Roof Penetration; Install Chase/Chase Top - Majestic Ashland ASH42 Series Installation Manual

G. Roof Penetration
• Refer to Figure 5.9.
• Plumb from roof to center of chimney.
• Drive a nail up through roof to mark center of pipe.
• Measure to either side of nail and mark the 17 in. x 17
in. (432 mm x 432 mm) opening required.
• Measure opening on the horizontal; actual length may
be larger depending on roof pitch.
• Cut out and frame opening.
Install Flashing
• Assemble chimney so it passes through the framed
opening.
• Slip the flashing over the chimney.
NOTICE: Roofing shingles must be below the flashing
plate on the lower side of a sloped roof and over the
flashing plate on the sides and top.
• Nail the flashing to the roof. Keep gaps between the
flashing plate and the roof to a minimum.
• Caulk the flashing plate and roof junction as well as
the vertical seam on the flashing. All nail heads must
be caulked with a roofing sealant.
• Caulk the overlap seam of any exposed pipe sections
that are located above the roof line to prevent leaks.
H. Install Chase/Chase Top
• You MUST use a chase top in a chase installation.
Chase tops may be field constructed.
• Include a turndown and drip edge to prevent water
from seeping into the chase.
• Include a 2 in. (51 mm) soldered, welded or spun
collar around pipe opening to keep water out.
• Provide a 1/8 in. (3 mm) gap around the flue pipe.
• Slope the chase top downward away from the
opening.
WARNING! Risk of Fire! DO NOT caulk the pipe to the
chase top collar.
• Caulk all seams to prevent leaks.
22 Majestic Ashland Series • ASH42 Installation Manual • 4059-915 • Rev M • 07/20
Figure 5.9 Ceiling/Attic Construction
Slope Downward
(1/4 in. per foot
minimum)
Figure 5.10 Chase Top Construction
2 in. (51 mm) Collar
on Chase Top
Turn-down
Drip Edge
Chase
.018 (26 ga) min.
Galvanized
Chase Top