W/m·K.
Using Table 6.A.5:
From column F, row 2 of the table, the base thickness
of insulation layer is 210 mm.
The base thickness may be reduced by taking account of
the other materials as follows:
From Table 6.A.7:
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|
19 mm roof tiles
|
column F, row 13
|
= 1 mm
|
|
Roof space (pitched)
|
column F, row 11
|
= 8 mm
|
|
10 mm plasterboard
|
column F, row 7
|
= 3 mm
|
|
Total reduction
|
|
= 12 mm
|
|
To achieve a U-value of 0.20 W/m2K the
minimum thickness of the insulation layer over the joists, in addition
to the 100 mm insulation between the joists, is therefore:
Base thickness less total reduction i.e.
210 - 1OO - 12 = 98 mm.
Example 3: Concrete deck roof
Determine the thickness of the insulation layer that
will achieve a U-value of 0.25 W/m2K for the roof construction
shown below.
|
|
Using Table 6.A.6:
From column D, row 3 of the table, the base thickness
of the insulation layer is 116 mm.
The base thickness may be reduced by taking account of
the other materials as follows:
From Table 6.A.7:
|
|
3 layers of felt
|
column D, row 14
|
= 1 mm
|
|
150 mm concrete deck adjusted for 150 mm thickness
(1.5 x 8)
|
column D, row 3
|
= 12 mm
|
|
Total reduction
|
|
= 13 mm
|
|
To achieve a U-value of 0.25 W/m2K, the
minimum thickness of the insulation layer is therefore:
Base thickness less total reduction i.e.
116 - 13 = 103 mm.
|
|
Walls
|
|
Table 6.A.8: Base thickness of insulation layer
|
|
Design U-value
(W/m2K)
|
Thermal conductivity of insulant (W/m·K)
|
|
0.020
|
0.025
|
0.030
|
0.035
|
0.040
|
0.045
|
0.050
|
|
Base thickness of insulating material (mm)
|
|
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
|
1
|
0.20
|
97
|
121
|
145
|
169
|
193
|
217
|
242
|
|
2
|
0.25
|
77
|
96
|
115
|
134
|
153
|
172
|
192
|
|
3
|
0.30
|
63
|
79
|
95
|
111
|
127
|
142
|
158
|
|
4
|
0.35
|
54
|
67
|
81
|
94
|
107
|
121
|
134
|
|
5
|
0.40
|
47
|
58
|
70
|
82
|
93
|
105
|
117
|
|
6
|
0.45
|
41
|
51
|
62
|
72
|
82
|
92
|
103
|
Table 6.A.9: Allowable reductions in base thickness for
common components
|
|
Component
|
Thermal conductivity of insulant (W/m·K)
|
|
0.020
|
0.025
|
0.030
|
0.035
|
0.040
|
0.045
|
0.050
|
|
Reduction in base thickness of insulating material
(mm)
|
|
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
|
1
|
Cavity (25 mm)
|
4
|
5
|
5
|
6
|
7
|
8
|
9
|
|
2
|
Outer leaf brick
|
3
|
3
|
4
|
5
|
5
|
6
|
6
|
|
3
|
13 mm plaster
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
|
4
|
13 mm lightweight plaster
|
2
|
2
|
2
|
3
|
3
|
4
|
4
|
|
5
|
9.5 mm plasterboard
|
1
|
2
|
2
|
2
|
3
|
3
|
3
|
|
6
|
12.5 mm plasterboard
|
2
|
2
|
2
|
3
|
3
|
4
|
4
|
|
7
|
Air space behind plasterboard dry lining
|
2
|
3
|
4
|
4
|
5
|
5
|
6
|
|
8
|
9 mm sheathing ply
|
1
|
2
|
2
|
2
|
3
|
3
|
3
|
|
9
|
20 mm cement render
|
1
|
1
|
1
|
1
|
2
|
2
|
2
|
|
10
|
13 mm tile hanging
|
0
|
0
|
0
|
1
|
1
|
1
|
1
|
|
|
