G.Vertical Termination
1. Direct Vent Pipe
Vertical Termination Cap
Storm Collar 
Flashing
Firestop
Support Box
Pipe Length
Figure 5.10
Step 1.
Check the installation instructions for required 1 in. (25mm) clearances (air space) to combustibles when passing through ceilings, walls, roofs, enclosures, attic rafters, or other nearby combustible surfaces. See page 16, Figure
5.15.Check the instructions for maximum vertical rise of the venting system, and any maximum horizontal offset limitations. All offsets must fall within the set parameters of the vent graph (Figure 5.2) located on page 11.
NOTE: Maximum vertical rise allowable is 35 ft. (11m) Figure 5.11).
NOTE: Maximum number of 45° elbows permitted for a vertical installation is eight, provided their installation does not decrease maximum allowable horizontal run (as specified by vent graph, on page 11).
WARNING
Fire Risk. Explosion Risk.
Maintain vent clearance to combustibles as speci- fied.
• Do not pack air space with insulation or other materials.
Failure to keep insulation or other materials away from vent pipe may cause fire.
35 ft. (11m) 
Maximum
Figure 5.11
Step 2.
Set the gas appliance in its desired location. Drop a plumb bob down from the ceiling to the position of the appliance flue exit, and mark the location where the vent will penetrate the ceiling. Drill a small hole at this point. Next, drop a plumb bob from the roof to the hole previously drilled in the ceiling, and mark the spot where the vent will penetrate the roof. Determine if ceiling joists, roof rafters, or other framing will obstruct the venting system. You may wish to relocate the appliance, or to offset, as shown in Figure 5.12 to avoid cutting loadbearing members. When location is determined, drill small hole.
Plumber’s Tape connected to Wall Strap
Wall Strap
Two 45˚ Elbows
Figure 5.12
September 1, 2008 | Page 15 |
