Attic Ventilation - Ridge and Soffit Vents

What about ridge vents when you have cathedral ceilings. are they needed

Armand,
They are a decent idea in that situation.

An older house was constructed with 4x3's rafters (beams) running hoziontally, 48 inches on center. Ignoring "code", would a ventilation solution be to install 2 vents per section?

A two story 2nd house on the same property has a one story addition with a low pitch roof butted to the main house on two sides, and of course no vents. To complicate matters, there is a wood deck over (and supported by) the 1 story addition. Since I have to replace the roof entirely and it has (provisions for) lower soffit vents, what upper ventilation product is best for this 10x10 room?

Mr. Olsen,
It sounds like a decent solution.

Within the past two years we had new roofing paper and shingles installed on our 9/12 pitch roof. This was not an overlay. At the same time we had the turtle vents removed and continous roof vents installed. We left the soffit vents and the gable end vent on the north east side intact (only one gable end because of chimney). Shortly after the shingles were installed we climbed through the access hole to check the inside of the roof. We found a great deal of mold, primarily over the bathroom located on the south west side of the house. However, we feel certain the mold was there before new shingles were installed.

We treated the mold with a solution of bleach and water which killed the mold. We checked a few months later and the mold had not reappeared.
Later, I was told that the gable end vent should be closed off as it did not work well with ridge vent. I did close the gable end with foil and duct tape. The soffits are vinyl and have very small vent holes that are not visible under beadwork that runs perpindicular to the house.
We have a r-19 factor attic insulation (at least) on 2nd floor celinig.
The bathroom fan vents empty into the soffit.

Now several months (7 or 8) after we last checked we find the mold is back.

We have questions.

1. Should I uncover the gable end vent even though we have ridge vent in place?
2. Do you feel the bleach and water solution sprayed on the mold with a garden sprayer will defeat the mold? Or are we going to end up replacing the sheeting and shingles?
3. Will an attic vent fan help?
4. Is attic mold a common problem in newer homes?


Thank you,
Bill

Bill,
You need to read ALL of the columns in these categories to get a full understanding of the dynamics of what is going on inside your attic:

Condensation category
Mold category
Ventilation category

This is going to take you several hours and you will be able to apply that time for college credit in Building Science. Just kidding!

Bottom Line: You need to lower the humidity indoors AND you need to have dry, cold air pulled through the attic *constantly* to push out the humid air that comes into the attic from your home.

Hello everyone,
We have an attic that becomes so super heated in the summer that it clearly affects the ac systems performance. I have read everything I can find on improving attic ventilation and everything seems to suggest soffit vents and ridge vents. My house was built in 2000 and has a soffit/ridge vent system in place. There are baffles installed and the soffits are unobstructed. The soffits run the full width of the house as does the ridge vent. However, there are 2 factors that I am thinking are maybe the cause of my extremely hot summertime attic. One thing is that because of a porch off the back of the house there are no soffit intakes on that side of the house, only the front. The second thing is that the house is a cape cod style with an extemely long, high pitched roof deck with black shingles. I am wondering if the the air being pulled into the soffits is so super heated by the time it gets past that long dark roof and into the attic that it really gives no relief to the scorching attic temperature??
Any thoughts or suggestions on what I can do to relieve my problem would be much appreciated.

thanks
Jamie
Virginia

As a layman, I wonder if the superheated attic of Jamie MIGHT be because the insulation was installed tight against the roof, thus not allowing air flow.

Might you use some visual device to check if air is getting sucked into the soffit?

Since your builder omitted soffits on one half the roof, you have to install some "intake". Would explain your "easy bake attic." as much as paragraph one.

Jamie,
You need to read this column:

http://www.askthebuilder.com/690_Hot_Garage_Ventilation.shtml

And to help put this in perspective, you need to think about how hot the surface of a metal guardrail gets on a roadway that has 100% ultimate ventilation. In other words wind is blowing and there is nothing but air around it.

So anyone who ever thinks they will significantly cool an attic that is in direct sunlight needs to do a reality check. The solar heat gain is enormous. And as I say in the column, the best you might ever do is get it to air temperature!

I understand...but with temperatures nearing 155 degrees when it is 90 degrees outside, something must be done...Would a gable vent at each end of the house with a fan pulling air through work or would it totally disable the soffit/ridge vent system that is currently in place? Would it be better to use 2 gable vents without a fan to just allow the necesary intake for the ridge vents in place to work better?

