Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Roofing/Siding

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

Reply
 
Thread Tools Search this Thread Display Modes
Old 06-19-2010, 04:44 PM   #1
Member
 
Join Date: Jun 2010
Posts: 42
Rewards Points: 25
Default

Ridge Vent Size


Is thee a recommedned minimum length for a ridge vent to be effective?

Alto is offline   Reply With Quote
Old 06-19-2010, 05:33 PM   #2
Shut in w/o Home
 
seeyou's Avatar
 
Join Date: Dec 2008
Location: Lexington, KY
Posts: 696
Rewards Points: 500
Default

Ridge Vent Size


If your vents are split between ridge vents and intake vents, the minimum requirement is 1 square foot of ventilation or net free area for every 300 square feet of attic floor space.

seeyou is offline   Reply With Quote
Old 06-29-2010, 12:27 PM   #3
Member
 
Join Date: Jun 2010
Posts: 42
Rewards Points: 25
Default

Ridge Vent Size


I am back to working on my roof and the question of rdige vents has come up again. Seems to me like one of the most important things is venting. Sorry to say but i am so new at this i don't understand your answer here. Do you mean that a ridge vent 20 feet long by as many inches in width that the opening of the riodge vent is --the square footage of the opening of the vent; let's say 20 feet X 8 inches- should be a functioin of every 300 square feet of attic space?

Right now I have two or three pretty small -- probably less than a foot across -- passive round vents coverend with a metal "bublble" . Good soffit boxes all around the house. I have been told not to keep these passive vents with a ridge vent. I also understand that these alone would not necessarily work today because the roofing material is not as good today as it was 40 years ago when they put on my present roof.

Wouldn't the surest thing to do be to close off the passive vents and put in two electric ones?
Alto is offline   Reply With Quote
Old 06-29-2010, 01:03 PM   #4
Shut in w/o Home
 
seeyou's Avatar
 
Join Date: Dec 2008
Location: Lexington, KY
Posts: 696
Rewards Points: 500
Default

Ridge Vent Size


Each brand/model of ridge or any other type of vent has a specific sq in/sq ft free air rating. So if you have a 300 sq ft attic, you need 1 sq ft (144 sq in) of inlet/outlet combined. So you'd need 72 sq in of inlet and 72 sq in of outlet. If you use a ridge vent that gives 9 sq in of free air per foot, you'd need 8 lin ft of ridge vent. These are minimum requirements.

If you're venting to reduce the temperature in your living space, you'd be better off increasing the insulation. Vent to remove moisture from the attic.
seeyou is offline   Reply With Quote
Old 06-29-2010, 02:17 PM   #5
Member
 
Join Date: Jun 2010
Posts: 42
Rewards Points: 25
Default

Ridge Vent Size


I am going to have to do the measurements. I have received an interactive table from Owens cornings that gives measurements. But it seems like I am going to need a whole lot more venting than I have space for. What do you do in this situation? is this when you go to the elctric vents and how do you figure square footage per one of them?
Alto is offline   Reply With Quote
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
Ridge Vent: width of cut judym Roofing/Siding 12 09-09-2012 02:20 AM
Standing Seam Ridge Vent A.Pierce Roofing/Siding 8 08-04-2010 03:29 PM
Need Help with Ridge Vent on Unusual Roof MSBOY Roofing/Siding 1 03-24-2010 09:46 PM
ridge vent w/ roof louvres? byocum Roofing/Siding 3 08-31-2009 06:17 PM
Foundation crawl space vent size problem Constant Improvement Building & Construction 15 01-15-2009 05:07 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.