Vaulted Ceiling Venting - Insulation - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Insulation

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Like Tree7Likes
Reply
 
Thread Tools Search this Thread
Display Modes
Old 01-29-2019, 09:27 AM   #1
Member
 
Join Date: Jun 2016
Posts: 312
Rewards Points: 618
Default

Vaulted ceiling venting


When insulating a vaulted ceiling, do you use rafter vents all the way from soffit to ridge in every bay? All my bays are vented.
Richard Pryor is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-29-2019, 09:36 AM   #2
retired painter
 
Join Date: Jun 2017
Location: east tenn
Posts: 9,729
Rewards Points: 288
Default

Re: Vaulted ceiling venting


The ventilation needs access all the way to the exit vent, the ridge if it's a ridge vent. A lot depends on the size of your rafters and how thick the insulation is but if the intake air can't make it to the exit vent then it doesn't do any good.
mark sr is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-29-2019, 09:40 AM   #3
Member
 
Join Date: Jun 2016
Posts: 312
Rewards Points: 618
Default

Re: Vaulted ceiling venting


Rafters are 2x12 and insulation will be r38. Yes I thought so. Thanks.
Richard Pryor is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-29-2019, 10:08 AM   #4
Member
 
Join Date: Nov 2015
Location: Maine
Posts: 10,762
Rewards Points: 326
Default

Re: Vaulted ceiling venting


Just to clarify, the rafter vents should only be above the insulation where they protect the bottom of the roof from contact with the insulation. vents should not extend above or below insulated areas. If vents were run from soffits to ridge there would be little temperature induced air flow. The warm air we want to exhaust out is actually the reason the ventilation works.

Bud
Richard Pryor likes this.
__________________
I volunteer my help and opinions, but you are responsible for what YOU choose to do with that information.
Bud9051 is online now   Reply With Quote
Old 01-31-2019, 11:03 PM   #5
Member
 
Join Date: Jun 2016
Posts: 312
Rewards Points: 618
Default

Re: Vaulted ceiling venting


Hi @Bud9051 . I don’t quite understand your answer. If I’m using r38 batts, they would be packed tight against the bottom of the roof correct? So I need vents from soffit to ridge or not? Like this?

Richard Pryor is offline   Reply With Quote
Old 01-31-2019, 11:21 PM   #6
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 38,184
Rewards Points: 976
Default

Re: Vaulted ceiling venting


Yes you need that on the slope and at the soffit but not in the space behind the nee wall.
Nealtw is online now   Reply With Quote
Old 01-31-2019, 11:24 PM   #7
Member
 
Join Date: Jun 2016
Posts: 312
Rewards Points: 618
Default

Re: Vaulted ceiling venting


I guess I chose a bad picture. This is a vaulted ceiling with rafters. No trusses so there’s really no knee wall. I need to use bats all the way from soffit to ridge.
Nealtw likes this.
Richard Pryor is offline   Reply With Quote
Old 01-31-2019, 11:30 PM   #8
Member
 
Join Date: Jun 2016
Posts: 312
Rewards Points: 618
Default

Re: Vaulted ceiling venting


This is a better picture. Is this the way to do it?

Richard Pryor is offline   Reply With Quote
Old 01-31-2019, 11:33 PM   #9
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 38,184
Rewards Points: 976
Default

Re: Vaulted ceiling venting


Yes, and you will be doing above the light too?
Nealtw is online now   Reply With Quote
Old 01-31-2019, 11:43 PM   #10
Member
 
Join Date: Jun 2016
Posts: 312
Rewards Points: 618
Default

Re: Vaulted ceiling venting


That was the plan @Nealtw unless you tell me otherwise. It’s just a picture I found on google.
Nealtw likes this.
Richard Pryor is offline   Reply With Quote
Old 02-01-2019, 12:18 AM   #11
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 38,184
Rewards Points: 976
Default

Re: Vaulted ceiling venting


Quote:
Originally Posted by Richard Pryor View Post
That was the plan @Nealtw unless you tell me otherwise. Itís just a picture I found on google.
That is about what you want.
Richard Pryor likes this.
Nealtw is online now   Reply With Quote
The Following User Says Thank You to Nealtw For This Useful Post:
Richard Pryor (02-01-2019)
Old 02-01-2019, 06:46 AM   #12
Member
 
Join Date: Nov 2015
Location: Maine
Posts: 10,762
Rewards Points: 326
Default

Re: Vaulted ceiling venting


Here's a good article on insulating a cathedral ceiling.

