On Aug 22, 3:40*pm, Joe wrote:
On Aug 22, 9:08*am, RicodJour wrote:

snip
Locate the studs, plumbing (don't forget vents!) and electrical lines
first, pick the more critical side and use a 12" bit to drill through
the wall, then use your hole saw or recip to cut the holes from both
sides.

Good advice.
Also remember it is a good practice to have a slight downward slope to
the outside for horizontal runs of venting. Tends to keep casual
condensation or other moisture outdoors where it belongs, so they say.

Joe

Agree; downward. Never problem with our clothes dryer outlet, but our
bathroom exhaust fan pipe sloped 'up' (somebody, maybe from a warm
climate, recommended that way) so we had condensation in the pipe due
to cold air in the attic and some slight amount of condensation did
leak back and dripped onto one ceiling. The stain is still there!
BTW. Insurance requirement here, now, is that the dryer hose not be
plastic. So we replaced ours with flex aluminum. Connected to metal
through to outside wall fitting.