The standard intake vent for attics is a soffit vent (also sometimes referred to as an “eave vent”) and it allows for air to enter the attic down low, near the eaves. Intake air is critical to maintaining a proper flow of air throughout the attic space. Air enters low and then escapes out of the attic higher up near the peak of the roof, usually via a ridge vent, an attic fan (which we do not recommend), static roof vents, or a high-mounted gable vent/fan. Remember, it’s a bad idea to mix exhaust vent types (passive vents with active fans). More info that here: Proper Attic Ventilation
Even without soffit venting, it is important to provide an air gap at the soffit level to help keep the roof deck dry. For more information on ventilation and moisture control, read this article I wrote on Proper Attic Ventilation. It’s my position that you should have a proper ventilation system in your attic and that you should always take the time to air seal the floor of the attic (sealing off the living space from the non-conditioned attic space), but in cases where you don’t (or aren’t able to), I want to offer some information and direction.
What do you do if your attic doesn’t have soffit vents and you are unable to add them?
First, let me reiterate that I think you should use soffit vents as your intake source for attic ventilation. If your house has minimal (or non-existent) overhangs that won’t accomodate soffit vents, or you simply aren’t able to install them for some reason, then you have a couple of options to provide intake air inlets low near the roof perimeter.
The two most common options are to:
- Install low gable vents located above the top level of the attic ceiling insulation
- Use “eye-brow” vents that are on the top of the sloping roof surface near the soffit/eave area.
- Focus on the other ventilation you have in the attic.
If you are installing a new roof, consider a drip edge vent. This will allow air to come in under the edge of the shingles, and then enter the attic via a small slot/cut that is about 8” from the edge. Learn more here.
Various exhaust vents can be used in conjunction with low gable vents and “eye-brow” inlets. For example, you can use ridge vents, mushroom cap vents, upper gable end vents/fans, high mounted attic fans, etc. Remember, your main goal is to get air moving through the attic by entering the attic space down low near the overhang/eave level and leaving the attic near the peak of the roof.
Using Gable Vents
For an attic without soffit vents, you may have the option to use gable vents instead. Typically you would have a gable vent on each end of the attic. Normal vented air likes to enter the attic lower down (near the bottom third of the attic ) and as it passes through, it will exit higher up near the top third of the attic space. If you have an attic with no soffit vents but 2 unobstructed gable vents, then you will probably be ok on ventilation. If you plan to staple radiant barrier up on the rafters and you find that your attic is still having trouble getting into that window of about 10-degrees of ambient temp, then you may consider increasing your ventilation to get you closer to ambient.
Using Low/Eyebrow Vents
If a gable vent seems like too big of a commitment or undertaking, consider smaller eyebrow vents that are mounted low on the roof slow so they can act as intake vents. Remember, you want more entry points at the perimeter (bottom) edge of the roof than you want at the exit points at the top of the roof. Most people have plenty of exhaust vents but not nearly enough *intake* vents.
Should You Add a Ridge Vent?
Maybe you’ve considered adding a ridge vent because you’ve heard they’re a good choice but you’re not sure since you don’t have soffits. Let me spare you the headache, if you don’t have soffits, don’t install a ridge vent. A ridge vents works by drawing air upward and out of the attic space. But if you have no intake, where is the ridge vent going to draw the air from? 9 times out of 10 it’s gonna come from your leaky attic floor. This is a huge energy waster that I discuss more in this article: Comfort and Energy Efficiency Tips.
Another option for homes that have no place for intake vents would be to use a modified solar fan. You will reverse the wires to make the fan blow INTO the attic as your intake. If you go this route, you will need additional vents to allow the air to get OUT (I recommend you use static vents for this purpose). This method is called “positive pressure ventilation” and should only be used as a last resort.
Summary
Do you need ventilation in order for radiant barrier to work? No. Radiant barrier does require and air gap to work to reflect heat, just an air space/gap. You can learn more about how that works here: Why An Airspace is Required for a Radiant Barrier.
Ventilation is important and can help keep an attic dry and lower air temperatures, but not having any ventilation isn’t the worst case scenario. If you don’t have soffit vents, we recommend you add some other vents in the lower part of the attic that can function like soffits. For some homes, you could try adding vents to a porch ceiling that could act like a soffit and feed the attic. If none of these options are possible, then we suggest you focus your attention to making sure the floor of the attic space is air-tight by checking ductwork (if applicable), lights/fans/vents protruding wires or hardware into the attic, and any other area of the attic floor where there are openings/holes/seams. A couple of cans of spray foam can go a long way toward helping keep things sealed up air tight.
Remember, what really matters is doing everything you can to make sure that the ceiling under the insulation has no air leaks into the attic, and this is a good practice whether or not you have attic ventilation!
I need help! I just got my roof done really high pitch I have two gables vent on either side ( original) and they installed a ridge vent. I have mild growing probably from before the roof was installed. Will two gables and a roof vent be sufficient. Should I be installing an electric fan?
If you have plenty of intake into the attic (usually via soffit vents), then your ridge vent should work well. However the mold is a concern, so I’d recommend either checking yourself or hiring a professional to come take a look at the attic floor and find the “weak spots” where air could be leaking through so they can seal them up. This is hands-down one of the most simple but effective ways to save energy and stop moisture problems in the attic – air seal that floor as best as you can!