I realize those were just sample pictures but one concern I have with the narrow baffles is they only address the middle portion of the rafter cavity, especially if 24" on center and just one baffle is used.

Bottom to top is correct however, if you are adding recessed lights, especially if more than one per rafter bay, the amount of ventilation for those bays will be far short of what is needed. Example:
Guidance on ventilation for a regular attic is intended to remove excess heat from the entire attic so a few can lights share their heat across a large volume. But a cathedral ceiling limits the volume of air to just the gap above the insulation in one bay, each bay being separate. A better approach is full width baffles, often made on site, and a larger gap, 2" is recommended. But the limited space doesn't allow for added insulation above the lights so difficult to make it right. LED lights would help or surface mounted would be better.

Bud
Richard Pryor and Nealtw like this.
__________________
I volunteer my help and opinions, but you are responsible for what YOU choose to do with that information.
Bud9051 is online now   Reply With Quote
The Following User Says Thank You to Bud9051 For This Useful Post:
Richard Pryor (02-01-2019)
Old 02-01-2019, 09:16 AM   #13
Member
 
Join Date: Jun 2016
Posts: 312
Rewards Points: 618
Default

Re: Vaulted ceiling venting


Thanks for that article @Bud9051 . After reading it, I’m a little concerned about my situation. We have a valley on one side of the vaulted ceiling. The framer’s idea of venting is as follows.



I realize this is a recipe for disaster so I’m hoping you and @Nealtw can tell me what to do.

I would be inclined to do spray foam on that side of the ceiling only, but that corner will have a wood stove chimney coming out. And in my current shop we have spray foam and the amount of leakage due to condensation where the chimney exits the building is insane during winter. So I would rather avoid spray foam altogether.

Here’s a look at the house from outside.



PS every bay was vented prior to framing the valley. So there is venting there.

Last edited by Richard Pryor; 02-01-2019 at 09:18 AM.
Richard Pryor is offline   Reply With Quote
Old 02-01-2019, 09:29 AM   #14
Member
 
Join Date: Jun 2016
Posts: 312
Rewards Points: 618
Default

Re: Vaulted ceiling venting


Maybe I can do spray foam on every bay except the one where the stove pipe will be installed to avoid condensation problems? Here’s what my shop looks like. You can see drops of water if you look closely.

Richard Pryor is offline   Reply With Quote
Old 02-01-2019, 09:34 AM   #15
Member
 
Join Date: Nov 2015
Location: Maine
Posts: 10,762
Rewards Points: 326
Default

Re: Vaulted ceiling venting


I'm not totally understanding the intended air flow and valley situation, but do know that valleys create a block preventing low to high ventilation. for your next house the solution is to strap the top of the rafters before the sheathing goes on. That provides a gap so all rafter bays can communicate with all others and complete the air flow.

let's see what neal says.

Bud
__________________
I volunteer my help and opinions, but you are responsible for what YOU choose to do with that information.
Bud9051 is online now   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Insulation of Vaulted Ceiling Ferrino Insulation 2 05-08-2013 11:58 PM
Drywall over open beam ceiling and venting daluu Remodeling 4 11-07-2012 12:54 AM
Vaulted ceiling crown molding with adjacent room cmcfalls2 Carpentry 4 10-13-2011 10:38 AM
Crown moulding with a vaulted ceiling? cstrat Carpentry 34 06-17-2011 06:51 PM
Vaulted Ceiling Insulation Problem casey_wa Roofing/Siding 13 05-08-2006 09:55 AM




Top of Page | View New Posts