Ventilation Louvres

I want to vent my bathroom fan out the gable wall of my attic. Its concrete block wall. How do I do this?

Can I just drill the 4" hole through the concrete block? There are no studs to go between as usually recommended. For the strength and integrity of the wall, can I just go right through any block? I guess I should drill from the inside, in order to center the hole in the middle of the block, correct? Not an apartment or condo. Just a regular old concrete block house with vinyl siding.

Public Comments

1. Drill a pilot hole then with the hole saw drill half way from each side.
2. drill straight out from in and catch any block
3. im guessing you are in a condo/townhouse??if so,its illegal to penetrate the firewall between two units,for the obvious reason.They are concrete or double layers of fire resistant drywall to keep fire from spreading between units.If you get caught,you are in for one LARGE fine,not to mention your insurance co will declare you uninsurable. ok,then the easiest way to get through the wall is using a cold chisel and a hammer,tapping away on the block until you get through one side.keep in mind that concrete blocks have webs in them,so you want to stay 2" in from either end and start your hole,or 6" from either end to the center of the hole.youlll probably have to point up after the vent pipe is through,just take some mixed mortar and patch around the pipe,sealing the hole on both sides.
4. Rebar could be a problem if it is drill a pilot hole through the block,drill the 4'' hole through one side,If no rebar go through the brick,!/2 on one side 1/2 on the other side depending on the drill your using.If there is rebar drill from both sides untell you get to the rebar and then somehow cut it out,,Make sure there is a pilot hole so the cut from the other side if you do it that way is centered. Hope this helped....
5. I'd recommend drilling a pilot hole through the wall first (1/4" diameter). Then use a diamond bit hole saw (whatever diameter is needed) and drill 1/2 halfway from both sides. This will prevent the block from flaking or busting out, especially on the finished side. It also prevents the heavy piece from possibly falling and damaging something. Drill bits will cut through masonry and steel, so there shouldn't be a problem if there isn't any electrical wires or plumbing pipes in that particular location.
6. check your location outside first then mark it inside if all is good if its block find the mortar lines around one block drill several holes with masonry bits (using a hammer drill would be best) then with several holes along the mortar lines chip away at the mortar until block comes away and if one block isnt enough for hole then do next one until hole is big enough for exhaust then you can refill hole around exhaust duct with new cement and if needed bits of an old block depending on size of gap needed to filled. note when knocking out brick make sure someone is outside watching and keeps people clear for you. you can also use masonry blades with a crinder or even a circular saw to sut mortar lines around brick.good luck
7. go to lowes home depot etc and buy a concrete masonry core bit for your dril. and core between the webs. the webs are bloc are the ends and middle typically i" thick. Make sure your drill can handle the load or you will be replacing it as well. I used to core drill for a living and use both a stahl/ dewalt hammer drill or a commercial core machine they both do the trick.