OBC VOLUME 2 · SUPPLEMENTARY STANDARD SB-9Updated for the 2024 Ontario Building Code
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SB-9 — Requirements for Soil Gas Control
Supplementary Standard SB-9 ("Requirements for Soil Gas Control") forms part of Volume 2 of the 2024 Ontario Building Code. The full text is reproduced below with a linked table of contents.
2024MMAH Supplementary Standard SB-9
SB-9 Requirements for Soil Gas
Control (See Appendix A)
Section 1 Soil Gas Control in Masonry Walls
1.1.Sealing of Masonry Walls
(1) Masonry walls required to provide a barrier to soil gas ingress shall
(a) include a course of masonry units without voids, or
(b) be sealed with flashing material extending across the full width of the masonry.
(2) The masonry course or flashing described in Sentence (1) shall
(a) be located at the level of the adjoining floor and be sealed to it in accordance with Subsection 3.3., or
(b) in the absence of a floor, be located at the level of the ground cover required by Article 9.18.6.1. of Division B of
the Building Code and be sealed to it.
Section 2 Soil Gas Control in Underground Roofs
2.1.Sealing of Underground Roofs
(1) Waterproofing systems for roofs of underground structures shall be sealed to the soil gas barrier in the walls.
Section 3 Soil Gas Control in Floors
3.1.Soil Gas Barriers in Floors
(1) Except as required in this Section, where the floor-on-ground is a concrete slab, the soil gas barrier shall conform to
Articles 9.13.2.6., 9.25.3.2. and 9.25.3.3. of Division B of the Building Code and be
(a) installed below the slab, or
(b) applied to the top of the slab, provided a separate floor is installed over the slab.
(2) Where the soil gas barrier is sheet material installed below a slab-on-ground, joints in the barrier shall be lapped not
less than 300 mm.
(3) Where the soil gas barrier is installed above a slab-on-ground, joints in the barrier shall be sealed.
(4) Where installed in conjunction with a framed floor-on-ground, the soil gas barrier shall be installed in accordance
with Articles 9.13.2.6., 9.25.3.2. and 9.25.3.3. of Division B of the Building Code.
3.2.Sealing of the Perimeter and Penetrations
(1) A floor-on-ground shall be sealed around its perimeter to the inner surfaces of adjacent walls using flexible sealant.
(2) All penetrations of a floor-on-ground by pipes or other objects shall be sealed against soil gas leakage.
(3) All penetrations of a floor-on-ground that are required to drain water from the floor surface shall be sealed in a
manner that prevents the upward flow of soil gas without preventing the downward flow of liquid water.
Page 2 • SB-9
2024MMAH Supplementary Standard SB-9
Appendix A to SB-9
A-SB-9 Requirements for Soil Gas Control
Soil Gas Control.
The requirements for Soil Gas Control in Walls, Soil Gas Barriers, and Sealing of the Perimeter and Penetrations, are
illustrated in the following drawings. Sealing of penetrations of the slab also applies to hollow metal and masonry
columns. Not only the perimeters but also the centres of such columns must be sealed or blocked.
Figure SB-9A
Dampproofing and Soil Gas Control at Foundation Wall/Floor Junctions with Solid Walls
The requirement regarding drainage openings in slabs can be satisfied with any of a number of proprietary devices which
prevent soil gas entry through floor drains. Some types of floor drains incorporate a trap which is connected to a nearby
tap so that the trap is filled every time the tap is used. This is intended to prevent the entry of sewer gas but would be
equally effective against the entry of soil gas.
Figure SB-9B
Dampproofing and Soil Gas Control at Foundation Wall/Floor Junctions with Hollow Walls
There are two primary purposes for excluding soil gas:
• Sealing the interface between the soil and the occupied space, so far as is reasonably practicable, and
• Ensuring that the pressure difference across the soil/space interface is positive (i.e., towards the outside) so that
inward soil gas flow through any remaining leaks will be prevented.
Effective Depressurization.
To allow effective depressurization of the space between the gas barrier and the ground, the extraction opening (the pipe)
should not be blocked and should be arranged such that air can be extracted from the entire space between the gas barrier
and the ground. This will ensure that the extraction system can maintain negative pressure underneath the entire floor (or
in heated crawl spaces underneath the air barrier). The arrangement and location of the extraction system inlets(s) may
have design implications where the footing layout separates part of the space underneath the floor.
