Bathroom Vent Through Roof

Run a thick bead of tri polymer sealant along the underside of vent hood.

Bathroom vent through roof. Take the end of the duct with the connector fitting and attach it to bath vent fan. Some veteran builders used to consider a soffit as an appropriate placement for the event outlet but section m1501 1 of the 2012 international residential code irc changed the language to disallow exhausting through a soffit vent or ridge vent or into an attic or crawl space leaving a side wall or roof as the only two options. This involves running ductwork from the fan usually though an attic and out through the roof.

The 2018 irc contains the same language. The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. The bathroom exhaust should never be vented anywhere near nor through the soffit area.

Cooler air which is found under your roof overhang soffit is drawn up through the perforations of the soffit and exhausted through your roof venting system. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. The 2 pipes one a 4 master and the other a 3 2nd do not go through the ceiling but into a common box that goes through the roof.

Bath exhaust fans routed up through the roof. Pass the opposite end of the duct through the hole in roof. Next use aviation snips to cut slits into the sheet metal sleeve.

Bend over the tabs then nail the tabs to the roof. Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot. The master bathroom and the 2nd bathroom vent through the roof and through the same opening.

It is because of this that many builders tend to advise against this method. I prefer to run a bath vent to outdoors via a horizontal line that goes across an attic and out through a gable end wall or one that vents down and outside through a roof overhang or soffit. Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out.