Thanks for you help,
Jamie

Jamie,
I am sorry, but I am trying to help you. I am desperately trying to communicate the *physics* of the situation.

If you want a *relatively* cool attic install *monster* fans that are blowing tens of thousands of CFMs of air. Even with that, you will still be above the air temperature because the roofing is *radiating* its heat........

Jamie, you need to wrap your head around how hard it is to offset the massive heat gain.

I just discovered this website today. It's great! I have an attic that has had condensation issues for the first time. The house was built in 1965 and is about 50 feet long, with a standard roof ridge. We have 4 roof vents, 2 gable vents, and 6 soffit vents on the north and south sides of the house. We recently installed a humidifier and new furnace and have had a hard winter here in Iowa. We discovered water spots on two bedroom ceilings and found condensation in our attic. I had a roofing company today tell me that I had too many escape routes and adequate intake. He suggested blocking the gable vents so air will be forced to come from the soffit vents. Would this be good enough? Thanks!

Tammy,
No. Read all of my Ventilation category columns.

I understand it's important to have an equal amount of intake and exhaust ventilation. It sounds like soffit vents for intake and ridge vents for exhaust are ideal. Our 1980 house had neither, just 3 gable louvers. When the roof was replaced, we had a ridge vent installed. Would it be worth the trouble to close off the gable openings and install soffit vents?

Thanks
DJ

DJ,
Leave the gable vents and add soffit vents.

We have 6 buldings in our apt. complex. Each bulding as an electric fan at the top. We want to eliminate that fan by installing ridge vents on our new metal roofs.
We have soffit vents also. Should that not be sufficient without the electric fan? They are expensive to operate and are very noisy.
Each apt. has 2 bathrooms that have "stink stacks" on the roof. Should not the other bathroom moisture be handled by ridge and soffit vents???

Jacinta,
Ixnay the ridge vents. I am a big fan of Turbine Vents. Read all of my past columns about them.

I HAVE RAIN LEAKS IT COME THRU THE ATTIC VENT & LEAKS DOWN TO A WINDOW UNDER IT HOW CAN THIS BE RESOLVED DO I NEED 2 REPLACE THE ATTIC VENT?

Rob,
Possibly. You need to call in a professional roofer. My Roofing Checklist is the tool you need to find that pro!

I have a house built in the mid 1970's and is a raised Ranch. There are no soffit/undereave vents, and we need to have them installed, YET we have no discernable soffit or eaves on our roof. The roof terminates on the side of the house when the roof meets the siding. The roof's shape is a gable, but what do I do for ventilation if there are no areas on the gable that actually lead into the attic? Thanks!

Eric,
There are inlet ventilation products made for houses with little or no soffits. Visit a supply house that only sells roofing materials.

Hi,
I live in hot and sunny Miami Florida and want to vent my attic but don't know which system is best. Should I go with free flowing turbines or something else? I am also concerned about hurricane season and whether or not they can take the abuse. Any suggestions?

Thanks
John G.

Hi, I Live in Central Florida in a house with all hip roof. R-30 is installed in attic. House has aluminum soffits. I have been opening garage door 1 foot and opening attic access and receive a great deal of positive ventalation thru the ridge vent and 2 off ridge vents. By opening the garage door and access doors the a/c doesn't come on quite as often. Can anything be done to alum soffit to increase air flow? Or is adding batt insulation on the underside of the roof a possibility?
Thank You
Richard

We have a 100 year old home that had no ventilation - and I mean none - for the attic when we first moved into the house. Since then we have installed a powered attic fan and a ridge vent. We cannot add soffits, but were going to add some passive vents to allow air flow to the ridge vent. My question is - our ceiling goes to the rafters and insulation has been stuffed into these cavaties, does it make sense for us to remove some of this insulation to allow air flow or is there some other alternative that would work? Should we remove 3-4 rafter cavaties or is there some rule of thumb involved?

Also, any thoughts on applying the reflective foil insulation to the underside of the roof where possible?

