Double roof and vent for bath exhaust

digitalplumber · 02-14-2013, 08:12 PM

Need to install an exhaust vent on the roof for a bath exhaust fan. The only issue is that there is a wood shake roof with a regular three tab over it. Roof do for replacement in a year.

Anything special about how to make this install happen?

AndyWRS · 02-14-2013, 08:59 PM

If the comp is in really bad shape it will be a pita.

If the comp is ok, install the vent flashing as you normally would for a comp install, the only difference is your going to cut through the old shake roof in the process.

homeenergypros · 02-15-2013, 12:11 PM

If the roof is due to be changed in a year and the vent is close to a soffit or under eve could you just direct the heat out of the soffit vent? we do this a lot. just has to be pushed firmly into vent to and directed down. water and condensation should not be a problem if directed properly

digitalplumber · 02-15-2013, 01:38 PM

Quote:

Originally Posted by homeenergypros

If the roof is due to be changed in a year and the vent is close to a soffit or under eve could you just direct the heat out of the soffit vent? we do this a lot. just has to be pushed firmly into vent to and directed down. water and condensation should not be a problem if directed properly

Thanks, unfortunately this house does not have a traditional soffitt. Only has blocks of wood horizontally between rafters. I thought about just exiting there but these horizontal boards are at a slight angle, so the vent would always be open.

drtbk4ever · 02-15-2013, 03:25 PM

Quote:

Originally Posted by homeenergypros

If the roof is due to be changed in a year and the vent is close to a soffit or under eve could you just direct the heat out of the soffit vent? we do this a lot. just has to be pushed firmly into vent to and directed down. water and condensation should not be a problem if directed properly

If you go this route, use it only as a temporary fix until you can do it properly. Remember that soffit vents are designed to bring air into the attic which then exits at the ridge vent or roof vents. Adding a source of moisture to this airflow will, over time, lead to mold and rot issues.

digitalplumber · 02-15-2013, 03:48 PM

Quote:

Originally Posted by drtbk4ever

If you go this route, use it only as a temporary fix until you can do it properly. Remember that soffit vents are designed to bring air into the attic which then exits at the ridge vent or roof vents. Adding a source of moisture to this airflow will, over time, lead to mold and rot issues.

There are no soffit vents on this house like you are thinking of. Let me see if I have a picture I can post.

digitalplumber · 02-15-2013, 03:59 PM

Here is what the eaves look like

drtbk4ever · 02-15-2013, 04:00 PM

Sorry about that digital plumber, my comment was meant more for others who do have vented soffits.

02-14-2013, 08:12 PM	#1
digitalplumber Member Join Date: Jul 2011 Location: Houston Texas Posts: 476	Double roof and vent for bath exhaust Need to install an exhaust vent on the roof for a bath exhaust fan. The only issue is that there is a wood shake roof with a regular three tab over it. Roof do for replacement in a year. Anything special about how to make this install happen? __________________ digitalplumber is just a name for use here, I am not a plumber!

02-14-2013, 08:59 PM	#2
AndyWRS Metal Roofing Join Date: Jan 2012 Location: Mission Viejo, CA Posts: 280	Double roof and vent for bath exhaust If the comp is in really bad shape it will be a pita. If the comp is ok, install the vent flashing as you normally would for a comp install, the only difference is your going to cut through the old shake roof in the process.

02-15-2013, 12:11 PM	#3
homeenergypros Newbie Join Date: Feb 2013 Posts: 2	Double roof and vent for bath exhaust If the roof is due to be changed in a year and the vent is close to a soffit or under eve could you just direct the heat out of the soffit vent? we do this a lot. just has to be pushed firmly into vent to and directed down. water and condensation should not be a problem if directed properly

02-15-2013, 03:59 PM	#7
digitalplumber Member Join Date: Jul 2011 Location: Houston Texas Posts: 476	Double roof and vent for bath exhaust Here is what the eaves look like __________________ digitalplumber is just a name for use here, I am not a plumber!

02-15-2013, 04:00 PM	#8
drtbk4ever Newbie Bill Join Date: Dec 2008 Location: Alberta, Canada Posts: 1,032	Double roof and vent for bath exhaust Sorry about that digital plumber, my comment was meant more for others who do have vented soffits. __________________ Bill A DIY Noob that knows just enough to be dangerous.

Double roof and vent for bath exhaust