Can I make the cut out for an attic fan from the attic then all I need to do from the roof is install the fan?

Question

That would mean less tools to haul up to the roof plus a little safer. I could use a reciprocating saw to make the cutout from underneath to cut the wood and use a utility knife to cut along the perimiter of the cutout to remove the sheathing and shingles. Why not?

Answer 1

That is how my installer did it.

Consider a solar operated fan.

Answer 2

If you use a re-ciprocating saw (sawzall), as you should, you will cut through the entire roof....Sure this is the way to go....flash well, and make sure the fan provides a good seal using ample tar,   especially the top side....of the fan.

Answer 3

thats the way i do it but cut the shingles along with it

Answer 4

Absolutely have to agree with REX on this one, NOT on the roof.

   Whether or not the attic is finished, install an exhaust fan at one end, in the perimeter wall, and at the opposite end you can install a register vent, allowing flow through air passage, or closed the opposing vent.

   Why disrupt the structure and integrity of a roof, when it isn't necessary?

Steven Wolf

Just my two "sense"

Answer 5

Absolutely, easier to get the hole centered where you need it, Allow 1" of clear space around any vent that will exhaust heat. Vent stack for plumbing can be tighter.

Also remember that  the hole will need to be slightly oval if it is at a steep angle.

Answer 6

We have an attic fan, but we stayed away from the roof.  You can push the air out of the attic on either end of the house. the Louvres  opens when the fan is in use.& they close when not in use..We can use it in any kind of weather..(no worry about snow on the roof)