Could gable attic fan be drawing air from ridge vent, thereby creating a conflict. The ridge vent was added during a renovation/addition at which time two attic fans were removed and replaced with the ridge vent. Attic is much hotter and there is a distinct sense of there being no air flow at all.. I live in S/E Virginia in a area that usually has a good breeze which I have heard can cause a back draft along leeward side of the ridge vent (which runs perpendicular to the prevailing breeze. Many thanks

For the last 1.5 years, I've owned a 2 story Cape Cod style house where the steep roof begins atop the first floor walls. In a previous article you suggested turbine vents for removing attic heat for somebody with a similar setup to mine. There are no soffit vents in my 60 year old house and as you described, I think the roof configuration prevents me adding from adding any. The only attic intake air comes from two gable vents. Last year I replaced the roof and a ridge vent was installed. Here is my question (sorry for all the background info).....If I add a gable vent or turbines, will the air flow conflict with the ridge vent? It seems my real problem is lack of airflow coming *into* the attic. Can you make a suggestion to remedy this? How else can I get more air coming into the attic? Thanks in advance.

I have an older house built in the 50s that has Gable vents only. I am looking at putting on a new roof and have a conflict between contractors. One says ridge vent and the other says it is a closed box construction so sofit vents will not work so a ridge vent will not work. Will a ridge vent work with the Gable vents alone or is there something else that would work better. Thanks

I will have a new roof installed which has four turtle back vents. I am considering to have a ridge vent added with the four turtle back vents. Is this a good idea to have both or should I go with the original four turtle back vents?

Mr. Olsen ,
I recentley encountered a situation that I had not seen in 25 years of renavation ! There is a low pitch rubber roof that leads into the gable end of the main house , when the owner renivated the space he had it heavily insulated , with snap vents installed under the insulation and soffit vents .Aproximatley one year later the dry wall ceiling collapsed .The amount of condensation was increadable !looked like there was a major leak in the roof ! My question is , do you have any suggestions on how to vent this roof system that dies into the gable end ? To add to the problem , the roof fases northeast about four hundred yards from from the ocean and needs to be weather tight .
Rick

Hello,
We had severe attic heat in our 1950 cape cod style house and therefore had soffit vents installed and an attic power vent installed near the top of the roof. We also had insulation removed from the interior part of the roof, so the roof could breathe. I can't seem to figure out if it is best to have a soffit vent / ridge vent combination or a soffit vent / power vent combination for intake / outtake of air? Or - should we have a ridge vent and a power vent for outtake? Some articles seem to suggest a power vent and some suggest a ridge vent. We also have gable vents that are open and part of the original construction. Should I block these off? Thanks,

Julia
Charleston, SC

I moved into a Washington DC row house with a flat rubber roof. The inside of the house gets to be extremely hot with no air movement. Hot air accumulates in the upstairs. Can you recommend how we may vent the house in the summer time and Winter?

Thank you very much!

My attic is 2100 sq. ft.with a ridge vent and I have 11 soffitt vents with attic fan on thermostat. I also have 2 louvered screen vents at one end of the attic. A roofer told my neighbor to close off the louvered vents and disconnect the attic fan and add more soffit vents. Is this advisable? appreciate any advice you can give regarding this. Bob in Yorktown, VA

I have ridge vents but the original builder/owner of the home never put in soffit vents. I climbed up on the rood to see if I could remove the existing soffits and replace them with vents and drilling holes.

My issue is that the builder installed the soffits (without vents)so tight that I would have to tear up the metal holding them in. Now not wanting to replace that and due to me having a roof that has many years left, what can I do?

I am installing a new roof. roofing contractor says that I need to block my gable vents and install soffit vents and a ridge vent. he says that the two systems cancel each other. I always thought the more ventilation the better. The gable has a temp controled fan that will come on during summer months. What should I do.

I have a roof with a ridge vent. I also have soffit vents under the eves and gable louver vents.
I have heard that the gable vents should be closed off to make the soffit/ridge vents work to the best.
Is this true?
Thanks

Is there such rule that roofing area less than 300 sqft do not require venting?

We have a 150 sqft roof with fiberglass shingles but no upper venting. Would this void manufacturer warranty?

I just got an estimate on having cellulose insultation blown in to the attic of my 50 year old ranch home. The estimator told me that I have plenty of roof vents but I only have about 1/2 of the soffit vents that I need. Should I consider having my soffits replaced before I get the insulation? I've been considering gutter replacement anyway. Thank You.