2024MMAH Supplementary Standard SB-9
Radon Testing and Active Depressurization Systems.
Where radon concentration testing is carried out, it should be done in accordance with HC Pub. 4171, "Guide for Radon
Measurements in Residential Dwellings (Homes), 2008", to determine the radon concentration in the building. The
sampling should include basement concentration measurements . If the average annual radon concentration determined
exceeds 200 Bq/m3 in the normal occupancy area, measures, such as the conversion of rough-in system to an active
subfloor depressurization system, need to be taken to reduce the radon concentration to a level below 200 Bq/m 3 in the
normal occupancy area.
Where an active subfloor depressurization system is installed, the following needs to be taken into consideration:
1. provision to provide makeup air in accordance with Article 9.32.3.8. of Division B of the Building Code, and
2. measures to ensure that any resultant decrease in soil temperature will not adversely affect the foundation.
Figure SB-9C
Acceptable Configurations for the Extraction Opening in a Depressurization System
Page 4 • SB-9
Ministry of Municipal Affairs
Building and Development Branch
MMA Supplementary Standard SB-10
MMA Supplementary Standard SB-10
Energy Efficiency Requirements
December 22, 2016 update
2024MMA Supplementary Standard SB-10
COMMENCEMENT
MMA Supplementary Standard SB-10 comes into force on the 1st day of January, 2025.
EDITORIAL
e1 Editorial correction issued for January 1, 2025.
ACKNOWLEDGEMENT
The Ministry wishes to thank ASHRAE for permission to reproduce material from
ANSI/ASHRAE/USGBC/IES Standard 189.1-2009.
© Copyright
©
Copyright King’s Printer for Ontario 2024
All rights reserved.
Questions regarding copyright, including reproduction and distribution, may be directed to the Director,
Building and Development Branch of the Ministry of Municipal Affairs and Housing.
2024MMA Supplementary Standard SB-10
NOMENCLATURE
This Supplementary Standard is organized into a hierarchy of Divisions, Chapters, Parts or Sections, Subsections, Articles,
Sentences, Clauses and Subclauses.
e1 FOREWORD
This edition of SB-10 is still the same edition released on December 22, 2016 except that the requirements applicable on or
before December 31, 2016 have been removed and marked as “Reserved”.
This Supplementary Standard contains 5 Divisions as follows:
Division 1 addresses general requirements. This updated Supplementary Standard includes new referenced standards and
updated versions of previously referenced standards.
Division 2 is reserved.
Division 3 contains requirements for the design and construction of buildings for which a permit has been applied for after
December 31, 2016. In this updated Supplementary Standard, Division 3 has been substantially revised. The existing sample
compliance path has been replaced by new compliance paths. The compliance paths are based on contemporary energy codes
and standards and contain additional requirements to achieve, on average, a 13 percent improvement over the efficiency level
required by Sentence 12.2.1.1.(2) of Division B of O. Reg. 332/12 (2012 Building Code) as it read on December 31, 2024.
Division 3 contains a transition provision and revised CO2e factors in Chapter 1 as well as the following three compliance
paths based on:
1. ANSI/ASHRAE/IES Standard 90.1-2013, “Energy Standard for Buildings Except Low-Rise Residential Buildings”, and
additional requirements introduced through Chapter 2,
2. CCBFC NRCC 56191, “2015 National Energy Code of Canada for Buildings” and additional requirements introduced
through Chapter 3, and
3. ANSI/ASHRAE/USGBC/IES Standard 189.1-2014, “Standard for the Design of High-Performance Green Buildings
Except Low-Rise Residential Buildings”.
Division 3 also describes limitations on peak electric demand and annual carbon dioxide emissions.
Division 4 is reserved.
Division 5 contains simplified energy efficiency requirements for the construction of certain non-residential buildings
within the scope of Part 9 of Division B of the 2012 Building Code for which a permit has been applied for after
December 31, 2016. Division 5 was revised consistent with changes made to Division 3 in this updated edition.
The application of the above documents to existing buildings is limited to the requirements of Part 10 and Part 11 of
Division B of the Building Code.
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Code text is reproduced for reference from the Ontario Building Code (O. Reg. 163/24, 2024 Building Code Compendium). This page is provided for general information and is not an official copy. Always verify requirements against the official Ontario Building Code and confirm with your local building department.