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 06-26-2012, 10:34 AM   #16
Member
 
Join Date: Mar 2012
Location: Massachusetts
Posts: 45
Share |
Default

Ranch Style Home Attic Ventilation


Good points made by all....

There is loose insulation the depth being just over the top of the 2x6 joists. So maybe 6 or 7 inches of loose insulation is there. Because of the shallowness of the roof the original builder didn't bother putting any flooring in the attic. So I ripped a couple of 4x8 sheets of plywood to put up there for flooring so I can walk around. Do you suggest adding several more inches of loose insulation? I certainly can do that. Maybe add the insulation and install some louvers and call it good??
ulrichfolkers is offline   Reply With Quote
Old 06-26-2012, 10:48 AM   #17
Member
 
Join Date: Jun 2012
Location: Phoenix AZ
Posts: 452
Default

Ranch Style Home Attic Ventilation


With 6'' of insulation I believe is R-19. Most home built nowadays depending on your area need at least R-38. Pump it in !
CopperClad is offline   Reply With Quote
Old 06-26-2012, 10:51 AM   #18
Residential Designer
 
AndyGump's Avatar
 
Join Date: Sep 2010
Location: Orange County CA.
Posts: 1,235
Send a message via Skype™ to AndyGump
Default

Ranch Style Home Attic Ventilation


Pump it in or use batts, just make sure you leave space for venting.

Andy.
__________________
Residential Drafter/Designer

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
AndyGump is offline   Reply With Quote
Old 06-26-2012, 10:57 AM   #19
Member
 
Join Date: Mar 2012
Location: Massachusetts
Posts: 45
Default

Ranch Style Home Attic Ventilation


Sounds like I have an agenda.....

Thanks much...
ulrichfolkers is offline   Reply With Quote
Old 06-27-2012, 08:29 AM   #20
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: VA, MD, DC
Posts: 5,065
Default

Ranch Style Home Attic Ventilation


Quote:
Originally Posted by CopperClad View Post
I'm going to have to disagree. I'm not a designer or anything.. but.. In the old days there was no such thing as ridge vent. Roofs would last 15 years if your lucky.. Ridge "vent" is to let the "hot" air vent. Heat rises to my knowledge. If it doesn't have anywhere to go? Attic gets hot, which in turn does wear on your shingles?? Look at the pics, your due for a reroof shortly, and with older shingles in itself is having a small effect. They even have energy star rated shingles now! Just my opinion though, let your roof breath. But yes, added insulation for sure sounds like a good idea as well. Good luck!
Shingle heat being touted as a destructive force is overused and largely promoted by the shingle manufacturers.

The difference in shingle surface temperatures between a sealed and completely vented attic are extremely slight (usually less than 2 degrees and this is in FL and Vegas). The differences will be even less in Northern climates or areas with shading.

+95% of the cooling happens via convection to outside and not through the plywood and into the attic.

Venting issues create moisture issues and those moisture issues can ruin a shingle...not the heat.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Windows on Wash is offline   Reply With Quote
The Following 3 Users Say Thank You to Windows on Wash For This Useful Post:
AGWhitehouse (06-29-2012), AndyGump (06-27-2012), CopperClad (06-27-2012)
Old 06-27-2012, 09:27 AM   #21
Member
 
Join Date: Jun 2012
Location: Phoenix AZ
Posts: 452
Default

Ranch Style Home Attic Ventilation


If the homeowner had a gable roof the venting wouldn't be issue. However the OP has a hip roof. When you say a 60/40 split, I think what you are saying is 60 intake, 40 exhaust ? In the OP's case, lets just say his home is a 50'x50' box. That means he has 200' of intake, and 8' of exhaust ... Just doesn't seem right at all to me. Again, that is just my opinion. If it were my home, I would be sure to add more outlet venting.

Last edited by CopperClad; 06-27-2012 at 10:33 AM.
CopperClad is offline   Reply With Quote
Old 06-27-2012, 10:20 AM   #22
Member
 
Join Date: Mar 2012
Location: Massachusetts
Posts: 45
Default

Ranch Style Home Attic Ventilation


Copperclad
I agree with you, and agree about adding more insulation. So, to reiterate, I'm going to add additional attic insulation and add louver vents.