I have a cabin with a roof that is pitched (6/12) on all sides, plus an attached back porch with the same pitch but a gable end. The attic and porch are ventilated with a good ridge vent and soffit system. Works great in the summer. However, when we go up in the winter and there is 1 - 2 feet of snow on the roof, I am concerned that the warm air can not exhaust and will eventually create a problem (after two or three days we start to get snow melt and icicles). We do have the recommended amount of attic insulation.

Are my concerns justified, and what, if anything could I do to have ventilation when the ridge is covered in snow?

Thank you for the advice.

Ok im having alot of work done at my house and Im having new siding put on. There is a decorative attic vent on the front top peak of the houe. I have a ridge vent that goes the length of the house. I would really like to take this thing off. Since I have a ridge vent do I need the gable vent on the front of the house or can it be removed?

Thanks
Eric

I LIVE IN SOUTH FLORIDA AND HAVE RIDGE VENTS ON MY ROOF.I RECENTLY BLEW INSULATION IN THE ATTIC AND REALIZED HOW HOT IT IS . WHILE WORKING ON THE OUTSIDE OF MY HOUSE I FELT THE HOT AIR COMING OUT OF THE EAVES VENTS.
TWO QUESTIONS?
SHOULD I ADD TURBINE VENTS TO A RIDGE VENT SYSTEM?
IF THE HEAT IS COMING OUT THE BOTTOM OR EAVES, IS THERE A PROBLEM WITH THE RIDGE VENT?
THANX,MIKE

I'm looking for a 2 or 3" retrofit soffit vent that will slip into a stucco soffit that I will cut.
thank you

Please give me your opinion re: ridge type venting vs. can type venting. We are getting now roof estimates and we have contractors singing the praises of both. Is one better than the other?
Thanks,
Janet

I just had a ridge vent roof installed on my house. My house has a mansard roof. There use to be all kinds of little square vent caps on my original roof and now their are none. I have a second floor bathroom fan and 2 first floor fans, 1 for a bathroom & 1 for my kitchen. Are these fans venting properly without those square caps that where located in different areas of the roof which I'm assuming were there for ventilation purposes? I don't want moisture and mold to appear in my attic. Thank You So Much.

Gwen Hellgeth

I have a high ranch with an attack area 1/2 the house--the living room and dinning area have a cathedral ceiling so the ridge vent and soffet vents are for looks only--I also have a gable fan for the summer--disconnected in winter--it appears to work fine--is the fan needed with the ridge vent and will it harm anything to use it???

I am about to replace my roof do here in Houston TX from Hurricane IKE. I would like to know which is better for improvement. Ridge Vent, Turbine, or low profile vents that I have now. My attic in my 2story is extremely hot in the summer.

Hello,
Should my cape cod have a ridge vent installed? Every roofer I speak with says yes. (I am getting a new roof in the spring of 09) Next month I am also getting a new hi-efficiency furnace and A/C unit, with Energy Star coming in to insulate and air seal. My Energy Star rep/installer says cape cods should not have a ridge vent.
What should I do? I cannot find any forums that gives a definite YES or NO answer to this question. I understand roofs need ventilation, but what should I do? I do have soffit vents and gable vents right now, which roofers say I should block off the gable vents.

Please help. Thank you.
-Justin

Wanting to add more insulation to my attic, I noticed I did not have soffit vents on both sides of my home, just in the rear. I do have two gable vents and roof vents across the roof.
I have two layers of shingles and they are curling. I plan on replacing the roof next season. I'm wondering if the shingles are curling because of poor ventilation or lack of insulation. Could I just install soffit vents where they are not?

I have a furnace in my attic (walk up attic) and I have one small problem area that allows ice dams to build up. What do you think about pluming some hot air from my furnace into the small area to help prevent the water from freezing when it hits that area? I was thinking of building a small enclosure near the soffit vent that I would sent warm air to when the weather warrants?

I am about to finish a bonus room above my garage. It has designed trusses for it with a ridge vent system. The trusses are 8" and I was wondering if I could use 6" kraft faced insulation as it would leave 1 1/2" of gap. I have also heard not to use kraft faced on the ceiling, if I did not use kraft faced I am worried about the insulation not staying in place as is 45 degree angle from ceiling to wall and 6' span from ceiling to wall. I know the ridge vent helps keep air moving from the side eave vents or soffit vents to ridge vent. any help is appreciated.