Table 6.A.10: Allowable reductions in base thickness
for concrete components
|
|
Density
(Kg/m2)
|
Thermal conductivity of insulant (W/m·K)
|
|
0.020
|
0.025
|
0.030
|
0.035
|
0.040
|
0.045
|
0.050
|
|
Reduction in base thickness of insulation (mm)
for each 100 mm of concrete
|
|
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
|
Concrete inner leaf
|
|
1
|
600
|
9
|
11
|
13
|
15
|
17
|
20
|
22
|
|
2
|
800
|
7
|
9
|
10
|
12
|
14
|
16
|
17
|
|
3
|
1000
|
5
|
6
|
8
|
9
|
10
|
11
|
13
|
|
4
|
1200
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
|
5
|
1400
|
3
|
4
|
5
|
6
|
7
|
8
|
8
|
|
6
|
1600
|
3
|
3
|
4
|
5
|
6
|
6
|
7
|
|
7
|
1800
|
2
|
2
|
3
|
3
|
4
|
4
|
4
|
|
8
|
2000
|
2
|
2
|
2
|
3
|
3
|
3
|
4
|
|
9
|
2400
|
1
|
1
|
2
|
2
|
2
|
2
|
3
|
|
Concrete outer leaf or single leaf wall
|
|
10
|
600
|
8
|
11
|
13
|
15
|
17
|
19
|
21
|
|
11
|
800
|
7
|
9
|
10
|
12
|
14
|
15
|
17
|
|
12
|
1000
|
5
|
6
|
7
|
8
|
10
|
11
|
12
|
|
13
|
1200
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
|
14
|
1400
|
3
|
4
|
5
|
6
|
6
|
7
|
8
|
|
15
|
1600
|
3
|
3
|
4
|
5
|
5
|
6
|
7
|
|
16
|
1800
|
2
|
2
|
3
|
3
|
3
|
4
|
4
|
|
17
|
2000
|
1
|
2
|
2
|
3
|
3
|
3
|
4
|
|
18
|
2400
|
1
|
1
|
2
|
2
|
2
|
2
|
3
|
Table 6.A.11: Allowable reductions in base thickness
for insulated timber framed walls
|
|
Thermal conductivity of insulation within frame
(W/m·K)
|
Thermal conductivity of insulant (W/m·K)
|
|
0.020
|
0.025
|
0.030
|
0.035
|
0.040
|
0.045
|
0.050
|
|
Reduction in base thickness of insulation
material (mm) for each 100 mm of frame (mm)
|
|
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
|
1
|
0.035
|
42
|
53
|
63
|
74
|
84
|
95
|
105
|
|
2
|
0.040
|
38
|
48
|
58
|
67
|
77
|
87
|
96
|
Note:
The table is derived for walls for which the proportion
of timber is 12%, which corresponds to 48 mm wide studs at 400 mm
centres. For other proportions of timber the U-value can be calculated
using the procedure in Annex B.
Example 4 - Masonry cavity wall with internal insulation
(For buildings where sound resisting separating floors
and walls are provided, this construction may not provide appropriate
resistance to flanking sound transmission)
Determine the thickness of the insulation layer that
will achieve a U-value of 0.35 W/m2K for the wall construction
shown below.
|
|
|
Using Table 6.A.8:
From column C, row 4 of the table, the
base thickness of the insulation layer is 67 mm.
The base thickness may be reduced by taking account of
the other materials as follows:
From Table 6.A.9:
|
|
Brick outer leaf
|
column C, row 2
|
= 3 mm
|
|
Cavity
|
column C, row 1
|
= 5 mm
|
|
Plasterboard
|
column C, row 6
|
= 2 mm
|
|
And from table 6.A.10
|
|
Concrete block
|
column C, row 1
|
|
|
adjusted for 150 mm block thickness (1.5 x 11)
|
= 17 mm
|
|
Total reduction
|
|
= 27 mm
|
|
To achieve a U-value of 0.35 W/m2K, the
minimum thickness of the insulation layer is therefore:
Base thickness less total reduction i.e.
