Chapter
3
Installation
America’s
Favorite
Stoves
Since
1980
Page
19
B
LOCK
‐
O
FF
P
LATE
I
NSTALLATION
Whenever
this
appliance
is
installed
with
a
direct
connection
a
block
‐
off
plate,
or
other
noncombustible
seal
‐
off
device
(e.g.
damper
adapter),
will
need
to
be
installed.
This
device
is
used
to
seal
the
chimney,
insuring
no
smoke
enters
the
home
and
providing
the
chimney
system
with
a
seal
to
promote
draft.
The
directions
below
detail
the
steps
for
construction
and
installation
of
a
block
‐
off
plate.
1.
Determine
a
location
for
the
block
‐
off
plate
at
the
top
of
the
firebox
below
the
damper
area
(make
it
high
enough
to
allow
installation
of
the
connection
pipe).
The
location
should
be
level
and
in
an
area
where
it
can
be
mounted
easily.
Measure
the
width
at
the
rear
("A")
and
front
("B")
of
the
firebox
at
the
height
where
the
block
‐
off
plate
will
be
installed
(see
the
illustration
below).
Then
measure
the
depth
of
the
location
where
the
block
‐
off
plate
will
be
installed
("C").
NOTE
:
Most
masonry
fireplaces
have
square
fireboxes
while
certain
zero
‐
clearance
(metal)
fireplaces
often
have
domed
firebox
tops.
This
makes
zero
‐
clearance
block
‐
off
plates
more
difficult
to
install.
To
simplify
the
procedure,
insulation
may
be
used
to
seal
the
rounded
edges.
2.
Make
a
cardboard
template
of
the
measurements,
but
add
a
2"
flange
to
each
side.
This
flange
will
be
used
to
mount
the
block
‐
off
plate
to
the
inside
of
the
firebox.
Bend
the
flanges
downwards
on
the
template
and
place
it
inside
the
fireplace.
If
the
template
fits
correctly
in
its
planned
location,
go
to
the
next
step.
If
it
does
not,
make
a
new
template
with
the
appropriate
corrections
until
it
fits
correctly.
3.
With
the
template
in
place,
mark
the
location
of
the
flue
(see
“Dimensions”
on
page
6).
This
location
approximates
the
center
of
the
flue
when
the
insert
is
in
place
(a
slight
offset
may
occur
based
upon
insert
and
block
‐
off
plate
placement).
Remove
the
template
and
cut
a
6
1/4"
diameter
hole
centered
on
this
mark.
4.
Make
the
block
‐
off
plate
of
24
gage
or
thicker
steel
to
match
the
template.
Drill
two
holes
in
each
flange
for
mounting
the
plate.
5.
Mount
the
block
‐
off
plate
using
masonry
screws.
NOTE
:
Use
sheet
metal
screws
on
zero
‐
clearance
(metal)
fireplaces
(screws
need
only
be
long
enough
to
penetrate
the
first
layer
of
metal).
6.
Insulate
the
block
‐
off
plate
using
high
‐
temperature
fiberglass
insulation
(Ceri
‐
blanket®
or
equivalent)
and
furnace
cement
(allow
the
cement
to
dry
for
at
least
24
hours
before
burning).
7.
After
placing
the
appliance
and
installing
the
pipe
through
the
block
‐
off
plate,
use
high
temperature
fiberglass
insulation
and
furnace
cement
to
seal
any
cracks
between
the
pipe
and
block
‐
off
plate.