Windows on Wash
Thanks for your input regarding moisture and heat issues with respect to roof shingles.

And Thanks again to all....
ulrichfolkers is offline   Reply With Quote
Old 06-27-2012, 02:09 PM   #23
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: VA, MD, DC
Posts: 5,065
Default

Ranch Style Home Attic Ventilation


Quote:
Originally Posted by CopperClad View Post
If the homeowner had a gable roof the venting wouldn't be issue. However the OP has a hip roof. When you say a 60/40 split, I think what you are saying is 60 intake, 40 exhaust ? In the OP's case, lets just say his home is a 50'x50' box. That means he has 200' of intake, and 8' of exhaust ... Just doesn't seem right at all to me. Again, that is just my opinion. If it were my home, I would be sure to add more outlet venting.
60/40 as a ratio is a good target number. Most roofs (especially today) will be heavy on the exhaust and lack on the intake. This is as a result of short cuts on the soffits, obstructed soffits or complex roof lines and poor intake.

Too much exhaust and not enough intake drives stack pressures and drive air exfiltration and moisture migration to the attic (exactly what we don't want to happen).

In the original posters question, he does need more exhaust to balance out the system without question. That needs to be addressed for certain.

Insulation is part of the equation. Air sealing is the other part of it.

Stop the air movement and you really put the brakes on the moisture movement.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Windows on Wash is offline   Reply With Quote
The Following User Says Thank You to Windows on Wash For This Useful Post:
CopperClad (06-27-2012)
Old 06-27-2012, 04:11 PM   #24
Member
 
Join Date: Jun 2011
Location: Atlantic Canada
Posts: 375
Default

Ranch Style Home Attic Ventilation


Quote:
Originally Posted by Windows on Wash View Post
Shingle heat being touted as a destructive force is overused and largely promoted by the shingle manufacturers.

The difference in shingle surface temperatures between a sealed and completely vented attic are extremely slight (usually less than 2 degrees and this is in FL and Vegas). The differences will be even less in Northern climates or areas with shading.
I see this number touted a lot, but that is an average temperature over the entire day, so it's not really a fair comparison. Also it is misleading as people assume it is relative to the exterior temperature. The peak temperature of a sealed attic is about 10 degrees F higher than the vented attic, which is already at 150 degrees F.
shazapple is offline   Reply With Quote
Old 06-27-2012, 10:04 PM   #25
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: VA, MD, DC
Posts: 5,065
Default

Ranch Style Home Attic Ventilation


Quote:
Originally Posted by shazapple View Post
I see this number touted a lot, but that is an average temperature over the entire day, so it's not really a fair comparison. Also it is misleading as people assume it is relative to the exterior temperature. The peak temperature of a sealed attic is about 10 degrees F higher than the vented attic, which is already at 150 degrees F.
Shazapple,

You are correct. I probably should have explained my remarks a bit better as I was speaking to the average peak shingle temperature differences on several measure sides of a roof. I also should have done a better job of stating whether I was referring to Celsius or Fahrenheit but most of the papers switch between the two.

If you look at a roof surface peaks, they were under the most severe of conditions and orientations and the average peak differences probably fall in the 4-7 degree range 95% of the time with the remaining 5% reaching the 8 degree peak temperature differential.

Here are a couple of quote from from BSC study papers:

BSC Research Report 9701 - Peak summer day simulations for Las Vegas showed that the temperature of black roof shingles did not vary by more than 8 degrees F, whether the attics were sealed or vented. The maximum predicted black roof shingle temperature for the sealed “cathedralized” attic was 204 degrees F.

The maximum measured plywood roof sheathing temperature increase of 17 degrees F for the sealed attics is less than the temperature variation experienced by changing from tile to asphalt shingles of any available color. The maximum measured plywood sheathing temperature of
126 degrees F, for the sealed attics during the test period, is well within an acceptable temperature performance range (less than 180 degrees F) of wood-based roof sheathing.


Color, orientation, and pitch have much more to do with how warm a shingle is as compared to sealed or vented attic.

Example, a black shingle on a low pitch and well vented roof will have a much higher surface temperature than a lighter color shingle on a more aggressively pitched roof. A vast majority of the cooling happens to outside and the effectiveness of convection is about pitch and not if the deck is sealed.