Yes!!! Definitely AIR SEAL the attic floor. This should be a National codes requirement on all new housing!! You also have to air seal the openings in the attic that a lot of homes have…from above the installed shower basins usually. I had these and had to by plywood cut to close opening and seal it. Our electric bill was cut about 40% the year after vs the year before! We waited another year and then added insulation from R7 to R38. The results? It cut our bill by maybe 5%.
Hi Ed,
My home is English Tudor styled and has no overhang/soffit. We also have a furnace and ductwork in our attic. The ductwork has been sealed and insulated. The attic floor is also insulated. We have 3 roof vents, 2 gable vents, a roof fan and a ridge vent. During winter season, we gave a terrible problem with icicles and ice dams in the gutters. We’ve had several roofers out for suggestions and so far none have worked. Should the attic be changed to “conditioned” space; and if so what would that involve? Please HELP!!
Mary – ice damming has to do with having a relatively warm roof (usually from leaking warm air out of the attic floor) and so the solution is to have a super cold roof. Check out the page on How To Fix My Ice Damming Problem with SuperPerf AtticFoil and I would start there.
We have a 1940’s Mansard roof with NO soffits. We are replacing the roof in a couple of weeks. The attic runs hot. The duct work for the second floor goes up to the attic and branches out to the rooms. The attic has a wood floor and minimal insulation. The rafters have none. I have two contractor proposals. One wants to add the ridge vent. The other wants to keep the current type of vents which are turtle vents. The attic currently has NO mold or condensation. What should we do?
If it’s a gable style roof, I’d go with ridge vents. If it’s a hip style roof, I’d use turtle vents or wind turbines. I’d look at adding some lower side intake vents. Look at “edge vents”. There are several different styles/brands. Here is one http://airvent.com/stageit/images/installation_the_edge_vent.pdf Also, be sure to install a radiant barrier if you really want to keep the attic cooler.
Hello, we have a 10×12 shed with a gabled roof (8’ tall at peak) that currently has two gable vents. There are no soffits and no way to add soffit vents. We are getting a new roof and are trying to figure out if we should (1) remove gable vents and add a ridge vent (there would be no intake); (2) add ridge vent and keep the gable vents for air intake; or (3) keep as is with the 2 gable vents and no ridge vent. We are in Houston, so often hot and humid weather. We do have a few spots of mold on the ceiling above the door and above one of the windows, but it wipes right off the painted surface. We used to have a shrub in front of the gable so it could be from that.
We are leaning toward (2) above but would really like an expert opinion. Your input would be appreciated.
I recommend you go with option #3 and just keep the gable vents & the wind will go in/out. On a small shed that size, a ridge vent won’t make a difference compared to the existing gable vents. There is no way to totally prevent mold in a non-conditioned building, but decent ventilation (via gable vents) will help some.
Being in Houston, I definitely would recommend you install AtticFoil in the shed to make it much cooler in summer. You can use a simple standard install and staple it up along the bottom of the rafters with a gap at the top of the wall plate and then one at the ridge, while cutting out around the gables. You can see an install here: How to Install AtticFoil in a Shed
Hi Ed, Hoping you can help me out with my situation. I ran into an excessive amount of ice damming this year with my property. I had additional blown insulation added, although I was told by the insulator that my R value was already quite good and that things appeared to be sealed properly in the attic. The insulator recommended additional gable vents and a few maxi roof vents be installed to assist with getting hot air out of the attic.
I own an older home that does not have eaves ventilation and would be very difficult to have this ventilation added. The home currently has 1, 12×15 rectangular gable vent per side of the home and a couple of small mushroom type roof vents.
I am getting mixed signals from those in the home building industry and the internet, some telling me not to install both gable vents and maxi roof vents as they conflict with each other in getting hot air out, some telling me just gable vents or just maxi roof vents.
Not sure what to do…
I appreciate the help.
Brock
Brock – I don’t ever recommend mixing passive and active vents in the same attic because it almost always leads to problems. Take a look at this article I wrote about the basics of attic venting and see if that doesn’t clear up some of the confusion: Attic Ventilation 101
As a side note, ventilation DOES help with keeping an attic cold (this is how you prevent ice dams in winter) but so does a radiant barrier. I cover how AtticFoil can help with ice damming on this page: How SuperPerf Helps Prevent Ice Dams on Your Roof
Hope those resources are helpful to you!
Hey Ed,
We have a 1940’s garage (650 sq ft) that was converted to an apartment with a cathedral ceiling & no vents. Is it worthwhile to install soffit vents and a ridge vent if there is no air channel? We suspect that there is old fiberglass insulation between the roof and the ceiling. Wondering if a minimal amount of airflow through the fiberglass is better than none? We live in Boise. Any thoughts would be much appreciated.
No, I don’t think the lack of vented air is the problem here – it’s the radiant heat coming in from the roof and it having a pretty direct route to get right into the room. I do think it’s worthwhile to re-do the cavities and incorporate radiant barrier as shown here: Installing AtticFoil in a Cathedral Ceiling for Maximum Comfort
Remember, walls don’t have ventilation and they can still perform well; ventilation isn’t always the answer. I dive into this topic more on this page: Surface Temps vs. Air Temps (Why ventilation can’t solve it all)
Ed, I have a 45 year old cedar shake roof that I will be replacing soon. I do not have any soffit venting installed and am not able to install any. I have 2 gable vents on the front of my house and 2 power vents that are located 18′ and 40′ away from the gable vents. I have been in my attic and never noticed any condensation or moisture. I do have blown in insulation in the attic. What would you recommend for venting with new asphalt shingles? Would it be best to just replace the 2 power vents with newer ones? Thanks.