We are having a new roof installed on our ranch style house.
The roofers we spoke to all suggested a ridge vent. However, we have a fan in the roof that works off of a thermostat.
The attic has the air handler for the central air.
1. Is it necessary to have both?
2. One roofer said he would have to move the fan because it is too close to where the ridge vent would be(about 18 - 20 inches). What are these requirements as far as how close they can be?

I really don't understand how ridge vents can work properly in the northeast. How can you get proper air flow through your attic, when you have a foot of snow sitting on top of your ridge vent? I have icing problems from time to time on my roof during the winter months even though I rake my roof (about 3" back from the eaves), after storms.

I also would like to see comments from a professional on the topic of ridge vents in snow country. My neighbour has ridge vents only. All other roof vents were covered over after a roofing job. Now he has very serious ice dam issues that he never had before. His ridge vents are covered with 6 - 8 inches of snow during most of the winter. Ridge vents don't sound like a good idea to me.

Jamie

With good ridge vents and sofit vent the thing that comes to mind to do is usa a radiant barier to the upper parts of the trusses. i noticed today a product that is sprayed on to the under side of the sheating that acts as a radiant barier. I have no idea if this product works as well as reflective foil material (REFLECTIVE DOWN) works. The black shingles will colect the heat! I have read that the black is good for insuring the adheasion of the shingles with the added heat. Hurricane protection.

Search for spray on radiant barrior. sp

we have a log home in the adirondacks of new york state. the entire house has vaulted ceilings, so we don't have any attic space, just rafters with insulation and a shingle roof. three years ago we had the shingle roof replaced with like material. the only thing that is different is that the new ridge cap is the owens corning one that looks like a loose weave sponge material. the one that was replaced was a metal syle (not really sure the mfg). for the past three years we have had extensive ice build up on the roof, especially more this year. we know there is heat loss, but didn't experience this much buildup with the previous roof. we feel that we have lost ventilation draft with the new ridge cap. can you recommend a different style of ridge cap better suited for vaulted ceilings and a rafter roof?

I have had different roofers push different ridge vents, each claiming their brand was the best. I there an industry "most favorite", or is it really just personal choice. I have a straight ranch with no ridge vent that needs to be re-shingled and I want to have a ridge vent installed. The roofers have pushed both Cobra vents and Shisyle II vents. I hope the last brand name is correct. I can't really read the handwriting. Is there a big difference in quality or visual effect in these two brands?

I have a hip roof, with a very small hip. About 2 feet hip at the very top. I have soffit vents all around. Have 2 or 3 vents on the south side of roof (no power, just brown rectangular vents).
I am in North East in Connecticut.

I see condensation on nails so assuming no effective ventilation.

What is the solution?
Can I have ridge vents on the 4 edges of the long hip roof?
Or should go with a power ventor?
Or just replace the roof with a gable roof, with ridge and gable vent?
Thank you.
RZ

My 1925 semi-craftsmen home has no soffit vents, gable vents, whirly birds, or ridge vent. The attic's been finished (bedroom, office, bathroom, and den.. which was extended to the edge of the roofline). I'm at a loss as to what my ventilation options are. I've called people out; but, no one seems to want to tackle the project. We'll need a roof in the near future and I understand the roof's warranty is void if there's not proper ventilation. To make things more complicated I'm leary to go overboard with ventilation, as the insulation between the rafters and roof appears old and brittle (I don't want all the heat to escape thru the ceiling). Help!

Thanks in advance for any advice you can offer,

Andrew

If the attic space is all finished and you don't have a problem with ice dams or condensation on the ceiling (water spots)...then maybe you don't have a problem. If the washroom area is vented to the outdoors then your largest source of warm vapour is eliminated anyway.

Why not consider reflective barrier on the roof rafters www.radiantfoil.com
If you can keep the heat out in the first place, and also add more soffit vents, then really so much less heat to manage.

How can I install a ridge vent on a roof having cement tile 1/2 round caps?

