1) This Section applies to thermal insulation and
measures to control heat transfer, air leakage and condensation.
2) Insulation and sealing of heating and ventilating
ducts shall conform to Sections 9.32. and 9.33.
1 ) Sheet and panel-type materials shall be installed in
accordance with Sentence (2), if the material
a)has an air leakage characteristic less than 0.1 L/(s•m2) at 75 Pa,
b)has a water vapour permeance less than 60 ng/(Pa•s•m2) when measured in accordance with ASTM E 96, “Water Vapor Transmission of Materials,” using the desiccant method (dry cup), and
c)is incorporated into a building assembly required by Article 9.25.2.1. to be insulated.
2) Sheet and panel-type material described in
Sentence (1) shall be installed
a)on the warm face of the assembly (see also Article 9.25.4.2.),
b) except as provided in Sentences (3) to (5) , at a location where the ratio between the total thermal resistance of all materials outboard of its innermost impermeable surface and the total thermal resistance of all materials inboard of that surface is not less than that required by Table 9.25.1.2., or
c)outboard of an air space that is vented to the outdoors and, for walls, drained.
| Table 9.25.1.2. Ratio of Outboard to Inboard Thermal Resistance Forming Part of Sentence 9.25.1.2.(2) |
|
| Heating Degree-Days of Building Location(1), Celsius degree-days | Minimum Ratio, Total Thermal Resistance Outboard of Material's Inner Surface to Total Thermal Resistance Inboard of Material's Inner Surface |
|---|---|
| up to 4 999 | 0.20 |
| 5 000 to 5 999 | 0.30 |
| 6 000 to 6 999 | 0.35 |
| 7 000 to 7 999 | 0.40 |
| 8 000 to 8 999 | 0.50 |
| 9 000 to 9 999 | 0.55 |
| 10 000 to 10 999 | 0.60 |
| 11 000 to 11 999 | 0.65 |
| 12 000 or higher | 0.75 |
| Notes to Table 9.25.1.2. | |
|
|
|
| (1) | See Sentence 1.1.3.1.(1). |
3) Wood-based sheathing materials not more than
12.5 mm thick and complying with Article 9.23.16.2. need not comply with Sentence (1).
4) Where the mild climate indicator, determined in
accordance with Sentence (6), is greater than 6 300, the position of low air- and vapour-permeance materials within
the assembly relative to the position of materials providing
thermal resistance shall be determined according to Part 5,
where
a)the intended use of the interior space requires the indoor relative humidity to be maintained above 35% over the heating season and the ventilating and air-conditioning system is designed to maintain that relative humidity, or
b)the intended use of the interior space will result in an average monthly indoor relative humidity above 35% over the heating season and the ventilating and air-conditioning system does not have the capacity to reduce the average monthly relative humidity to 35% for any period over that period.
5) Where the mild climate indicator, determined in
accordance with Sentence (6), is less than or equal to 6 300, the position of low air- and vapour-permeance materials
within the assembly relative to the position of materials
providing thermal resistance shall be determined according
to Part 5, where
a)the intended use of the interior space requires the indoor relative humidity to be maintained above 60% over the heating season and the ventilating and air-conditioning system is designed to maintain that relative humidity, or
b)the intended use of the interior space will result in an average monthly indoor relative humidity above 60% over the heating season and the ventilating and air-conditioning system does not have the capacity to reduce the average monthly relative humidity to 60% over that period.
6) The mild climate indicator (MCI) shall be
calculated according to the following formula:
where
| abs (2.5% JMT) | = absolute value of 2.5% January mean temperature, and |
| DD | = degree-days |
7) For walls, the air space described in Clause (2)(c) shall comply with Clause 9.27.2.2.(1)(a).
1) All walls, ceilings and floors separating heated space from unheated space, the exterior air or the exterior soil shall be provided with sufficient thermal insulation to prevent moisture condensation on their room side during the winter and to ensure comfortable conditions for the occupants. (See A-9.1.1.1.(1) in Appendix A.) (See Part 10)
2) Alternatives to the requirements of Table 9.25.2.1. may be determined through the use of energy consumption estimation computer modeling or using other acceptable good engineering principles.
[Rev. 2, B.C. Reg. 73/2008.]