Since you are using asphalt shingles, you will have a new deck. I’d look at using some type of “shingle over” intake vent. Basically, it’s a slot cut in the deck a couple feet up from the drip edge that will act like soffit vents an allow air to get into the attic. Here is a video showing this type product. (there are other brands/models) If you have a gable roof, I’d use a ridge vent. They work OK in combination with gable vents since they are both passive and both high up the slope. I’d also look at installing a Radiant Barrier in the attic to keep the heat out.
Hello Ed,
I have a split level home with a gable roof. The house does not have vented soffits (they are sealed with wood, not a siding soffit issue). I have gable vents on either side of the attic and a ridge vent. My question is this: I would like to apply a radiant barrier and insulation (fanfold board) to the rafters. What is the best way to apply the radiant barrier and fanfold board to the rafters (which goes first against the rafters, radiant barrier or fanfold board), so that there is still circulation and no issues with moisture? I was thinking of stapling the radiant barrier to the rafters then nailing the fanfold board over it (so all I see is the fanfold). Also, leave the ridge vent exposed and leave about a foot uncovered (no barrier or board) the whole length of the roof where the roof meets the soffit so air can circulate between the rafters. Does this sound correct?
Thanks!
Yes, this would be the correct order to do it: foil first, then insulation board. However, I have to ask why you’re adding r-value board to the rafters? You made no mention of converting the attic space into livable space, so that does not make sense to add it there. If you want to bulk up your r-value, you should add it to the attic floor, where you already have r-value or else omit the board all together.
I need help! 3 years ago I replaced all the soffit covers, facia, facia boards, and gutters. To my surprise, the soffit had no venting. I added about (20) 3″ diameter vents, then installed vented soffit covers. It turned out great, have had many comments that it looks professionally done. 2 months later, I had a new roof installed. Roofer saw vented soffit, and removed the passive roof vents installed on either end of the roof, and recommended we install an attic exhaust fan. So we did. The next winter, it was humid in the attic, so fan was on, furnace turned on, and hot water heater was heating. Started smelling fumes in the basement. Had a furnace guy come out, he said we must have a vacuum issue. So the attic fan is drawing air out, but there’s not enough air coming in, so its creating a vacuum which is causing the exhaust fumes from the chimney to backflow into the vent from the hot water heater. Short of me removing all the wonderful soffit work I did, is there anything I can do?
Yes, take the fan out! Use a passive system and you won’t have issues with “sucking” air out of your home (or chimney). More info on this here: Attic Ventilation – Don’t Mess It Up
Hi Ed – My 1920 craftsman home in northern california has several static exhaust vents and one solar vent, all near the ridge. As far as I can tell, there are no soffit or other intake vents. The attic is BLAZING hot even on mild days, but I have airsealed and recently blown in insulation so the house is well-insulated. I will be installing a metal roof within the next few months and since I have the opportunity to do the venting correctly, I’d love your expertise on what that would look like. Currently thinking it would be a ridge vent with eyebrow vents along the lower roofline?
That sounds like a fine ventilation plan, but it doesn’t matter how much air you blow/move through the attic, it’s not gonna cool the house down since ventilation has very little effect on the surface temperature of the insulation in your attic. See what I mean here? How Much Cooler Can My Attic Be After Installing a Radiant Barrier?
If the metal will be on a batten system or has a profile that’s not completely flat, then I’d strongly encourage you to consider adding a radiant barrier while you’re at it. You can even add it on top of an old shingled roof, so it’s easy to install and durable to work with. More info here: RoofingFoil For Metal and Tile Roofing
Thanks for the article! Our attic had a big mold problem that was just remediated. Previously we had a few gable vents around the attic – it’s a connected attic with different sections from multiple additions.
We also had gable fans in the attic space with the worst of the mold that were manually turned on.
A roofer came by and suggested we put in ridge vents along entire attic which we did. Our current roof can not have soffits.
We’re trying to decide what to do with the gable fans. Should we put in passive gable vents instead of the fans? Will passive gable vents work ok with a ridge vent?
We are working on sealing attic floor
Passive vents will work great with a ridge vent! The key is having plenty of INTAKE air coming in lower, typically via the soffits.
Hi! I bought a 1930s house with a detached 3 car garage. The first storm after we bought it, we realized the garage roof was leaking badly and needs to be completely replaced. It has low slope–maybe 1/12 or 2/12? There is no ridge. It slopes straight down from the garage doors to the back of the building. While we’re replacing the roof, should we add ventilation? What kind? Drip edge vents at low edge and static vents near the top? I’m hoping to use it as a work shop, potentially with a window A/C unit.
Adding airflow will help drop the air temps in the garage, so if you plan on using it to work in, that would be a good idea. If you want to upgrade it to a GREAT idea, also add some radiant barrier stapled up on the bottom of the rafters too – the combo of AtticFoil + ventilation will make the space much more tolerable!
I have a 1929 Spanish style stucco house with a tile roof and no overhang. There are two gable vents but they are obstructed by a chimney. Should I force external air in one and try to suck it out the other end? Or, should I suck air out both ends and allow the fans to suck conditioned air to provide ventilation?
