Desa SDVBND Owner's Operation And Installation Manual page 17

VENTING INSTALLATION
Continued
6. Continue to add pipe sections until the height of the vent cap
meets the minimum building code requirements described in
Figure 20 on page 11. Note : You must increase vent height for
steep roof pitches. Nearby trees, adjoining rooflines, steep
pitched roofs, and other similar factors may cause poor draft
or down-drafting in high winds. Increasing the vent height may
solve this problem.
7. Twist-lock the vent cap onto the last section of vent pipe and
seal outer pipe connection with high temperature silicone seal-
ant as specified in the second warning statement on page 12.
Note: If the vent pipe passes through any occupied areas above the first
floor, including storage spaces and closets, you must enclose pipe. You
may frame and sheetrock the enclosure with standard construction
material. Make sure and meet the minimum allowable clearances to
combustibles. Do not fill any of the required air spaces with insulation.
Cathedral Ceiling Installation
1. Remove shingles or other roof covering as necessary to cut the
rectangular hole for the support box. Mark the outline of the
cathedral ceiling support box on the roof sheathing using the
locating hole as a center point.
2. Cut the hole 1/8" larger than the support box outline (see
Figure 33).
3. Lower the support box through the hole in the roof until the
bottom of the box extends at least 2" below the ceiling (see
Figure 33). Align the support box vertically and horizontally
using a level. Temporarily tack the support box in place through
the inside walls and into the roof sheathing.
4. Using tin snips, cut the support box from the top corners down
to the roofline and fold the resulting flaps over the roof sheath-
ing (see Figure 34). Apply a bead of nonhardening mastic around
the top edges of the support box to make a seal between the box
and the roof. Nail in place with roofing nails. Remove any com-
bustible material that might be inside of the support box.
5. Complete the cathedral ceiling installation by following the same
procedures outlined in steps 2 through 7 for Flat Ceiling Instal-
lation, page 16 .
Level
Cut hole 1/8" larger than support
box when projected onto roofline
Figure 33 - Cathedral Ceiling Support Box Installation
For more information, visit www.desatech.com
For more information, visit www.desatech.com
112126-01B
Cathedral Ceiling
Support Box
2" minimum
below finished
ceiling
VENTING INSTALLATION
Installation for Vertical Termination (Cont.)
Figure 34 - Installed Cathedral Ceiling Support Box
Vertical Termination Configurations
Figure 35 through 38 show four different configurations for vertical
termination. All connections must be sealed with high temperature
silicone sealant as specified in the second warning statement on
page 12.
Figure 35 - Vertical Venting Configuration Using Two 90
Nonhardening mastic under
all edges of support box
before nailing
Venting with Two 90 ° Elbow
Vertical (V) Horizontal (H)
5' min. 2' max.
6' min. 4' max.
7' min. 6' max.
8' min. 8' max.
20' max. 8' max.
Note: Install restrictor
into 4" collar of burner
system as shown.
17
17
°
Elbow