How to install a dryer vent

What’s the best way to put a dryer vent through the exterior brick wall of my house? I don’t know how to cut a big, round hole through this material. - Ravi Shah, Thornhill, Ont.

There are a couple of things to think about, beyond the obvious challenge of how to get through that brick. One of the main issues involves installing a vent pipe in a way that’s easily removable later, for replacement, while also keeping out rain and preventing air leaks and condensation within the wall cavity during winter.

The trick is to install not just one pipe but two. Typical dryer vents are 4" in diameter, but instead of putting this pipe through the wall on its own, I recommend starting with a larger 5"-diameter galvanized steel pipe. Seal this pipe where it meets both the interior and exterior wall surfaces, then install the dryer vent through it.

Start work by determining the location of the wall studs in the area where you want the vent to be. Naturally, you’ll need to choose a spot where no stud exists and where wires are unlikely to be found. The zone within 8" of the floor is usually free of wires; however, you’ll want to cut a careful explora-tory inspection hole through the drywall  to get a peek into the wall cavity, just to make sure.

If all looks good, rent or borrow a rotary hammer spinning a 1⁄2" drill bit. This powerful electrical tool combines rotation and percussion to drill quickly through masonry. Bore a hole in the centre of the spot where you want your vent pipe to be, beginning inside the house and boring outward through the brick. (This same technique applies to houses with vinyl or aluminum siding, although you don’t need a rotary hammer. A regular drill with a long spade bit works fine.)