I won’t recommend you “force” air into the attic unless you have an easy path for it to exhaust out. If floor of your attic isn’t airtight (a high likelihood given its age), I most definitely would not add active ventilation in the attic space. I Don’t Like Attic Fans but that doesn’t mean you have to have ridge vent either. Can you increase the size of the gables so they can have more free area for the air to come in/go out?
I had an old roof replaced this past Sept. 35+ years old… leaks occured that started the roof project. I was talked into this popular ridge vent. I asked a lot of questions and I was never actually shown if my house HAS any soffit vents! yikes. I have FOUR dormers mid-level of the attic, and a large fan, not used, with about a 3 ft by 2 ft area at end of attic that is positioned to move air out of the home.
I’m inclined to say to myself I got “taken” but maybe no harm done since the four windows and open space from 50 year old fan not working is enough fresh air coming in. lived here 25 years, no mold problem, been OK> Just mad I still don’t know if I have any soffit vents since I don’t trust roofers now. thanks. Paul
How Ed,
I just found your website 2 days ago and glad I did it. We live in Philadelphia suburbs in a typical builder home built in 1983 of 2314 sq ft. We changed our roof 18 years ago when moving in and it’s time to replace it again with better performing shingles. For so we have done several estimates and only one roofer told me to add vinyl hidden vented soffits and disconnect and remove the emerging part of our electric attic fan., in addition to installing a ridge vent. Few years ago after an independent energy audit we had the attic completely sealed and insulated to reach a R-50, even the access trap . After reading your articles I understand the necessity to install the soffits and probably disconnect the fan but would love to have your opinion . Also does the roofer has to provide you with the exact calculation of the ventilation needed? Thank you.
I live in a single level townhouse with 4 of us in a square. After assessing my attic space I noticed I have 5-6 soffit vents at the bottom of the attic however with the way the space was sectioned off between the 4 units I don’t have any access to the ridge vent up top. Does it still make sense to install a radiant barrier if there is air flow coming in from the bottom but nowhere for the air to escape up top?
Thank you for your time
Yes, with or without air FLOW, a radiant barrier can still reflect radiant heat can and reduce the heat entering the attic. I’d still recommend leaving a gap at the bottom of the install and at the peak of the roof, but even without ventilation, you will see a measurable drop in surface temps. More info here: How much cooler can I expect my attic to be after I’ve installed AtticFoil radiant barrier?
Hi Ed
I have a shed roof over top of my garage, the slope is 2/12.
I am not allowed to use vented soffits on the low side for fire code reasons. The attic space has a fire wall in it so it doesn’t make sense to put gable vents on opposite sides of the building. The low slope prevents me from using an edge vent.
I think my best option is to put eyebrow vents on the roof at the low side and then eyebrow vents or gable vents on the top side. Does this make sense and do you have any suggestions that would help?
Thank you in advance.
Ken
Ken,
You can do this to get some air movement, but it sounds like this may not be enough.
Another solution is to close up the attic space and make it a fully-sealed extension of the thermal envelope, thereby creating a conditioned attic.
Hi Ed-
Appreciate all the advice on this forum! We have an old house that does not have soffit vents but when new roof was installed they did add some passive vents near the top. The only air inlet (since no soffit vents) is a couple of gable vents. I am getting two suggestions from contractors for ways to add better air intake and I need your advice. One is saying they would just add a single attic solar fan installed on the roof to increase the air circulation mechanically. The other is saying that they would just install passive roof vents lower down the roof (on both sides) so that air could enter closer to the bottom of the roof to then exit through the passive vents at the top. I had not heard of the single fan before as a solution. What would you recommend?
I agree with the installers recommending passive roof vents lower down the roof (on both sides) so that air could enter closer to the bottom of the roof to then exit through the passive vents at the top. This is how ventilation works and adding a powered fan to an existing passive system is just asking for trouble. More info here: https://www.radiantbarrierguru.com/attic-ventilation-basic-tips/
Hi Ed:
We have a small 1980 log cabin, one-floor with great room/kitchen on one end and bedrooms on the other end. Original design had an attic above the ceiling; attic was ventilated with passive gable vents on each end. There are no soffit vents, so I’m not sure what the intake design was; air seemed to just pass through from end to end. But no issues, just hot in summer.
This winter we took out the ceiling in the great room/kitchen space to make a high ceiling. Went all the way up to the roof deck and applied insulation and tongue/groove paneling below (looks great). Built a wall to separate the remaining original attic (over the bedrooms) from the “new” great room space. So now the remaining attic only has a single gable vent with no intake. I’m wondering what to do?
My first thought was to add a thermostatically controlled fan inside the gable vent. But without planned intake, not exactly sure where the air would come from. I wonder, would putting a fan on the interior side of that space work? Essentially bring air through the high interior ceiling and pass it through the attic with gable vent outtake? It may also benefit the interior space removing the heat up high. It reminds me when growing up we have an attic fan for ventilating the whole house (pre air-conditioning) which was wonderful.
Another point: we are about to put in a new roof, so I wonder if some type of intake installed with the new roof would be better? I cannot see a way to put in soffit vents.
Greatly appreciate any thoughts. Thank you, Bill
Bill,
I would discuss these issues with your roofer and ask them what options you have with the new roof. I would discourage you from adding a fan to the section with the gable (never a good plan to mix passive and active vents in the same space) – maybe just add another small vent in the same area. An experienced roofer should be able to help you make a plan.
