Recessed lights generate lots of heat.
In fact, some operate at temperatures
up to 200°F. In the uninsulated attics
of many old houses, these fixtures may
work for years without incident.
Problems start when a contractor
insulates the attic, usually as part of a
larger renovation. If you pile insulation
on top of a recessed fixture,
there's no way for the heat to dissipate.
As a result, the framing and
other combustibles around the fixture
can get hot enough to catch fire.
That's why building codes require
attic insulation to be held back from
recessed lights. Most codes follow the
"3 to 4 rule" — they specify a clearance
of between 3 and 4 inches (check