MHSC BR36 Installation And Operating Manual page 10

BR/BC Series Woodburning Fireplaces
Straight-Up Chimney Installation
To mark the centerline of the flue, put the fireplace
in final position and measure out from the wall: 8Z⁄v"
(210 mm)
Mark a spot on the ceiling directly above the fireplace.
Draw a line parallel to the back wall through this mark.
(Fig. 11)
Using a plumb bob positioned directly over center point
of fireplace flue collar, mark the ceiling to establish the
chimney center point. (Fig. 11)
Chimney Centerline
Actual Centerpoint
Fig. 11 Locate centerline of chimney with plumb line.
Offset Installation
In order to clear an obstruction, it may be necessary to
offset chimney from vertical. This is accomplished by
using MHSC elbows. Use the 30° Offset Elbow table on
Page 6 to determine proper offset and parts required.
Each offset requires two (2) elbows. The second elbow
is equipped with support straps. It is very important to
install the second elbow in each offset as close to the
ceiling or support as possible so that the elbow straps
can be secured to framing members to help support the
weight of the chimney.
10
"
(210mm)
Plumb Line
Plumb Bob
Imaginary
Centerpoint
FP556
FP556
BR/BC
LOCATE CENTER LINE
11/10/97
Determine offset distance of your chimney arrangement
from centerline of fireplace to centerline of chimney
where it is to pass through ceiling.
Locate center point of the chimney on ceiling as though
a straight up chimney arrangement is to be used. Mea-
sure your offset dimension from straight up chimney
center point on ceiling.
Ceiling Chimney Hole/
Possible Obstructions
The size of the hole in ceiling will vary with the angle at
which the chimney passes through ceiling.
Drive a nail up through ceiling at marked chimney
center point. Go to floor above and see where hole
will be cut. Check to see where existing ceiling joists
and other possible obstructions are located...i.e. wiring,
plumbing etc... If necessary, re-position chimney and/or
fireplace to avoid obstructions.
Cutting the Hole
Cover fireplace collar opening and cut proper sized
chimney hole in chimney. The SK8 pipe allows you to
run pipe through a typical 16" on center joist without
cutting joists.
Framing the Ceiling Hole
Frame the ceiling chimney hole as shown in Figure
12. It is good practice to use framing lumber that is the
same size as the ceiling joists; this is a requirement at
attic level.
AB
Existing Ceiling
Joists
Ceiling
New Framing
Members
A "SK" Series framing = 14Z⁄₂" X 14Z⁄₂" (368 x 368mm)
B "S" Series framing = 17Z⁄₂" X 17Z⁄₂" (445 x 445mm)
Fig. 12 Typical frame for ceiling chimney hole.
AB
Chimney
Hole
FP551
FP551
BR/BC
9/29/97
7412944