If shingle manufacturers were really concerned about surface temperatures, they should start mandating that you can't have a darker shingle on a more shallow roof seeing as that will have much more to do with the peak temperatures that it will reach. After that, they should tell folks South of the Mason Dixon line that they only get the lighter colors.

Until they start doing that, I don't think the shingle temperature argument holds much weight from them.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Windows on Wash is offline   Reply With Quote
The Following User Says Thank You to Windows on Wash For This Useful Post:
AndyGump (06-27-2012)
Old 06-28-2012, 12:21 AM   #26
Registered User
 
Join Date: Mar 2009
Posts: 9,876
Default

Ranch Style Home Attic Ventilation


ulrichfolkers; Do me a favor and go in your attic. Look for all the soffit air holes punched there, you should be able to see them all (if daylight hours....). Or are they sporadic?

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 06-28-2012, 09:14 AM   #27
Member
 
Join Date: Mar 2012
Location: Massachusetts
Posts: 45
Default

Ranch Style Home Attic Ventilation


GBR,

I remember checking the soffits to make sure that they weren't blocked. I did see daylight consistently. The ridge vent is the "steel wool" type material. Maybe the vent is clogged or compressed too tightly when the cap shingles were nailed?? Interestingly, I found an old post that had your DNA on it in which "ridge vent clogging was spoken about":

ridge vents

I would have no problem replacing the existing ridge vent with say the Shingle Vent II or Cobra or something comparable (perhaps I should do this anyway being it's only 8 feet). But, I just can't seem to get past the fact that there's only about 8 linear feet of ridge venting in my hip roof, and, when you compare that to A frame roofs, A frames can have 30 or more linear feet of ridge venting. That's quite a bit of a difference. That's why I was giving serious consideration to adding some louver vents.

I hope what I'm proposing to do will improve the situation even if it's only a slight improvement. That being said I really value input from this group. I want to "go to school" here from the knowledge graciously shared here by the group.
ulrichfolkers is offline   Reply With Quote
Old 06-28-2012, 11:27 PM   #28
Registered User
 
Join Date: Mar 2009
Posts: 9,876
Default

Ranch Style Home Attic Ventilation


I think Andy mentioned the Code with 3' rise space between the intakes and exhaust and 50-80% more exhaust with the 1/300, otherwise you need 1/150 (with 40/60); http://publicecodes.citation.com/ico...006_par001.htm

Install some "turtle-backs" (static box vents) for more exhaust, to balance the ratio. Remember when figuring your NFVA of the soffits, the 1 in 3 vinyls are only 1.56 NFVA per ft., and the full perforated vinyls (3-4") are only 4.68 NFVA per foot- so you need 2' deep soffits (times both sides of house) with full perfs (every one) to match a new ridge vent with baffles at 18 per foot. Change out the mesh for a: http://www.buildsite.com/pdf/airvent...otes-20924.pdf

Quite the difference: http://www.youtube.com/watch?v=rE6fyWHfTXc

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 06-29-2012, 10:10 AM   #29
Member
 
Join Date: Mar 2012
Location: Massachusetts
Posts: 45
Default

Ranch Style Home Attic Ventilation


Gary,

Man....This stuff is a "Science" all of its own. The Youtube video was very enlightening. I'm definitely going to replace my ridge vent with Shingle Vent II, along with adding some turtle vents.

I sure have learned a lot here. Anybody else want to "Vent" here? I couldn't resist. My wife tells me I'm a Wise-a**, But humor keeps me sane!

Steve
ulrichfolkers 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
Attic Ventilation Issue After New Roof PCinCT Roofing/Siding 5 01-19-2012 08:50 AM
Garage ceiling insulation MNHouseRepair Insulation 16 12-05-2011 02:57 PM
Insulating Interior/Exterior Wall Cavity? Old Home from Attic HandyFrank Building & Construction 3 02-07-2011 10:49 AM
Improve attic ventilation? Greenmaze Roofing/Siding 28 07-22-2010 02:16 AM
Attic Ventilation Question handy man88 Roofing/Siding 10 02-12-2010 10:50 PM




Top of Page | View New Posts

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