M&G DuraVent DuraTech® 5-8 - Manual (Page 9)

9
Table 2
Figure 10
Figure 8
FRAMING
FIRESTOP
RADIATION SHIELD
Figure 9
TWIST CLOCKWISE
TO TIGHTEN
ATTIC INSULATION
SHIELD
Framing Dimensions
Chimney Diameter
5” 6” 7” 8”
Cathedral Ceiling
Support Box 11-1/4” 12-1/4” 13-1/4” 14-1/2”
Flat Ceiling
Support Box 11-1/4” 12-1/4” 13-1/4” 14-1/2”
round Ceiling
Support Box 11-1/4” 12-1/4” 13-1/4” 14-1/4”
FireStop radiation
Shield 11-1/4” 12-1/4” 13-1/4” 14-1/4”
Wall thimBle 11-1/4” 12-1/4” 13-1/4” 14-1/4”
CaS Ceiling
Support na 12-1/4” na 14-1/2”
CaS Wall thimBle na 12-1/4” na 14-1/4”
reduCed
ClearanCe
Support Box na 10-1/4” na na
above that where the Support Box is located.
Example: in a multistory home where the
appliance is on the ground floor (Support
Box is in the 1st floor ceiling), you would
need a Firestop Radiation Shield at the 2nd
floor ceiling, and at the 3rd floor ceiling, etc.,
including where the chimney penetrates into
the attic. Figure 7 shows a typical 2-story
installation with an attic.
Note: a Firestop Radiation Shield is not
installed where the chimney penetrates
through the roof. The Firestop Radiation
Shield is installed on the underside of the
ceiling/floor framing, with the cylindrical
“tube” portion of the shield pointing
upward. (Fig 8). Use a minimum of either
(1) 8 penny nail or (1) #8, 1-1/2” wood screws
per corner. Refer to Table 2 for framing
requirements.
opening and maintain the 2-inch clearance to
combustibles.
6. Install Firestop Radiation Shield: A
Firestop Radiation Shield is required in
multistory installations at each floor penetration