On a 90F day my attic temp reaches 135F.
What is the best way to improve attic ventilation in my gable roof?
I had a new asphalt shingle replaced on my roof a few months ago. This time, they added ice and water shield all over (eave to ridge). The roof has continuous soffit vents but no ridge vent. The eaves stick out about 1.5 feet wide. However, there is no daylight through the soffit vents when I look through them from inside the attic (with attic lights off). The insulation meets the roof without any gap for airflow at the soffit. The attic is tongue and groove. There are no rafter vent baffles.
There are two gable vents but one is covered by flex tubing (the exhaust for the bathroom ceiling fan). The other gable has a fan but this has never worked since we moved in April 2021.
My thoughts…
1. Seal up the gable vents and install a ridge vent. Move insulation away from the soffit with rafter vent baffles. Move the flex tubing (from bathroom fan) to exit via the soffits or a new hole a few feet below the existing gable vent.
Or…
2. Seal up the soffit vents and rely on the gable vents instead. Move the flex tubing (from bathroom fan) to exit via a new hole a few feet below the existing gable vent.
Best,
James
James,
Based on your two considerations and knowing how ventilation works, option #1 is the best one of the two. More info here: Basics of Attic Ventilation
Hi Ed,
I have a 1950s cape cod. It does not have soffit vents, but does have gable vents and an attic ventilator fan. We are about to redo the roof, and I wanted to know if having gable vents alone would be sufficient for ventilation or should we add ridge vents and/or edge vents? Also, I wanted to confirm that removing the attic ventilator fan is the right move.
Does this make sense and do you have any suggestions that would help?
Thank you in advance.
Colin
Colin, you don’t have to remove the fan, but you do need to decide what your exhaust method will be. If it will be the fan, then the gables should be closed and you need to add soffit venting. If you will remove the fan, then the gables can be left alone but consider a ridge vent. Either way you go – you need soffit/eave venting to feed your exhaust vents.
Hi Ed,
New home has cathedral roof with open cell under roof above living space. Attic above attached garage is unconditioned (separate from other attic space by foam wall).
Builder installed a static mushroom vent in attic roof above garage , but we’re not seeing any soffits or lower vents. Will this config move air? It’s scorching up there niw with this crazy Texas heatwave.
Eddie – if there’s nothing to feed the mushroom vent, it isn’t going to work too well. Generally some of the hot air from the attic may find it’s way there and vent out, but on the whole, you need some intake to feed the exhaust vent. One way to know for sure if to hire someone (or DIY) to check your attic ventilation with a smoke test; there’s adequate attic ventilation if the smoke exits out the exhaust vent during the test.
Hello,
I have a vaulted ceiling in a bedroom that terminates at the wall where the attic is. I believe the attic used to extend into the bedroom but was vaulted and the attic sealed off in a remodel. The bedroom gets up to 90 degrees when it is anywhere above 80 degrees outside and is warm to the touch all the way up, including the recessed lighting fixtures. On inspection, there are 3 or 4 rectangular intake soffits feeding the vaulted ceiling from the outside, but the roof does not appear to have an exhaust (the two eyebrows on this roof feed from the attic that was sealed off). What is the fix for this heat? Exhausting the roof with a smartvent or eyebrows? Injecting insulation into the drywall? Thank you
You won’t like the answer, but you probably need to take down the drywall and insulate the empty cavities. If you’re willing to commit to this, this page shows you the best and easiest way to do it right: Insulating a cathedral ceiling for maximum comfort year-round.
Hello everyone. I understand that this is an old post and I hope you can help me. I have a cross-gable roof. No place to install soffit vents. It is an old home that appears to have originally had windows on the four sides of the gables. So across from each other on one run, and across from each other on the other run. Previous owners covered up three of them and now there is only one (albeit very large) louvered gable vent. Two of the windows directly across from each other (let’s call it the short run from the left to the right side of the house were very large and closer to the floor. The other two across from each other (lets call it the longer run from the front to back of the house were smaller and higher up. If I were to open them back up and install windows in similar locations would that work? I will eventually insulate under the roof deck as well as insulate and air-seal the attic floor.
It’s possible! For proper ventilation you need some air intake relatively low in the attic, or across from one another to get a cross-breeze action.
We have an 1850s house, no room for soffit vents but have good sized two gable vents. Original (?) settled rock wall insulation and need to add insulation. We can’t add baffles as there are no soffit gables. The gable vents are at the lowest portion of the attic. I was thinking when we replace the roof, we should install a ridge vent. Good idea or bad? I mean, people have lived in this house for 170 years, no moisture problems. Not interested in making a masterpiece of an old attic!
Ruth, I say if it ain’t broke – don’t fix it! If things are working well as they are, I would leave it be. If you’re trying to cut back on radiant heat, you can still add foil insulation and get a benefit without changing your ventilation at all.
Hello! I have a new 10 x 20 She-Shed ready for insulation. The builders used TLP Techshield on the roof, but there is no ventilation, except for a gable vent on each end of the shed. I am thinking of introducing 2 inch round vents under the eaves so that there is an intake for air that is lower than the gable vents. Is this a good plan? Thank you.