1) Except as required in Sentence (2), thermal insulation shall conform to the requirements of
a)CAN/CGSB-51.25-M, “Thermal Insulation, Phenolic, Faced,”
b)CGSB 51-GP-27M, “Thermal Insulation, Polystyrene, Loose Fill,”
c)CAN/ULC-S701, “Thermal Insulation, Polystyrene, Boards and Pipe Covering,”
d)CAN/ULC-S702, “Mineral Fibre Thermal Insulation for Buildings,”
e)CAN/ULC-S703, “Cellulose Fibre Insulation (CFI) for Buildings,”
f)CAN/ULC-S704, “Thermal Insulation, Polyurethane and Polyisocyanurate, Boards, Faced,”
g)CAN/ULC-S705.1, “Thermal Insulation – Spray Applied Rigid Polyurethane Foam, Medium Density – Material - Specification,” or
h)CAN/ULC-S706, “Wood Fibre Thermal Insulation for Buildings.”
2) The flame-spread ratings requirements contained in the standards listed
in Sentence (1) shall not apply. (See Appendix A.)
3) Insulation in contact with the ground shall be inert
to the action of soil and water and shall be such that its insulative properties are not
significantly reduced by moisture.
1) Insulation shall be installed so that there is a
reasonably uniform insulating value over the entire face of the
insulated area.
2) Insulation shall be applied to the full width and
length of the space between furring or framing.
3) Except where the insulation provides the principal
resistance to air leakage, thermal insulation shall be installed
so that at least one face is in full and continuous contact with
an element with low air permeance.
4) Insulation on the interior of foundation walls enclosing a crawl space shall be applied so that there is not
less than 50 mm clearance above the crawl space floor, if the
insulation is of a type that may be damaged by water.
5) Insulation around concrete slabs-on-ground shall be
located so that heat from the building is not restricted from reaching the ground beneath the perimeter, where exterior walls are not supported by
footings extending below frost level.
6) Where insulation is exposed to the weather and subject
to mechanical damage, it shall be protected with not less than
a)6 mm asbestos-cement board,
b)6 mm preservative-treated plywood, or
c)12 mm cement parging on wire lath applied to the exposed face and edge.
7) Insulation located in areas where it may be subject to
mechanical damage shall be protected by a covering such as
gypsum board, plywood, particleboard, OSB, waferboard or
hardboard.
8) Insulation in factory-built buildings shall be installed so that it will not become dislodged during
transportation.
9) Deleted.
[Rev. 2, B.C. Reg. 73/2008.]
1) Except as provided in Sentences (2) to (6), loose-fill insulation shall be used on horizontal surfaces only.
2) Where loose-fill insulation is installed in an
unconfined sloped space, such as an attic space over a sloped
ceiling, the supporting slope shall not be more than
a)4.5 in 12 for mineral fibre or cellulose fibre insulation, and
b)2.5 in 12 for other types of insulation.
3) Loose-fill insulation is permitted to be used in
wood-frame walls of existing buildings. (See Appendix A.)
4) Where blown-in insulation is installed in above-ground
or below-ground wood-frame walls of new buildings,
a)the density of the installed insulation shall be sufficient to preclude settlement,
b)the insulation shall be installed behind a membrane that will permit visual inspection prior to the installation of the interior finish,
c)the insulation shall be installed in a manner that will not interfere with the installation of the interior finish, and
d)no water shall be added to the insulation, unless it can be shown that the added water will not adversely affect other materials in the assembly.
5) Water repellent loose-fill insulation is permitted to
be used between the outer and inner wythes of masonry cavity walls. (See Appendix A.)
6) Where soffit venting is used, measures shall be taken
a)to prevent loose-fill insulation from blocking the soffit vents and to maintain an open path for circulation of air from the vents into the attic or roof space, and
b)to minimize airflow into the insulation near the soffit vents to maintain the thermal performance of the material. (See Article 9.19.1.3.)
1) Spray-applied polyurethane insulation shall be
installed in accordance with CAN/ULC-S705.2, “Thermal
Insulation – Spray-Applied Rigid Polyurethane Foam, Medium
Density, Installer's Responsibilities –
Specification.”
1) Thermally insulated wall, ceiling and floor assemblies
shall be constructed so as to include an air barrier system that will provide a continuous barrier to air leakage
a)from the interior of the building into wall, floor, attic or roof spaces, sufficient to prevent excessive moisture condensation in such spaces during the winter, and
b)from the exterior inward sufficient to prevent moisture condensation on the room side during winter and to ensure comfortable conditions for the occupants.
