Desa VDDVF36STN/STP, VDDVF36PN/PP Flat Ceiling Installation, Cathedral Ceiling Installation

VENTING INSTALLATION

Installation For Vertical Termination (Cont.)

13

VENTING INSTALLATION

Continued

Roof

Flashing

Wall Strap

45° Elbow

Ceiling Firestop

Figure 24 - Offset with Wall Strap and 45° Elbows

Flat Ceiling Installation

1.Cut a 10" square hole in the ceiling using the locating hole as a center point. The opening should be framed to 10"x10" (25.4cm x 25.4cm) inside dimensions, as shown in Figure 17 on page 11 using framing lumber the same size as the ceiling joists. If the area above the ceiling is an insulated ceiling or a room, nail firestop from the top side. This prevents loose insulation from falling into the required clearance space. Otherwise, install firestop below the framed hole. The firestop should be installed with no less than three nails per side (see Figure 25).

2.Assemble the desired lengths of pipe and elbows necessary to reach from the fireplace flue up through the firestop. All connections must be sealed with high temperature silicone sealant as specified in the second warning statement on page 9. Be sure all pipe and elbow connections are fully twist-locked (see Figure 16, page 10).

3.Cut a hole in the roof using the locating hole as a center point. (Cover any exposed open vent pipes before cutting hole in roof.) The 10"x10" (25.4cm x 25.4cm) hole must be measured on the horizontal; actual length may be larger depending on the pitch of the roof. There must be a 1" clearance from the vent pipe to combustible materials. Frame the opening as shown in Figure 17 on page 11.

If area above is a room, install	If area above is not a room, install
firestop above framed hole.	firestop below framed hole.

4.Connect a section of pipe and extend up through the hole. Note: If an offset is needed to avoid obstructions, you must support the vent pipe every 3 feet (91.4cm). Use wall straps for this purpose (see Figure 24). Whenever possible, use 45° elbows instead of 90° elbows. The 45° elbow offers less re- striction to the flow of the flue gases and intake air.

5.Place the flashing over the pipe section(s) extending through the roof. Secure the base of the flashing to the roof and framing with roofing nails. Be sure roofing material overlaps the top edge of the flashing as shown in Figure 24. There must be a 1" (2.5cm) clearance from the vent pipe to combustible materials.

6.Continue to add pipe sections until the height of the vent cap meets the minimum building code requirements described in Figure 13 on page 8. 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 with high temperature silicone sealant as specified in the second warning statement on page 9.

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" (0.3cm) larger than the support box outline (see Figure 26).

3.Lower the support box through the hole in the roof until the bottom of the box extends at least 2" (5.1cm) below the ceil- ing (see Figure 26). Align the support box vertically and hori- zontally using a level. Temporarily tack the support box in place through the inside walls and into the roof sheathing.

Level

Cathedral ceiling support box

	2" (5.1cm)
	minimum
Cut hole 1/8" (0.3cm) larger	below
than support box when	finished
	ceiling
projected onto roofline

Figure 25 - Installing Firestop Figure 26 - Cathedral Ceiling Support Box Installation

For morevisit www..com

106918-01B