Instructions / Assembly

Installing Vents into Existing Finished Roofs
1. Inspect the attic to determine the location of the rafters and any other obstructions and
ensure that attic insulation is not blocking intake vents.
2. Determine how much additional ventilation is required and best location for the holes.
3. Mark the location of all roof vents before cutting holes. Center the holes between the
rafters down two feet (24″) from the peak of the roof.
4. Holes should be cut 11″ High x 10″ Wide. The Python™ 65 Slant Back Vent box has a
template for error proof installation. Using the template mark the outline for the hole
on the roof. The hole in the roof should never be larger than the hole at the bottom of
the vent.
5. Mark the holes in the appropriate locations on the top of the shingles.
6. Using a sharp knife and cut away the shingles.
7. Drill a pilot hole and cut through the sheathing using a keyhole saw or electric
reciprocating saw.
8. Inspect the hole for size and location and compensate if necessary. If the hole must be
modified, ensure that any change will not enlarge the hole beyond the maximum
recommended size. Add sealant around the edge of the hole.
9. Carefully remove the roofing nails within three inches of the hole.
10. Slide the vent into place beneath the shingles ensuring that the throat of the vent is
centered on the hole.
11. Secure the vent base with a minimum of 8 galvanized nails. Nails should be a minimum
of 1 1⁄4″ long and should penetrate the vent, shingle, and decking. Secure a nail in each
corner of the vent flashing and along the middle of each side of the vent.
12. For proper sealing use a plastic friendly roofing sealant. All nails to receive a dab of
sealant.
13. Shingle up and around the vent ensuring that the shingles butt up against the throat of
the vent.
14. Replace nails in the shingles as necessary to ensure a proper seal.
Note: The Python™ 65 Slant Back Vent does not provide warranty for leaks from water
penetrating under shingles or roofing underlayment.