Forums | Home Repair | Home Improvement | Painting | Interior Decorating | Remodeling | Landscaping


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 07-24-2011, 03:22 AM   #1
Newbie
 
Join Date: Jul 2011
Posts: 4
Share |
Default

Venting a Roof


Question on roof venting

Currently have a 1400 square foot house (1901) with gable vents and a functioning cupola. No soffit vents and no way of putting them in without lowering the ceilings in the entire house. We are replacing the shake roof with architechtural shingles next week and I am needing help with the following questions:

1. Will the gable vents be the intake when there is a functioning cupola (apx. 4 feet by 4 feet) to serve as the exhaust?

2. Should I close the cupola and gable vents and put in a ridge vent and roof vent (right above the eave)?

3. Should I forget about venting all together and install spray foam insulation on the roof deck and go with the unvented attic/conditioned attic?

The roof is very complicated design - has 7 gables total so there isn't a lot of room to put intake roof vents - if we installed a ridge vent on the entire house it would not be a 50/50 mix by any means.

Thanks in advance for your help. I really appreciate any help you can offer.



KJ; Portland, OR
johnskat is offline   Reply With Quote
Old 07-24-2011, 08:25 AM   #2
Member
 
Join Date: May 2011
Location: OK
Posts: 218
Default

Venting a Roof


You might look at this;

http://www.airvent.com/professional/...-theedge.shtml

http://www.dciproducts.com/html/smartvent.htm#
josall is offline   Reply With Quote
Old 07-24-2011, 10:40 AM   #3
Newbie
 
Join Date: Jul 2011
Posts: 4
Default

Venting a Roof


These are the products I was looking at for a ridge/lower roof vent. But I am wondering if this is my best choice? Purchasing these items will cost over $1,000 and will leave me with too much exhaust vents and not enough intake because of a very weird and complicated roof design.
Thanks for any help you can offer
johnskat is offline   Reply With Quote
Old 07-24-2011, 03:52 PM   #4
Registered User
 
Join Date: Mar 2009
Posts: 9,886
Default

Venting a Roof


Built in 1901....... have you done any recent remodeling on it to warrant the additional venting? Is there a ventilation problem? Ice dams? Frosting/rusting nail points? Many houses along this Coast are fine with our moderate weather: http://www.fpl.fs.fed.us/documnts/pdf1999/tenwo99a.pdf

http://www.jlconline.com/cgi-local/v...170a32100a05c7

Gary
__________________
Clothes taking longer to dry?
Clean the dryer screen in HOT water if using fabric softener sheets.
They leave a residue that impedes air-flow, costing you money.
Clean the ducting in the last six months? 17,000 dryer fires annually!
Gary in WA is offline   Reply With Quote
Old 07-24-2011, 04:49 PM   #5
Newbie
 
Join Date: Jul 2011
Posts: 4
Default

Venting a Roof


We don't have any current problems with venting. We are concerned because we are removing the somewhat breathable shake roof and installing half inch plywood and asphalt shingles. Do you think that the gable vents and cupola are sufficient?
johnskat is offline   Reply With Quote
Old 07-25-2011, 11:00 PM   #6
Registered User
 
Join Date: Mar 2009
Posts: 9,886
Default

Venting a Roof


Check with your local B.D. for minimum venting requirements.

Gary
__________________
Clothes taking longer to dry?
Clean the dryer screen in HOT water if using fabric softener sheets.
They leave a residue that impedes air-flow, costing you money.
Clean the ducting in the last six months? 17,000 dryer fires annually!
Gary in WA is offline   Reply With Quote
Old 07-26-2011, 06:15 AM   #7
Member
 
Join Date: May 2011
Location: OK
Posts: 218
Default

Venting a Roof


I did the exact same thing a couple years ago and your attic will be hotter. The FHA recommends a minimum of at least 1 square foot of attic ventilation (both intake and exhaust) for every 300 square feet of attic space, I tthink you wiill be better served witth something closer to 1 sq.ft. of vent for every 150 sq.ft.. of attiic space. It sounds to me like you need to get intake at the soffit level. For venting to work, cool air must come in the bottom, it heats up on its way up the roof and exists out the top. You can't suck air out the top if cooler air doesn't come in somewhere else. 1400 sq.ft. is 9.33 sqft of vent, so about 4.5 exhaust and 4.5 intake. If you use the air vent you would need 18 4' pcs. at $15 is $270.. each pc provides 36 NFA. If you cant get 18 on, anythhing you do is better.
josall is offline   Reply With Quote
Old 07-26-2011, 11:23 PM   #8
Member
 
Join Date: Jan 2007
Posts: 2,384
Default

Venting a Roof


Quote:
Originally Posted by josall View Post
I did the exact same thing a couple years ago and your attic will be hotter. The FHA recommends a minimum of at least 1 square foot of attic ventilation (both intake and exhaust) for every 300 square feet of attic space, I tthink you wiill be better served witth something closer to 1 sq.ft. of vent for every 150 sq.ft.. of attiic space. It sounds to me like you need to get intake at the soffit level. For venting to work, cool air must come in the bottom, it heats up on its way up the roof and exists out the top. You can't suck air out the top if cooler air doesn't come in somewhere else. 1400 sq.ft. is 9.33 sqft of vent, so about 4.5 exhaust and 4.5 intake. If you use the air vent you would need 18 4' pcs. at $15 is $270.. each pc provides 36 NFA. If you cant get 18 on, anythhing you do is better.
Correction on your math.

Each lineal foot of the Shingle Vent II Ridge Vent provided 18 square inches of NFVA PER FOOT. So, each 4 foot section would provide 72 square inches of NFVA.

Otherwise, your recommendations for using the Smart Vent and the Shingle Vent II are right in alignment with my own preferences.

Ed
Ed the Roofer is offline   Reply With Quote
Old 07-26-2011, 11:24 PM   #9
Member
 
Join Date: Jan 2007
Posts: 2,384
Default

Venting a Roof


I agree and enthusiastically endorse both of these products based on past job experiences going back many years with both product manufacturers.

Ed
Ed the Roofer is offline   Reply With Quote
Old 07-27-2011, 06:56 AM   #10
Member
 
Join Date: May 2011
Location: OK
Posts: 218
Default

Venting a Roof


Ed, this was for edge vent not ridge vent.
josall is offline   Reply With Quote
Old 07-27-2011, 09:43 PM   #11
Member
 
Join Date: Jan 2007
Posts: 2,384
Default

Venting a Roof


Quote:
Originally Posted by josall View Post
Ed, this was for edge vent not ridge vent.
Okay.

But, irregardless of my misquoting your combined links attempts, the Ridge Vent from www.AirVent.com called Shingle Vent II would still be a good recommendation.

Ed
Ed the Roofer is offline   Reply With Quote
Reply

Tags
cupola, gable, venting


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
venting my roof properly MLMIB Roofing/Siding 2 08-12-2010 07:14 AM
Roof Venting??? JoAnn Roofing/Siding 2 03-17-2010 09:42 AM
Proper venting of new roof on attached garage jlatulippe Roofing/Siding 1 11-26-2009 03:24 PM
The moving Ice Dams after using a roof rake ?? Canufixit Roofing/Siding 9 02-05-2009 07:33 PM
Roof Venting Issue, crawlspace supton Roofing/Siding 1 11-12-2008 06:44 AM




Top of Page | View New Posts

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