8Vent Clearances and Framing
A. Pipe Clearances to Combustibles
WARNING! Risk of Fire! Maintain air space clearance to vent. DO NOT pack insulation or other combustibles:
•Between ceiling restops
•Between wall shield restops
•Around vent system
Failure to keep insulation or other material away from vent pipe may cause over heating and re.
3 in. |
|
|
(76 mm) |
| Air space clearance to |
Drywall |
| bottom and sides of |
| horizontal pipe must be | |
|
| at least 1 in. (25 mm) |
1 in. (25 mm) |
|
|
minimum |
|
|
2 x 4 or |
| No combustible |
2 x 6 |
| framing to be |
header |
| located within |
|
| shaded area. |
| WALL | |
| minimum to | |
| perpendicular | |
|
| |
|
| wall. |
B. Wall Penetration Framing
Combustible Wall Penetration
Whenever a combustible wall is penetrated, you must frame a hole for the wall shield restop(s). The wall shield restop maintains minimum clearances and prevents cold air in ltration.
•The opening must be framed on all four sides using the same size framing materials as those used in the wall construction.
•A wall shield restop is required on one side only on interior walls. If your local inspector requires a wall shield restop on both sides, then both wall shield restops must have a heat shield attached to them.
•See Section 10.I. for information for regarding the installation of a horizontal termination cap.
Non-Combustible Wall Penetration
If the hole being penetrated is surrounded by noncombus- tible materials such as concrete, a hole with diameter one inch greater than the pipe is acceptable.
Whenever a
Figure 8.1 Horizontal Venting Clearances To Combustible Materi- als
12in.
(305 mm)
The center of the framing hole is
1 in. [25 mm] above the center of the horizontal vent pipe.
Framing should be constructed of 2 X 4 lumber or heavier.
10 in.
(254 mm)
Vent framing hole.
* Center of pipe
(2604 mm)*
Figure 8.2 Wall Penetration
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