Broan 345SOBK Instructions Manual page 3

6. From the roof side, using the guide hole as the center
point, use a nail and string to scribe a 16-1/2" diameter
circle on the shingles. Note: If replacing an existing
ventilator, the hole diameter may be larger than 16-1/2" .
This is acceptable provided the roofing material overlaps
the ventilator by at least 2" on all sides.
7. Cut out the shingles inside of the circle.
8. Using the same nail and string shown in step 6, scribe
a 14" diameter circle on the black paper or roof decking.
Note: if replacing an existing ventilator the hole diameter
may be larger than 14" . This is acceptable provided the
ventilator base is adequately supported by the roof
decking.
MODELS 345SOBK • 345SOWW
9. Drill a large starting hole for the sabre saw just inside of
the line or the 14" circle created in Step 8.
10. Cut out the roof board(s) inside of the line.
11. For proper removal of roofing nails, draw a 27" square,
centered around the hole. Remove nails holding shingles
down from top two-thirds of square.
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