Enviro EG40-070 owner manual Use of Wall Straps

Initial Installation

QUALIFIED INSTALLERS ONLY

support straps to the roof. Seal the nails holes heads with non-hardening mastic. Trim the excess length of the support straps that extend out beyond the edge of the flashing.

7.Slip the flashing over the pipe section protruding through the roof. Secure the base of the flashing to the roof with roofing nails. Use a non-hardening sealant between the uphill edge of the flashing and the roof. Insure the roofing material overlaps the top edge of the flashing as shown in Figure 30. Verify that you have at least the minimum clearance to combustibles at the roof line.

8.Continue to add pipe sections until the height of the vent cap meets the minimum code requirements. Refer to Figure 31 and Table 5. Note that for steep roof pitches, the vent height must be increased. In high wind conditions, nearby trees, adjoining roof lines, steep pitched roofs, and other similar factors can result in poor draft, or down drafting. In these cases, increasing the vent height may solve the problem.

9.Slip the storm collar over the pipe, and push it down to the top of the roof flashing as shown in Figure

30.Use the non-hardening sealant around the joint between the pipe and the storm collar.

10.Twist-lock the vent cap.

Figure 31: Height of Vertical Termination;

Reference Table 5.

Table 5: Minimum ‘H’ for Figure 31.

Roof Pitch	Minimum Height
	Ft	Meters
Flat to 7/8	1	0.3
Over 7/12 to 8/12	1.5	0.46
Over 8/12 to 9/12	2	0.61
Over 9/12 to 10/12	2.5	0.76
Over 10/12 to 11/12	3.25	0.99
Over 11/12 to 12/12	4	1.22
Over 12/12 to 14/12	5	1.52
Over 14/12 to 16/12	6	1.83
Over 16/12 to 18/12	7	2.13
Over 18/12 to 20/12	7.5	2.29
Over 20/12 to 21/12	8	2.44

NOTES:

•If an offset is necessary in the attic to avoid obstructions, it is important to support the vent pipe every 3 ft (91 cm), to avoid excessive stress on the elbows, and possible separation. Wall straps are available for this purpose (see Figure 32).

•When ever possible, use 45° degree elbows instead of 90° degree elbows. The 45° degree elbow offers less restriction to the flow of flue gases and intake air.

Figure 32: Use of Wall Straps.

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