19
February 19, 2020
7037-801B
Floor
Protector
Chimney
Connector
Ceiling Support
Listed Chimney
Listed Termination Cap
Storm Collar
Flashing
Figure 19.1 - Prefabricated Interior Chimney
Thimble
Site constructed for masonry chimney installation:
Components
A minimum length of 12 inches [305mm] (longer for thicker
walls) of solid insulated factory-built chimney length
constructed to
UL 103 Type HT
6 inch (152mm) inside
diameter. Chimney needs to extend a minimum of 2 inches
(51mm) from the interior wall and a minimum of 1 inch
(25mm) from the exterior wall.
Wall spacer, trim collar and wall band to fit solid pack
chimney selected.
Minimum 8 inch (203mm) diameter clay liner section (if not
already present in chimney) and refractory mortar.
When jurisdiction requires install approved chimney liner in
masonry chimney.
Air Clearances
• Masonry chimney clearance must meet
NFPA 211
minimum requirement of 2 inches (51mm) to sheet
metal supports and combustibles.
•
Minimum of 1 inch (25mm) clearance around the
chimney connector.
• Top of wall opening is a minimum of 13-1/2 inches
(343mm) from ceiling or 4-1/2 inches (114mm) below
minimum clearance specified by chimney connector
manufacturer.
NFPA 211
minimum vertical clearance of
18 inches (457mm) from chimney connector and ceiling
or minimum recommended by chimney connector
manufacturer
(Figure 19.2)
.
Instructions:
1. Open inside wall at proper height for the chimney
connector to entry the masonry chimney
(Figure 19.2)
.
2.
Entry hole to masonry chimney must be lined with
an 8 inch (203mm) minimum diameter clay liner, or
equivalent, secured with refractory mortar.
3.
Construct a 17 inch x 17 inch (432mm x 432mm)
outside dimension frame from 2 x 2 framing lumber to
fit into wall opening. Inside opening of frame should
be no less than 14 inch x 14 inch (356mm x 356mm)
(Figure 19.2)
.
4. Attach the wall spacer to the chimney side of the frame.
5. Nail the frame into the wall opening. The spacer should
be on the chimney side.
6. Insert the section of the solid insulated chimney into the
outer wall of the masonry chimney.
7. Tightly secure the length of the solid insulated chimney
with the wall band to the masonry chimney.
8. Insert a section of chimney connector into the chimney.
Make sure it does not protrude past the edge of the
clay chimney liner inside the chimney.
9. Seal the end of the chimney connector to the clay liner
with refractory mortar.
10. Install trim collar around the solid pack
chimney section.
Figure 19.2
1.5”
1.0”
2.0”
2.0”
1.5”
14.0” ID
17.0” OD
ceiling
13.5” below ceiling to top of
opening or top of opening is a
minimum of 4.5” below
minimum clearance specified
by connector manufacturer.
1.0”
8.0”
1.5 2x2 framing stud
2.0 min air clearance
1.0 min air clearance
4.5
Center of Hole
Minimum 18.0”
NFPA 211
Thimble
Wall
Include depth
of hearth pad