67 — 27 = 40 mm
|
|
|
Example 5 - Masonry cavity wall filled with insulation
with plasterboard on dabs
Determine the thickness of the insulation layer that
will achieve a U-value of 0.35 W/m2K for the wall construction
shown below. (This calculation assumes the effect of wall ties to be negligible).
|
|
Using Table 6.A.8:
From column F, row 4 of the table, the base thickness
of the insulation layer is 107 mm.
The base thickness may be reduced by taking account of
the other materials as follows:
From Table 6.A.9:
|
|
Brick outer leaf
|
column F, row 2 =
|
5 mm
|
|
Plasterboard
|
column F, row 6
|
= 3 mm
|
|
Air space behind plasterboard
|
column F, row 7
|
= 5 mm
|
|
And from Table 6.A.10:
|
|
Concrete block
|
column F, row 8
|
= 3 mm= 16 mm
|
|
Total reduction
|
|
|
|
To achieve a U-value of 0.35 W/m2K the
minimum thickness of the insulation layer is therefore:
Base thickness less total reduction i.e.
107 — 16 = 91 mm
|
|
|
Example 6 - Masonry wall with partial cavity-fill
Determine the thickness of the insulation layer that
will achieve a U-value of 0.30 W/m2K for the wall construction
shown below.
|
|
|
Using Table 6.A.8:
From column C, row 3 of the table, the base thickness
of the insulation layer is 79 mm.
The base thickness may be reduced by taking account of
the other materials as follows:
From Table 6.A.9:
|
|
Brick outer leaf
|
column C, row 2
|
= 3 mm
|
|
Cavity
|
column C, row 1
|
= 5 mm
|
|
Lightweight plaster
|
column C, row 4
|
= 2 mm
|
|
And from Table 6.A.10:
|
|
Concrete block
|
column C, row 5
|
= 4 mm
|
|
Total reduction
|
|
= 14 mm
|
|
To achieve a U-value of 0.30 W/m2K, the
minimum thickness of the insulation layer is therefore:
Base thickness less total reduction i.e.
79 — 14 = 65 mm
|
|
|
Example 7 - Timber-frame wall
Determine the thickness of the insulation layer that
will achieve a U-value of 0.30 W/m2K for the wall construction
shown below. (Note this construction may be inappropriate where the wall
should have a level of fire resistance.)
|
|
|
Using Table 6.A.8:
From column D, row 3 of the table, the base thickness
of the internal insulation layer is 95 mm.
The base thickness may be reduced by taking account of
the other materials as follows:
From Table 6.A.9:
|
|
Brick outer leaf
|
column D, row 2
|
= 4 mm
|
|
Cavity
|
column D, row 1
|
= 5 mm
|
|
Sheathing ply
|
column D, row 8
|
= 2 mm
|
|
Plasterboard
|
column D, row 6
|
= 2 mm
|
|
And from Table 6.A.11:
|
|
Timber frame adjusted for shallower member (0.9 x 63
mm)
|
column D, row 1
|
= 57 mm
|
|
Total reduction
|
|
= 70 mm
|
|
To achieve a U-value of 0.30 W/m2K the
minimum thickness of the internal insulation layer is therefore:
Base thickness less total reduction i.e.
95 — 70 = 25 mm
|
|
Ground floors
|
Note: In using the tables for floors, the P/A ratio
should be calculated first, where P is the floor perimeter
length in metres; and A is the floor area in m2.