Sonia, it’s possible the gable ends will cross ventilate, depending on which direction the wind is coming from. However, having more intake vents can help too. Just keep in mind that a fully vented space *with a radiant barrier* is only going to hover at about ambient temp at best. If you’re looking to keep things cooler in the She-Shed, you need to consider sealing it up air tight and using some A/C too. More info here: Fully insulating conditioned sheds or buildings
I’ve read through your article and it appears my roofing contractor made a mistake this past summer. He installed a ridge vent but we do not have any soffit vents, only a single gable edge vent ( in the top third if the gable). My formerly cozy house is now very chilly and the heater is running continuously. Is there a shot term solution to fixing this now that it is winter? ( I.e. closing off the ridge). Long term solution? I I have eaves but am not sure if they can soffitted or we should add low gable vent. Formerly I had 3 dormer vents with the gable vent. Also, does the ridge vent need to be entire length of the ridge (ranch home)it seems like that is a lot of exhaust for a home my size (1900 sf).
Don’t close off the ridge – you want your attic to be COLD. It’s a non-conditioned space. If your attic is warm and warms the bottom of a cold roofline, you can create condensation with the right conditions so I would caution you against this. Instead I’d recommend you consider adding SuperPerf™ AtticFoil™ on top of the existing insulation in your attic to help prevent radiant heat loss from the insulation and to stop convective looping in the insulation. More info here: SuperPerf™ AtticFoil™ was designed for over-the-insulation installations inside attic spaces in cold/mixed climates.
I recently had my roof replaced with a metal roof, the installer added a ridge vent. Noticed I do NOT have vented soffits and now I have drastic mold growth in the attic. Will adding soffit vents and killing the mold prevent future problems or do I need to remove damaged decking? Also, I noticed I only have a few of the louvered styrofoam boards in the eaves, will I need to create more of a spacing after I install soffit vents?
I would start by adding soffits and letting it all completely dry out. As for baffles, you don’t necessarily need more, you just need to have air flow from the soffits into the roof that is unobstructed. Hope that helps – good luck!
Hello Ed,
I had recently got my garage insulated. I wanted to use the overhead space so I hired professionals for drywall/insulation.
They ended up using batts to insulate my rafters. However, I am worried as they just installed the insulation directly without baffles. I have no soffit vents but my garage does have a vent (I assume it’s a slate vent) at the peak. I dont think I have any intake or If I did I don’t know where else would it be. Should I be worried for possible mold growth down the line?
Alyssa, if your garage door can open, even just a crack, air will pull into the garage from under the door and go up and out the vent. It should be ok, even though this is untraditional (insulating a non-conditioned space with r-value). Just keep an eye on things and try to crack the door open when possible.
Hello Ed,
We just moved into a house in Connecticut that has been neglected. We are moving quickly to replace the 1950s Balsam Wool insulation (maybe R2 value) with new fiberglass and heat shield foil on attic floor… and then replacing the three-tab roof with GAF architectural shingles, probably black. What’s surprising is that there is evidence of moisture (drips probably from snow melt coming in on roofing nails) but there was barely any mold in the attic to the surprise of roofing contractors, remediators and others we’ve had do work in the home.
I want to improve the ventilation in our attic, but am afraid of messing up a good thing. Our house is a Garrison Colonial (post WWII style) with NO soffits. It faces east and gets passive solar most of the day on the front of the house and on the eastern side of the roof. We currently have two gable vents that are too high to create any airflow from the bottom up… and strangely, we have a ridge vent even though we don’t have soffits. We’re thinking of either:
1. significantly lowering the gable vents on either side and maybe making them a bit bigger
2. or installing GAF Cobra edge vents… although this makes me nervous, as it means cutting significant slits in the roof and seemingly has to be done just right to work properly and not leak.
Any advice you can offer is much appreciated! Many sincere thanks, Liz
Hi Liz, my advice is to SEAL, SEAL, SEAL the ceiling/floor of the attic to not let/minimize any warm-moist getting into attic. Then, add more insulation on the floor and cover it up with our SuperPerf™ AtticFoil™. Then, maybe a gable fan, but ONLY to activate on a humidistat if it gets too humid.
Hello, I hope you can offer some insight. We have a modular home that made in the late 70s. It was built in two pieces and put together on site. The eaves are not vented into the attic and we’re starting to notice moisture issues recently. It’s probably been an issue much longer. We are working on getting a new roof and want to be sure to incorporate better venting, but aren’t sure how. We have two gable vents that my FIL had to install after the fact, and that’s it. We are thinking of installing an attic fan, that seems to be the only suggestion. Can you share any other ideas?
I don’t recommend attic fans, especially if you don’t have adequate intake ventilation. I’d recommend intake vents down low and make sure they don’t get clogged with insulation. This combined with a couple gable vents will work well.
Hello Ed,
I live in Florida and am in the process of building a dis-attached accessory structure (pavilion), with a hip roof that has a 6/12 pitch. This structure does not have walls, will not be closed in, and will not be airconditioned or heated. I have 2″x12” rafter between the roof and where I will be installing Cypress tongue and groove. I am getting conflicting information as to if this space between the roof and T&G needs to be vented. Due to the way it was built a ridge vent is not possible and an off-ridge vent would only vent the section it was installed due to the rafters being flush with the ceiling and not allowing air to pass thru the rafters. I was also advised to not do an off-ridge vent because it is common for birds or squirrels to get in them and with there not being an attic or any way to access that space it could pose additional problems. Does this pavilion need to be vented and if so what are my options? Any advice you can offer would be greatly appreciated. Amy
There is no need to vent the space. If you want to reduce the heat coming through the structure and keeping the area below it cooler, I would install http://www.AtticFoil.com between the roof and the T&G.
