Sapphire Audio DV425TR Manual De Usuario

02/01                                                                                     Page 37                                                                               250-5533

 

Follow installation Steps 1 and 2 under 

vertical termination section.

 

Using the plumb-bob, mark the centerline of 

the venting system on the ceiling, and drill a small 

hole through the ceiling and roof at this point. From 

the roof, locate the drill hole and mark the outline of 

the cathedral ceiling support box.

 

Remove shingles or other roof covering as 

necessary to cut the rectangular hole for the support 

box. Cut the hole 1/8” (3mm) larger than the support 

box outline.

 

Lower the support box through the hole in the 

roof until the bottom of the box protrudes at least 

2” (51mm) below the ceiling (Figure 17). Align the 

support box both vertically and horizontally with a 

level. Temporarily tack the support box in place 

through the inside walls and into the roof sheathing.

 

Using tin snips, cut the support box from the 

top corners down to the roofline, and fold the resulting 

flaps over the roof sheathing (Figure 18). Before 

nailing it to the roof, run a bead of non-hardening 

mastic around the top edges of the support box to 

make a seal between it and the roof.  Clean out any 

combustible material from inside the support box.

 

Complete the cathedral ceiling installation by 

following the same procedures outlined in steps 4 

through 8 for vertical terminations.