Table 6.A.12: Insulation thickness for ground supported
solid floors
|
|
Thermal conductivity of insulant (W/m·K)
|
|
|
P/A
|
0.020
|
0.025
|
0.030
|
0.035
|
0.040
|
0.045
|
0.050
|
|
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
|
|
Insulation thickness (mm) for U-value of 0.20 W/m2K
|
|
1
|
1.00
|
81
|
101
|
121
|
142
|
162
|
182
|
202
|
|
2
|
0.90
|
80
|
100
|
120
|
140
|
160
|
180
|
200
|
|
3
|
0.80
|
78
|
98
|
118
|
137
|
157
|
177
|
196
|
|
4
|
0.70
|
77
|
96
|
115
|
134
|
153
|
173
|
192
|
|
5
|
0.60
|
74
|
93
|
112
|
130
|
149
|
167
|
186
|
|
6
|
0.50
|
71
|
89
|
107
|
125
|
143
|
160
|
178
|
|
7
|
0.40
|
67
|
84
|
100
|
117
|
134
|
150
|
167
|
|
8
|
0.30
|
60
|
74
|
89
|
104
|
119
|
134
|
149
|
|
9
|
0.20
|
46
|
57
|
69
|
80
|
92
|
103
|
115
|
|
|
Insulation thickness (mm) for U-value of 0.25 W/m2K
|
|
10
|
1.00
|
61
|
76
|
91
|
107
|
122
|
137
|
152
|
|
11
|
0.90
|
60
|
75
|
90
|
105
|
120
|
135
|
150
|
|
12
|
0.80
|
58
|
73
|
88
|
102
|
117
|
132
|
146
|
|
13
|
0.70
|
57
|
71
|
85
|
99
|
113
|
128
|
142
|
|
14
|
0.60
|
54
|
68
|
82
|
95
|
109
|
122
|
136
|
|
15
|
0.50
|
51
|
64
|
77
|
90
|
103
|
115
|
128
|
|
16
|
0.40
|
47
|
59
|
70
|
82
|
94
|
105
|
117
|
|
17
|
0.30
|
40
|
49
|
59
|
69
|
79
|
89
|
99
|
|
18
|
0.20
|
26
|
32
|
39
|
45
|
52
|
58
|
65
|
|
|
Insulation thickness (mm) for U-value of 0.30 W/m2K
|
|
19
|
1.00
|
48
|
60
|
71
|
83
|
95
|
107
|
119
|
|
20
|
0.90
|
47
|
58
|
70
|
81
|
93
|
105
|
116
|
|
21
|
0.80
|
45
|
56
|
68
|
79
|
90
|
102
|
113
|
|
22
|
0.70
|
43
|
54
|
65
|
76
|
87
|
98
|
108
|
|
23
|
0.60
|
41
|
51
|
62
|
72
|
82
|
92
|
103
|
|
24
|
0.50
|
38
|
47
|
57
|
66
|
76
|
85
|
95
|
|
25
|
0.40
|
33
|
42
|
50
|
59
|
67
|
75
|
84
|
|
26
|
0.30
|
26
|
33
|
39
|
46
|
53
|
59
|
66
|
|
27
|
0.20
|
13
|
16
|
19
|
22
|
25
|
28
|
32
|
Note: P/A is the ratio of floor perimeter (m)
to floor area (m2).
