DuraVent Ventinox Rigid Factory-Built Lining System - Manual (Page 8)

General Guidelines:
Duravent Liners have been tested and are listed to
UL 1777 and ULC-S635 standard at zero clearance to
combustibles and for use with all fuels. When venting
wood fired heaters or fireplaces, a minimum of one inch
TherMix ® or at least 1/2" of ProFoil are needed to conform
to the UL1777 and ULC-S635, zero clearance listing.
All temperature tests were performed on chimneys
featuring a 4” nominal masonry shell and a Security Liner
with or without the specified insulation between the liner
and interior of the chimney (no clay tiles). The outside of
the chimney was surrounded with a wood enclosure at
zero clearance as specified by the standard.
METHOD #1: INSULATING WITH
THERMIX
®
TherMix ® is poured into the chimney AFTER the liner is
installed. TherMix ® is a pre-mixed insulation material and
only requires the addition of water at the job site. Review
TherMix ® literature to determine the volume of TherMix ®
needed to fill a specific chimney.
Empty a TherMix ® bag into a mortar trough or
wheelbarrow. Add 7 to 9 gallons of water and mix with a
hoe. Proper consistency is achieved when the material
feels damp but is still granular. Little or no water should
appear between fingers when a handful of TherMix ® is
squeezed. Correctly prepared TherMix ® pours like “loose
fill” into the void between the liner and the chimney.
Complete instructions are on each TherMix ® bag.
During the pouring process, distribute the insulation
evenly into the available space. Spacers may be used
every 5 ft. to center the liner. Vibrate the liner by firmly
tapping it. Continue to pour TherMix ® until the chimney is
filled to the top and finish as described previously. Inspect
the liner at this time to ensure that no TherMix ® has fallen
inside the venting system.
All heaters or fireplaces can be fired up right after the
installation is complete. Keep flue gas temperatures below
700 degrees F for three weeks. This allows for TherMix ® to
dry gradually. The operator is responsible for making sure
that the heater is not over fired during this initial period.
METHOD #2: INSULATING WITH
PROFOIL OR FLEXWRAP CERAMIC
BLANKETS.
Ceramic blankets are attached to DuraVent Liners as
the liner is installed into the chimney. Blankets are 1/2" in.
thick, 8 pounds density, and faced with a 2 mil. aluminum
Bag of TherMix
VENTINOX LINING SYSTEM - 8
INSULATING DURAVENT LINERS
foil. The 1/2" thick blanket is the minimum amount of
insulation needed when using ProFoil. If using 1/4" ProFoil
blankets, two wraps are necessary to achieve the required
1/2" insulation. Aluminum tape, wire mesh and clamps are
needed for proper installation.