I have a 1500 sq ft. brick home in TX that was built in the 70s. It has a L-shaped roof with gable vents at the peaks of the long side of the “L”(north/south). There are 2 whirlybird style vents on the roof also. There are no soffit vents at all. My A/C is struggling to keep up in this triple digit heat even though it is slightly oversized for the house. I’m looking into adding more attic insulation and a radiant barrier to the underside of the rafters, but of course it’s a bit hot for that install currently. Would adding soffit vents help shed some of the heat?
Thanks in advance.
John,
While adding soffits can help keep your attic dry and flush out some of the hot air, it’s not really going to impact the a/c’s working environment. You really need to get a radiant barrier up on the rafters to help BLOCK the heat from coming in in the first place. I dive a little more into the ventilation versus radiant barrier question here: How Much Cooler Should My Attic Be After Installing a Radiant Barrier?
Hi Ed,
I live in southeast Wyoming. My house was built in 1935 with no soffits or eaves. I’m not a professional roofer so I’m not sure if what I said is right. Anyhow my house is hot in the summer. I want to add gable vents to it as the roof doesn’t have anything venting it. I got an asphalt roof. My attic is 850 sqft divided by 300 is 2.8. I was thinking of a two 18×28 vent that is 3.5. Is that too big of a vent or should I stay closer to 3 foot vent? Also how low or high should they be off the floor?
Thank you Greg
Greg – I think the 18×28 will be fine; you can’t really over-vent an attic. Adding some soffit vents would be even better and of course you should DEFINITELY get some AtticFoil in that attic on the roof rafters.
I had a new roof installed three years ago with a ridge vent. I was told we would need to replace our soffit with vented soffit within five years. As we were removing the old soffit, we realized that the eves are closed eves without any venting access to the roof. We have blown insulation in so our insulation by far surpasses the height of the eves. Installing venting panels would have been ideal at the roof replacement had we known about them, but we cannot access the roof from inside, so anything done at this point has to come from the eves. What can we do now to create airflow from outside without going to extreme efforts/cost?
I’m glad to find this article. My 1938 1.5 floor Cape Cod house has no soffit vents and no flow from the kneewall attic up into the top attic. The top attic has radiant barrier and gable vents. The side attic has radiant barrier but no vents of its own. The short sloped wall segments between attics have firewall-like blocks between rafters, preventing flow. Hence the side attic has stagnant air and the sloped, uninsulated wall sections between attics are hot to the touch. Would it be advisable to drill a couple 2″ holes through each block in the slope wall, and likewise in the trim border under the roof eaves to enable entry through the side attic? On the dormer side of the upper floor, I put in a gable vent at each end of the tiny “Devil’s attic,” and that seems to help with ventilation through that awkward tube. Thanks for insights!
Don,
I don’t think it is necessary to add ventilation to a space that is not vented. It’s just a dead air space and that’s OK, yes, even if the air feels stagnant. I would leave it as it is and the radiant barrier should help it get close to ambient on its own. If you need the air temps cooler for storage reasons, maybe relocate the storage.
Hi Ed,
We bought our 1921 house in Los Angeles last year and it has 2 gabled roofs (front half is original, back half is raised addition from the 80’s). A few weeks ago, we replaced the very old insulation with new blown-in insulation and added a radiant barrier. The back half of the house (80’s addition) has soffit vents and 2 solar-powered gable fans. However, after installing our radiant barrier, the new insulation, and air sealing, the insulation guy told us we have absolutely no intake or exhaust vents in the front half of our house (original 1920’s). He said it feels very hot and humid in that area of the attic, and because of the way our house was built, we’re unable to install soffit vents. We’re at a complete loss of what to do in terms of intake and exhaust vents and can feel how hot it is in the front half of our house. We’ve also called around to roofers and HVAC companies but cannot find anyone who installs intake or exhaust vents. Our roof is also apparently only a few years old so we won’t be replacing it any time soon. Do you have any recommendations on how we can ventilate our attic? And any idea of what type of trade will do the installs for us?
Thank you in advance for any help you can provide.
If you have a radiant barrier on the rafters on that part of the roof (or even just laid out over the insulation), you should be able to cut down on the radiant heat gain in there, even if you don’t have any ventilation. In some cases it’s just not possible to ventilate a space and in those cases, you want to do everything else you can to stop heat from coming in and a radiant barrier is the perfect material to do that.
One more thing – consider which direction the front of the house faces. If you have west or south-facing walls, you’re going to feel the heat more on that side of the house since the walls are another surface that absorbs the sun’s heat. If possible, you may consider adding radiant barrier in those wall cavities to further help your temps go down.
Spray foamed the attic, and all the ventilation it had .
Now i have just stale air stuck in the attic.
What should i do ?
Nothing. Spray foaming an attic seals the attic up so there’s not a way to move air through there anymore.