Table 6.A.13: Insulation thickness for suspended
timber ground floors
|
|
Thermal conductivity of insulant (W/m·K)
|
|
|
P/A
|
0.020
|
0.025
|
0.030
|
0.035
|
0.040
|
0.045
|
0.050
|
|
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
|
|
Insulation thickness (mm) for U-value of 0.20 W/m2K
|
|
1
|
1.00
|
127
|
145
|
164
|
182
|
200
|
218
|
236
|
|
2
|
0.90
|
125
|
144
|
162
|
180
|
198
|
216
|
234
|
|
3
|
0.80
|
123
|
142
|
160
|
178
|
195
|
213
|
230
|
|
4
|
0.70
|
121
|
139
|
157
|
175
|
192
|
209
|
226
|
|
5
|
0.60
|
118
|
136
|
153
|
171
|
188
|
204
|
221
|
|
6
|
0.50
|
114
|
131
|
148
|
165
|
181
|
198
|
214
|
|
7
|
0.40
|
109
|
125
|
141
|
157
|
173
|
188
|
204
|
|
8
|
0.30
|
99
|
115
|
129
|
144
|
159
|
173
|
187
|
|
9
|
0.20
|
82
|
95
|
107
|
120
|
132
|
144
|
156
|
|
|
Insulation thickness (mm) for U-value of 0.25 W/m2K
|
|
10
|
1.00
|
93
|
107
|
121
|
135
|
149
|
162
|
176
|
|
11
|
0.90
|
92
|
106
|
119
|
133
|
146
|
160
|
173
|
|
12
|
0.80
|
90
|
104
|
117
|
131
|
144
|
157
|
170
|
|
13
|
0.70
|
88
|
101
|
114
|
127
|
140
|
153
|
166
|
|
14
|
0.60
|
85
|
98
|
111
|
123
|
136
|
148
|
161
|
|
15
|
0.50
|
81
|
93
|
106
|
118
|
130
|
142
|
154
|
|
16
|
0.40
|
75
|
87
|
99
|
110
|
121
|
132
|
143
|
|
17
|
0.30
|
66
|
77
|
87
|
97
|
107
|
117
|
127
|
|
18
|
0.20
|
49
|
57
|
65
|
73
|
81
|
88
|
96
|
|
|
Insulation thickness (mm) for U-value of 0.30 W/m2K
|
|
19
|
1.00
|
71
|
82
|
93
|
104
|
114
|
125
|
135
|
|
20
|
0.90
|
70
|
80
|
91
|
102
|
112
|
122
|
133
|
|
21
|
0.80
|
68
|
78
|
89
|
99
|
109
|
119
|
129
|
|
22
|
0.70
|
66
|
76
|
86
|
96
|
106
|
116
|
126
|
|
23
|
0.60
|
63
|
73
|
82
|
92
|
102
|
111
|
120
|
|
24
|
0.50
|
59
|
68
|
78
|
87
|
96
|
104
|
113
|
|
25
|
0.40
|
53
|
62
|
70
|
79
|
87
|
95
|
103
|
|
26
|
0.30
|
45
|
52
|
59
|
66
|
73
|
80
|
87
|
|
27
|
0.20
|
28
|
33
|
38
|
42
|
47
|
51
|
56
|
Notes:
1. P/A is the ratio of floor perimeter
(m) to floor area (m2). The table is derived for suspended
timber floors for which the proportion of timber is 12%, which corresponds
to 48 mm wide timbers at 400 mm centres.
2. For other proportions of timber the U-value
can be calculated using the procedure in Annex
B.
Table 6.A.14: Insulation thickness for suspended concrete
beam and block ground floors
|
|
Thermal conductivity of insulant (W/m·K)
|
|
|
P/A
|
0.020
|
0.025
|
0.030
|
0.035
|
0.040
|
0.045
|
0.050
|
|
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
|
|
Insulation thickness (mm) for U-value of 0.20 W/m2K
|
|
1
|
1.00
|
82
|
103
|
123
|
144
|
164
|
185
|
205
|
|
2
|
0.90
|
81
|
101
|
122
|
142
|
162
|
183
|
203
|
|
3
|
0.80
|
80
|
100
|
120
|
140
|
160
|
180
|
200
|
|
4
|
0.70
|
79
|
99
|
118
|
138
|
158
|
177
|
197
|
|
5
|
0.60
|
77
|
96
|
116
|
135
|
154
|
173
|
193
|
|
6
|
0.50
|
75
|
93
|
112
|
131
|
150
|
168
|
187
|
|
7
|
0.40
|
71
|
89
|
107
|
125
|
143
|
