(a) Subflooring may be one-inch sheathing laid diagonally or at right angles to floor joists, securely nailed to all bearings.
(b) Plywood panels shall be applied continuously over two or more spans with the direction of face grain perpendicular to supports. The allowable spans shall be as follows:
Panel Identification Maximum Joist
Index | Spacing
|
30/12
| 12 inches
|
32/16
| 16 inches
|
36/16
| 16 inches
|
42/20
| 20 inches
|
48/24
| 24 inches
|
1-1/8" Group 1 & 2
| 48 inches
|
1-1/4" Group 3 & 4
| 48 inches
|
(c) A suitable underlayment shall be installed when the finished flooring is resilient flooring, tile or carpeting. Plywood shall be three-eighths of an inch interior UNDERLAYMENT, grade C-C plugged, or any other sanded grade exterior type of plywood. A separate underlayment layer may be omitted when a plywood combination subfloor/underlayment is installed in accordance with subsection (d) hereof.
(d) If resilient flooring, tile or carpeting is to be applied to a plywood subfloor without a separate underlayment layer, the plywood grades shall be as described above in subsection (c) hereof. The minimum thickness of plywood shall comply with the following table. However, a plywood with T & G edges (five-eighths of an inch or thicker) shall be used, or solid blocking under all unsupported edges shall be provided, unless the finished floor is 25/32 of an inch wood strip.
Species Groups | Maximum Spacing of Joists (in.) | ||
16 | 16 | 20 | 24 |
1 | ½ | 5/8 | 3/4 |
2 & 3 | 5/8 | 3/4 | 7/8 |
4 | 3/4 | 7/8 | 1 |
(Ord. 42-1981. Passed 2-23-81.)