Hello,
Sorry, if this message is late but I’m hoping someone could assist. My friend recently purchased a 1920 home that was refurbished by the previous owner who was the builder. We took notice inside the Attic, where the durovent foam boards are attached to the rafters towards Soffet. We can’t see any light looking through and unsure if there’s any air flow. From the exterior looking at Soffets, the previous owner placed these perforated screens that are attached. Inside the Attic, I used my cell camera facing it inside through the durovent foam boards looking downward hoping to see any light, but No visual at all. So were thinking theres No Air coming through from exterior. There’s a have a humidifier fan inside Attic and it’s set at 90 degrees. Recently had the Attic cleaned out of all Insulation due to a rodent situation. (425 square feet cleaned out completely). We decided to Air seal what we could and also add a fire retardant poly sheeting barrier that was stapled in between joist because we were more concerned if rodents would stain ceiling in the future. We then added unfaced R30 Insulation to cover horizontal and vertical to cover completely for a total of R60. But our concern after all the cleaning, new durovent foam boards, screening off any openings for rodents, 6mm poly sheeting and R30 unfaced batt insulation. Our concern is high on intake ventilation from Soffet, which is not functioning. We were wondering what would you suggest us to do, so we would get a good air flow. Don’t want to see Ice Dams build up or frost on rafters in Attic. (Zone 6, new england)
I meant to say R30 insulation was lay down in a criss cross pattern over each other and not horizontal/vertical. Inside Attic, it’s very humid and previous owner had a humidifier fan installed which goes on during the day/night. After all the cleaning. We actually took some incensed burner and lit them up to see where the smoke flows towards. (Just a simple air flow test). Smoke just lingers and slowly moves towards vent where humidifier fan is facing.
Please advise. Greatly appreciated. Thank you!
Were in Zone 6, New England
Eddie – first things first I would open up the vent covers on the outside eave and check to see if the holes are cut and unobstructed. There’s really no other way to know for sure. If they’re open and unobstructed, then you’re good to go and may just need to add a few more to drive in the air through the attic or you may need more exhaust options. If the smoke is stagnant, then it stands to reason you probably don’t have enough intake. Additionally I would look to add a radiant barrier like AtticFoil’s SuperPerf product on top of the new insulation so you prevent any heat loss from the insulation into the attic, which would warm the roof and can lead to ice dams. More info here and here.
Hey Ed
I have an older home that I recently purchased that recently had the roof redone. Currently the house has soffit vents, a gable vent on each side of the house , a ridge vent (installed w new roof) , a circular Gable louvre in the front and they also have a temp controlled fan mounted in the attic on one of the side gable vents.
I have been reading your info and it seems this may be overkill. Any advice on the best course of action would be much appreciated . I’m a tradesman myself so doing any work is no issue.
Thanks !
It sounds like you have plenty of ventilation to the point of overkill. Keeping the air temperature down in the attic is nice, but it does not do much for the top surface temperature of the insulation. It’s like putting a fan on a sunny driveway – not much benefit. First, I would turn off the attic fan and just go with the other vents. Then check the air temperature. Or, if you REALLy want to make a difference install http://www.AtticFoil.com in the attic.
Hello Guru, We get really bad ice dams on our roof. We hired a company to re- insulate the attic the year after we moved in because of these dams. Our house has no soffits (no overhang). There are gable vents, and a ridge vent however the insulators told us the ridge vent is blocked because of a whole house fan that has been blowing dust up there for years. We do have a cover for the whole house fan – in the winter we have it covered from the hallway ceiling and we have a pink insulation board cover for up in the attic side. But we still get terrible ice dams, damaging our gutters and i fear one particular ice dam will take down the radon mitigation system tube (no attic space there – the bedroom has sloped ceiling). the company took out the batten insulation, and sprayed foam between the joists in a large attic storage area, and in the upper attic they sprayed the loose insulation on the floor. We do get melt pattern from the joist wood that was not covered with spray foam, but the melt for the dams is definitely coming from upper attic.
As noted in your article, and as well from other research, we know the ridge vent is pretty much useless. Are the gable vents the intake? or are they where air escapes our attic? would installing roof vents help prevent the dams? if so, what kind?
Ice damming is caused when the top of the roof warms above the freezing point the the lower part of the roof is below freezing. To prevent ice damming, you want a COLD roof. Many customers have seen a significant reduction in ice damming after installing AtticFoil radiant barrier. I would also suggest checking to make sure you have good attic ventilation. Cold air entering the attic will also help keep the roof COLD.
Hi, I have a house with a gable type roof. It doesn’t have any soffit vents and I cant add them. I just got a new roof. I requested that they put in a ridge vent and 4 low-profile vents down low on the roof, for intake. Instead, they installed the ridge vent and the 4 low-profile vents way up at the top of the roof, slightly below the ridge. I requested that they come back and add 2 additional low-profile vents down low. I’m thinking now that I should add more intake vents. Thoughts on what I should do? I’m in southern CA, so it gets hot in summer. Moisture isnt as much of a concern. Thank you!
There are a lot of variables that can affect the attic air temperature, but usually it comes down to two things: the amount of heat your attic is gaining and the amount of airflow passing through. Proper and adequate ventilation is the key to lowering your attic AIR temperature. So if you’re trying to lower the attic air temperature (different than the surface temps in the attic) then you will want to measure the AIR temp in the attic (with a probe thermometer) after they install the vents and see where you’re at. If you’re not at ambient, you need more air moving through the attic, so more soffits/intake. With enough vents in your roof, you can eventually get that temperature to drop to close to ambient (outside air) temperature. I dive into this topic of air temps, ventilation, and surface temps in more detail on this page: How Much Cooler Should My Attic Be After Installing a Radiant Barrier?