Plumber’s Tape connected to Wall Strap
Wall Strap
Two 45˚ Elbows
Figure 5.12
Step 3.
To install the round support box/wall thimble cover in a flat ceiling, cut a 10 in. (254mm) square hole in the ceiling, centered on the hole drilled in Step 2. Frame the hole as shown in Figure 5.13.
Ceiling
Joists
Framing
1 - 1/2 in. (38mm) Long
Wood Screws
Figure 5.13
Step 4.
Assemble the desired lengths of pipe and elbows necessary to reach from the appliance up through the round support box. Ensure that all pipe and elbow connections are in their fully
Step 5.
Cut a hole in the roof centered on the small drill hole placed in the roof in Step 2. The hole should be of sufficient size to meet the minimum requirements for clearance to combustibles, as
specified. Continue to assemble lengths of pipe and elbows necessary to reach from the ceiling support box/wall thimble up through the roof line. Galvanized pipe and elbows may be utilized in the attic, as well as above the roofline. The galvanized finish is desirable above the roofline, due to its higher corrosion resistance.
NOTE:
(1) If an offset is necessary in the attic to avoid obstructions, it is important to support the vent pipe every 3 ft. (914mm) to avoid excessive stress on the elbows, and possible separation. Wall straps are available for this purpose, Figure 5.12.
(2)Whenever possible, use 45° elbows, instead of 90° elbows. The 45° elbow offers less restriction to the flow of flue gases and intake air.
Step 6.
Slip the flashing over the pipe section(s) protruding through the roof. Secure the base of the flashing to the roof with roofing nails. Ensure the roofing material overlaps the top edge of the flashing as shown in Figure 5.14. Verify that the chimney is the required height above the roof. See roof pitch table, Figure 4.3, on page 8 of this manual.
Shingles overlap on | CAP AND STORM | |
COLLAR NOT SHOWN | ||
top edge of flashing | ||
FOR CLARITY | ||
|
Figure 5.14
Step 7.
Continue to assemble pipe sections until the height of the vent (before adding the termination cap) meets the minimum code requirements as outlined in the current
Page 16 | July 29, 2008 |