161
|
178
|
|
8
|
0.30
|
66
|
82
|
99
|
115
|
132
|
148
|
165
|
|
9
|
0.20
|
56
|
69
|
83
|
97
|
111
|
125
|
139
|
|
|
Insulation thickness (mm) for U-value of 0.25 W/m2K
|
|
10
|
1.00
|
62
|
78
|
93
|
109
|
124
|
140
|
155
|
|
11
|
0.90
|
61
|
76
|
92
|
107
|
122
|
138
|
153
|
|
12
|
0.80
|
60
|
75
|
90
|
105
|
120
|
135
|
150
|
|
13
|
0.70
|
59
|
74
|
88
|
103
|
118
|
132
|
147
|
|
14
|
0.60
|
57
|
71
|
86
|
100
|
114
|
128
|
143
|
|
15
|
0.50
|
55
|
68
|
82
|
96
|
110
|
123
|
137
|
|
16
|
0.40
|
51
|
64
|
77
|
90
|
103
|
116
|
128
|
|
17
|
0.30
|
46
|
57
|
69
|
80
|
92
|
103
|
115
|
|
18
|
0.20
|
36
|
45
|
54
|
62
|
71
|
80
|
89
|
|
|
Insulation thickness (mm) for U-value of 0.30 W/m2K
|
|
19
|
1.00
|
49
|
61
|
73
|
85
|
97
|
110
|
122
|
|
20
|
0.90
|
48
|
60
|
72
|
84
|
96
|
108
|
120
|
|
21
|
0.80
|
47
|
59
|
70
|
82
|
94
|
105
|
117
|
|
22
|
0.70
|
45
|
57
|
68
|
80
|
91
|
102
|
114
|
|
23
|
0.60
|
44
|
55
|
66
|
77
|
88
|
98
|
109
|
|
24
|
0.50
|
41
|
52
|
62
|
72
|
83
|
93
|
104
|
|
25
|
0.40
|
38
|
48
|
57
|
67
|
76
|
86
|
95
|
|
26
|
0.30
|
33
|
41
|
49
|
57
|
65
|
73
|
81
|
|
27
|
0.20
|
22
|
28
|
33
|
39
|
44
|
50
|
56
|
Note:
P/A is the ratio of floor perimeter (m) to floor
area (m2).
|
|
|
Example 8 — Solid floor in contact with the ground
Determine the thickness of the insulation layer that
will achieve a U-value of 0.30 W/m2K for the ground floor
slab shown below.
|
|
|
It is proposed to use insulation with a thermal conductivity
of 0.025 W/m·K.
The overall perimeter length of the slab is: (10 + 4
+ 4 + 2 + 6 + 6) = 32 m.
The floor area of the slab is : (6 x 6) + (4 x 4) = 52 m2.
The ratio: 
Using Table 6.A.12, column C, row 23 indicates
that 51 mm of insulation is appropriate.
Example 9 - Suspended timber floor
If the floor shown above was of suspended timber construction,
the perimeter length and floor area would be the same, yielding the same
ratio of:
To achieve a U-value of 0.30 W/m2·K,
using insulation with a thermal conductivity of 0.04 W/m·K,
Table 6.A.13 column F, row 23 indicates that the insulation thickness
between the joists should be not less than 102 mm.
|
|
Upper floors
|
Table 6.A.15: Upper floors of timber construction
|
Design Uvalue
(W/m2K)
|
Thermal conductivity of insulant (W/m·K)
|
|
0.020
|
0.025
|
0.030
|
0.035
|
0.040
|
0.045
|
0.050
|
|
Base thickness of insulation between joists to
achieve design U-values
|
|
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
|
1
|
0.20
|
167
|
211
|
256
|
298
|
341
|
383
|
426
|
|
2
|
0.25
|
109
|
136
|
163
|
193
|
225
|
253
|
281
|
|
3
|
0.30
|
80
|
100
|
120
|
140
|
160
|
184
|
208
|
Note:
Table 6.A.15 is derived for floors with the proportion
of timber at 12% which corresponds to 48 mm wide timbers at 400 mm
centres. For other proportions of timber the U-value can be calculated
using the procedure in Annex B.