I'm having both elevations of my 1960's split-level home's roof redone with asphalt laminate shingles (textured). My plan was to have the roofer install ridge vents. The current roof has a power thermostatically-controlled fan on one level and (probably inadequate) turtle vents on the other. There are also horizontal slats with some airflow on the gable surfaces and there are vents placed periodically in the eaves. I'm in Georgia, so ambients can be quite hot. Should I close off the turtle vents and power fan and just use the new ridge vent, forgo the ridge vent, or retain both?

Thanks.
Dan

I'm replacing a two-elevation roof as part of an insurance claim. The existing structures have only limited eave venting, a few turtle vents, one passive gable vent on each elevation, and a powered thermo-controlled ventilation fan on the upper roof deck.

My new roof is slated to get ridge vents and I'm planning on upgrading the eave vents for better flow, but I'd like to know (considering the "short-circuit" theory and laws of thermodynamics, should I close off the turtle vents and powered fan or just consider them additional venting?

Dan

I recently had the roof shingled and the roofer installed 48 feet of ridge vent.the house ends have the standard end vents, about 3feet high and 6 feet wide.Is this sufficennt and compatable ,suitable set up as is?

Any thoughts on adding a ridge vent for a 2100 ft² home that only has 3 "whirly birds" for venting? I do realize that 3 is simply not enough. But the rumors are that whirly birds and ridge vents do not work together, but work against each other. Taking an elementary mind frame to this would seem that it would not matter as long as the hot air has a place to go.

So the question is: Can I leave the whirly birds and add a ridge vent or should the whirly birds be plugged up and then install the ridge vent?

We are getting quotes to redo our roof. There seems to be a difference of opinion regarding roof vents. Some want to install ridge vents and others off-ridge vents. It seems that more feet of ridge vents are required versus the off-ridge. Which do you think is best?

Thanks

I prefer dome passive vents, but they're hard to find for some reason. Whirlybirds have problems in states with severe weather. My attic got so hot you could see the sap sweating out of the wood. I added 3 vents and the temps dropped from 155 degrees down to 120 degrees. There's room for improvement, I'm planning to replace the small slant-backs with larger domes which would effectively double the ventilation.

hi there,

my house doesnt have ridge vent or any vent at all on the roof. My A/C work in the morning tht best and when noon come, the house getting hotter and hotter. night time house temp. 88. u think i should install ridge vent, or motor vent or R30 insulation on the attic? summer here is hot. i dont know what to do. attic no insulation either.. this is older house.

Is there a calculation to use on figuring out the number of soffit vents you need ? I have approx. 4000 sq. ft. of attic space, but presently I have only 14 soffit vents. I've been using 150 sq ft of attic space per soffit vent, therefore I need to add an additional 13-15 soffit vents. Does this sound correct. ?

Thank you.
JR.

My house has wood shake roofing. Should I hire a certified electrician or a roofer to install a roof top attic fan? Or should I hire both at the same time?
An installer who is an electrician sent by Servicemagic wants to bring a roofer to seal the roof after he installs the vent. Do I need to hire two people to finch the job?
Thanks a lot.
Charlie

are solar attic fans a good solution for a very hot attic

Is it advisable to have both a 'ridge vent' and other ventilation systems on a roof, or is it better to use one or the other? thank you

Hello Everyone.

I live in a Houston suburb and has been researching about ways to lower my cooling bills this summer. My house is a 2-storey house built in 2000 with soffit vents along the longer side of the house and 7-rectangular vents installed on the roof plus 1-powered attic fan with 1,650 cfm capacity. I was considering to install a ridge vent on the top but after reading Jamie's post above, I begin to question the effectiveness of the ridge vent. Despite of having the soffit and ridge vent combination in Jamie's house, he still thinks that he has a "super heated attic" in summer? How much hotter could it be when the ventillation combination is different? For my side, before I installed a powered attic fan, I went into my attic and examined the soffit vents and was shocked to find out that the insulation contractor has plugged about 8-ft section of the soffit vents with insulation. I pulled them all out and easily felt the breeze of cooler air coming to the attic. In its place, I installed a 1/2-inch insulation board with aluminum foil on top side for insulation purposes without blocking the air flow. I measured the ceiling temperature underneath it with laser thermometer and I get almost the same temperature as the other sections with R19 insulation in the attic. 3-weeks ago, I installed a wireless thermometer and humidity sensor in my attic and monitor the daily peak temperature & humidity out there, with my powered attic fan set to run when it reaches 105-deg F. So far, my daily readings indicated that when the outside temperature range between 96 to 100 deg F, my attic temperature was between 103 to 111 deg F or an attic vs outdoor temperature difference of +7 to +11 deg-F. Today, 8/1/09, I turned off my powered attic fan and my attic vs outdoor temp difference was +8.3 deg F. Now, I'm starting to wonder whether the use of a power attic fan really makes a big difference or not. At the same time, I am running another experiment of using an aluminum foil installed on top of the insulation and see if it indeed makes a difference relative to the use of insulation alone. I applied an aluminum foil on about 2ft x 3ft section of my attic and placed wireless thermometer underneath that insulation. I also placed another wireless thermometer on another section with insulation only. So far, it appears that the section with aluminum foil is mostly 1-deg F cooler for the most time of the day. Anyway, I'd like to point out that ventilation and insulation alone cannot beat that radiant heat from going into the living space under the attic. Some radiant barrier is needed. Any idea on this?