(See Appendix A.)1) Air barrier systems shall possess the characteristics necessary to provide an effective
barrier to air infiltration and exfiltration under differential
air pressure due to stack effect, mechanical systems or wind.
2) Where polyethylene sheet is used to provide
airtightness in the air barrier system, it shall conform to CAN/CGSB-51.34-M, “Vapour
Barrier, Polyethylene Sheet for Use in Building
Construction.”
1) Where the air barrier system consists of an air-impermeable
panel-type material, all joints shall be sealed to prevent air
leakage.
2) Where the air barrier system consists of flexible sheet material,
all joints shall be
a)sealed, or
b)lapped not less than 100 mm and clamped, such as between framing members, furring or blocking and rigid panels.
3) Where an interior wall meets an exterior wall,
ceiling, floor or roof required to be provided with air barrier
protection, the air barrier system shall extend across the intersection.
4) Where an interior wall projects through a ceiling or
extends to become an exterior wall, spaces in the wall shall be
blocked to provide continuity across those spaces with the air barrier system in the abutting walls or ceiling.
5) Where an interior floor projects through an exterior
wall or extends to become an exterior floor, continuity of the
air barrier system shall be maintained from the abutting walls across
the floor assembly.
6) Penetrations of the air barrier system, such as those created by the installation of doors, windows, electrical wiring, electrical
boxes, piping or ductwork, shall be sealed to maintain the
integrity of the air barrier system over the entire surface.
7) Access hatches installed through assemblies
constructed with an air barrier system shall be weatherstripped around their
perimeters to prevent air leakage.
8) Clearances between chimneys or gas vents and the surrounding construction that would
permit air leakage from within the building into a wall or attic or roof space shall be sealed by noncombustible material to prevent such leakage.
1) Thermally insulated wall, ceiling and floor assemblies
shall be constructed with a vapour barrier so as to provide a barrier to diffusion of water vapour from the interior into wall spaces,
floor spaces or attic or roof spaces.
1) Except as provided in Sentences (2) and (3), vapour barriers shall have a permeance not greater than 60 ng/(Pa•s•m2)
measured in accordance with ASTM E 96, “Water Vapor
Transmission of Materials,” using the desiccant
method (dry cup).
2) Where the mild climate indicator, determined in
accordance with Sentence 9.25.1.2.(6), is greater than 6 300, vapour barriers shall be designed according to Part 5, where
a)the intended use of the interior space requires the indoor relative humidity to be maintained above 35% over the heating season and the ventilating and air-conditioning system is designed to maintain that relative humidity, or
b)the intended use of the interior space results in an average monthly indoor relative humidity above 35% over the heating season and the ventilating and air-conditioning system does not have the capacity to reduce the average monthly relative humidity to 35% or less over that period.
(See A-9.25.1.2. in Appendix A.)3) Where the mild climate indicator, determined in
accordance with Sentence 9.25.1.2.(6), is less than or equal to 6 300, vapour barriers shall be designed according to Part 5, where
a)the intended use of the interior space requires the indoor relative humidity to be maintained above 60% over the heating season and the ventilating and air-conditioning system is designed to maintain that relative humidity, or
b)the intended use of the interior space results in an average monthly indoor relative humidity above 60% over the heating season and the ventilating and air-conditioning system does not have the capacity to reduce the average monthly relative humidity to 60% over that period.
(See A-9.25.1.2. in Appendix A.)4) Where polyethylene is installed to serve only as
the vapour barrier, it shall comply with Clause 4.4, Thermal Stability, and
Clause 5.7, Oxidative Induction Time, of CAN/CGSB-51.34-M, “Vapour Barrier,
Polyethylene
Sheet for Use in Building Construction.”
5) Membrane-type vapour barriers other than polyethylene shall conform to the
requirements of CAN/CGSB-51.33-M, “Vapour Barrier Sheet, Excluding
Polyethylene, for Use in Building Construction.”
6) Where a coating is applied to gypsum board to function
as the vapour barrier, the permeance of the coating shall be determined in accordance
with CAN/CGSB-1.501-M,
“Method for Permeance of Coated Wallboard.”
1) Vapour barriers shall be installed to protect the entire surfaces of thermally insulated
wall, ceiling and floor assemblies.
2) Vapour barriers shall be installed sufficiently close to the warm side of insulation to
prevent condensation at design conditions. (See Appendix A.)