The Ontario Building Code | Thickness, Rating and Material Standards

9.23.16.2. Thickness, Rating and Material Standards

(1) Where wall sheathing is required for the purpose of complying with this Section, it shall conform to Table 9.23.16.2.A. or Table 9.23.16.2.B.

Table 9.23.16.2.A.
wall Sheathing Thickness and Specifications

Forming Part of Sentence 9.23.16.2.(1)

Item

Column 1

Type of Sheathing

Column 2

Minimum Thickness, mm(1)

With supports 406 mm o.c.

Column 3

Minimum Thickness, mm(1)

With supports 610 mm o.c.

Column 4

Material Standards

1.

Fibreboard (insulating)

9.5

11.1

CAN/ulc-S706

2.

gypsum Sheathing

9.5

12.7

CAN/CSA-A82.27-M

ASTM C1177 / C1177M

ASTM C1396 / C1396M

3.

Lumber

17.0

17.0

See Table 9.3.2.1.

4.

Mineral Fibre, Rigid Board, Type 2

25

25

CAN/ulc-S702

5.

OSB, O-2 Grade

6.0

7.5

CSA O437.0

6.

OSB, O-1 Grade, and waferboard, R-1 Grade

6.35

7.9

CSA O437.0

7.

Phenolic, faced

25

25

CAN/cgsb-51.25-M

8.

Plywood (exterior type)

6

7.5

CSA O121

CSA O151

CSA O153-M

9.

Polystyrene, Types 1 and 2

38

38

CAN/ulc-S701

10.

Polystyrene, Types 3 and 4

25

25

CAN/ulc-S701

11.

Polyurethane and Polyisocycanurate Type 1, faced

38

38

CAN/ulc-S704

12.

Polyurethane and Polyisocycanurate Types 2 and 3, faced

25

25

CAN/ulc-S704

Notes to Table 9.23.16.2.A.:

(1) See also Sentences 9.27.5.1.(2) to (4).

Table 9.23.16.2.B.
Rating For wall Sheathing When Applying CSA O325

Forming Part of Sentence 9.23.16.2.(1)

Item

Column 1

Maximum Spacing of supports, mm

Column 2

panel Mark

1.

406

W16

2.

508

W20

3.

610

W24