Hello Tim,

Sorry for my ignorance but I have no idea what are the technical terms for my problem. We bought a 34 year old house and right now the problem is around the roof. Water become stagnant on one side of the roof 'coz of the soffit, i guess. There's no problem on the eaves-trough or the gutter. I dont know what to do and winter is just around the corner. I dont want my whole roof to collapse bcoz of this. Please help me.

What about Power Ventilators?

Will sofit/ridge vents work with gable vents or will the conter act each other

I built a house in 2007. I live in New Hampshire and the winters get pretty cold. I have an orange colored drip coming out of my soffit. It's very strange and can't figure it out. It's leaving the snow on the side of my house with orange drop spots. It's only coming out on one side of my house where my cathedral ceilings are(no attic). The installers of the insulation put in r-38 and also installed a styrofoam vent that is above the insulation. It looks like it's dripping from the styrofoam vent, coming out the soffits. Any suggestions or help would be greatly appreciated. Thank you

How many soffit vents should a home with 2,000 square feet have?

I had my roof replaced a few years ago and the roofers added ridge vents. I noticed that the house does not have soffit vents. Is it necessary to have soffit vents also?

We live in the Phoenix area in a 2300 sf L-shaped ranch-style home with a stucco exterior, a tile roof and an attached garage. There are three triangle gable vents about 20 inches high and 60 inches wide (as seen from the ground). There are six 8x26 soffit vents (builder had them made). One of those soffit vents are placed on each side of the garage. HOA bylaws do not permit turbine-style vents. The house has an R-38+ attic insulation (fiberglass was added once the cellulose settled).

Using the 1 vent per 300 sf rule, would it be beneficial to add three or four or even more 8X16 inch vents along the soffit?

Thanks.

Is that right to install ridge vent and turtle vent together on the roof?

I have a log cabin and have soffit holes on the front and rear of my house. I also have a cathredral ceiling-which means no attic. I want to close up these soffits. If I do what will happen ventilation wise? Another reason is possible bat nesting. I have had 2 bats in my house in the past year and don't want any more and I think one way in is through the soffit. Please let me know what you think.

I recently had a new asphalt roof installed replacing a shake roof, never a problem with ice dams, now I have ice dams and the snow is melting and freezing at the soffitts. I have soffitt vents and 6 can vents about 3 feet down from the ridge. I read your guide for calculating the square footing in the attic but you didn't say where to take the measurements? How do you factor in the roof pitch in the calculations?

Yesterday I asked the question, where do you get your measurements for the square footage calculation. Does it take into account the cubic footage, I have vaulted ceilings so the air space would be less that if the attic floor were flat....I do need some help on the calculations because I think my soffit vents are to small. The builder just drilled holes with a hole saw drill and the holes are only about 2" I have six can vents on the roof.

I have no soffit vents and hard asbestos siding that goes all the way up to the roof can not cut the overhang for it is the tounge and groove for the roof sheeting do I drill holes in the siding for a small round 2in vents or cut the siding and put longer vents in there. Or is there any other way I have 3 vents on the roof the house is 25 by 45 airplane bungalow

Need a new roof and have conflicting info from roofers about ventilation. Our home has no overhang so there are no soffit vents just a full ridge vent, two gable vents and an attic fan. One roofer wants to cut along the eves to make vents while the other thinks we have sufficient ventilation. Who is the right roofer for us?