Table 6.A.16: Upper floors of concrete
construction
|
Design U-value
(W/m2K)
|
Thermal conductivity of insulant (W/m·K)
|
|
0.020
|
0.025
|
0.030
|
0.035
|
0.040
|
0.045
|
0.050
|
|
Base thickness of insulation to achieve design
U-value
|
|
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
|
1
|
0.20
|
95
|
119
|
142
|
166
|
190
|
214
|
237
|
|
2
|
0.25
|
75
|
94
|
112
|
131
|
150
|
169
|
187
|
|
3
|
0.30
|
62
|
77
|
92
|
108
|
123
|
139
|
154
|
Table 6.A.17: Upper floors: allowable reductions in
base thickness for common components
|
Component
|
Thermal conductivity of insulant (W/m·K)
|
|
0.020
|
0.025
|
0.030
|
0.035
|
0.040
|
0.045
|
0.050
|
|
Reduction in base thickness of insulation material
(mm)
|
|
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
|
1
|
10 mm plasterboard
|
1
|
2
|
2
|
2
|
3
|
3
|
3
|
|
2
|
19 mm timber flooring
|
3
|
3
|
4
|
5
|
5
|
6
|
7
|
|
3
|
50 mm screed
|
2
|
3
|
4
|
4
|
5
|
5
|
6
|
|
Table 6.A.18: Thermal conductivity of some common construction
materials
|
|
Density
(kg/m3)
|
Conductivity
(W/m·K)
|
|
Walls
|
Brickwork (outer leaf)
|
1700
|
0.77
|
|
Brickwork (inner leaf)
|
1700
|
0.56
|
|
Lightweight aggregate concrete block
|
1400
|
0.57
|
|
Autoclaved aerated concrete block
|
600
|
0.18
|
|
Concrete (medium density)
|
1800
|
1.13
|
|
2000
|
1.33
|
|
2200
|
1.59
|
|
Concrete (high density)
|
2400
|
1.93
|
|
Reinforced concrete (1% steel)
|
2300
|
2.3
|
|
Reinforced concrete (2% steel)
|
2400
|
2.5
|
|
Mortar (protected)
|
1750
|
0.88
|
|
Mortar (exposed)
|
1750
|
0.94
|
|
Gypsum
|
600
|
0.18
|
|
900
|
0.30
|
|
1200
|
0.43
|
|
Sandstone
|
2600
|
2.3
|
|
Limestone (soft)
|
1800
|
1.1
|
|
Limestone (hard)
|
2200
|
1.7
|
|
Timber (softwood, plywood, chipboard)
|
500
|
0.13
|
|
Timber (hardwood)
|
700
|
0.18
|
|
Surface finishes
|
Plasterboard
|
900
|
0.25
|
|
Fibreboard
|
400
|
0.1
|
|
Tiles (ceramic)
|
2300
|
1.3
|
|
External rendering
|
1300
|
0.57
|
|
Plaster (dense)
|
1300
|
0.57
|
|
Plaster (lightweight)
|
600
|
0.18
|
|
Roofs
|
Aerated concrete slab
|
500
|
0.16
|
|
Asphalt
|
2100
|
0.70
|
|
Felt/bitumen layers
|
1100
|
0.23
|
|
Screed
|
1200
|
0.41
|
|
Stone chippings
|
2000
|
2.0
|
|
Tiles (clay)
|
2000
|
1.0
|
|
Tiles (concrete)
|
2100
|
1.5
|
|
Wood wool slab
|
500
|
0.10
|
|
Floors
|
Cast concrete
|
2000
|
1.35
|
|
Metal tray (steel)
|
7800
|
50.0
|
|
Screed
|
1200
|
0.41
|
|
Timber (hardwood)
|
700
|
0.18
|
|
Timber (softwood, plywood, chipboard)
|
500
|
0.13
|
|
Insulation
|
Expanded polystyrene (EPS) slab
|
15
|
0.040
|
|
Mineral wool quilt
|
12
|
0.042
|
|
Mineral wool batt
|
25
|
0.038
|
|
Phenolic foam board
|
30
|
0.025
|
|
Polyurethane board
|
30
|
0.025
|
Note: If available, certified test values should
be used in preference to those in the table.
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