Vents can become clogged by insulation. Perhaps your home is well insulated. But if the insulation stops air from flowing, you could have a serious problem. Rafter air channels ensure a clear path where outside air can move under the roof, keeping the area aired out.
Check if your home has the proper insulation and ventilation. Your soffit vents work hard to keep your air circulated. This keeps your home cool and safe from condensation and mold.
Everywhere that there is an air intake piece soffit , cool air is being brought into your home. This is so that cooler air outside can replace the hotter air in attics. Attic venting baffles channel the air from outside, continuing the circulation. This is what keeps your home cooler. So, while rafter air channels are not required between every rafter, they are necessary for each air intake piece. The general rule of thumb is one soffit intake and rafter air channel for every square feet under the roof.
If your home is in need of circulation, we have a step-by-step guide on how to install attic baffles under your roof.
The simple answer is that for every vent you have, the space between rafters to cover every vent should be covered. Multiply that by how many baffles it takes to cover the space between rafters from the bottom to the top of the roof.
However, there is also a question of personal preference. Perhaps you may want to install additional vents in the future. Maybe you want to maximize how airy it is.
In either case, the more attic ventilation baffles creating airflow, the better. This is also recommended if the insulation on the floor reaches the eaves. If this is the case, attic ventilation baffles will ensure a well-ventilated space for your house. If you go up into your attic, look for baffles between rafters. Keep in mind not all rafter need baffles, just those with intake vents at the soffit. This can be cumbersome since you will need to squeeze to the corners of your attic.
It is recommended you wear a mask and cover skin no short sleeves or shorts to prevent contact with insulation, dust, and debris in the attic. Another reason for the lack of rafter vents may be a lack of intake vents. To verify, remove soffit vent screens — if you do not see a hole cut through to the wood leading to the attic, it is not a vent. Here in the Chicago metro area, this is far too common. Is there something else that could be done?
Thanks, Craig. I am going to add blown-in insulation in my attic. I know I need to install soffit baffles in order to avoid the insulation from blocking the soffit vent.
The challenge is my attic is very low and installation of the baffles is almost impossible. Any suggestion? I currenlty have a powered attic fan near the peak and gabled louvers though not directly accross from each other.. I need to replace some rotten soffits. I currently have no soffit vents or roof vents. As I replace the soffits, should I hadd vents.. Hi Jamie, I would add soffit vents if possible.
The vent fan and natural air currents will draw cool air in from them to lower the temperature in your attic. Good luck with your project! My house has ridge vents at three different levels as the roof profile creates three different ridges. I am assuming if it can be split between the three levels, you would do three separate calculations, one for each amount of square footage the ridge covers.
Is this correct? I live in Colorado arid environment in a small house and have a small attic approx. I do not have any soffit vents or an eave for that matter and just two vents on the side of the house near the top of the attic. I have blown in cellulouse insulation on the floor of the attic. Should I add small vents above the new windows that can effectively vent the area behind the knee walls that would be connected to the small area above the ridge?
Or should I just create my room in the middle that includes all space up to the ridge , effectively separating the attic into three parts — area behind the kneewall on one side, conditioned area, area behind the other kneewall — then just add four vents two on either side of the house at each kneewall? I could by way off base with what is even possible here. Any insight is appreciated I also realize this fairly in-depth, so if anyone had a suggestion on a good book on the subject that would be great too.
Hi Tim, Your problem comes up a lot when converting an attic to a room with a vaulted ceiling, since filling the space between the rafters with insulation effectively eliminates much of the ventilation. Rather than bringing your ceiling to a peak, I would suggest flattening the top to leave room for insulation, wiring, ducts, and venting. In fact if you have all three, flow of air through the attic will not be adequate.
Is there any truth to this? I have all three vent types and currently have a mold problem in my attic that I am remediating and am wondering if I should block off the gable vents and just go with the soffit and ridge vents. Any ideas? Hi Matt, The idea is to create a balanced, natural flow of air through the attic due to cool air coming in through the soffit vents, rising as it heats up, and then exiting out the ridge or gable vents at the top.
Where you can run into trouble is combining ridge vents with a power vent fan, which can reverse the flow of air through the attic, by drawing in air and rain at the top through the ridge vent. Hi, I had aluminum placed over my soffit for appearance, but mostly for additional venting. Granted the aluminum is not pressed up tight to the soffit so air should be able to enter through the other holes, but not sure. Hi Tim, Since most perforated aluminum soffit is set below the existing wood soffit with an air gap between the two, you should figure up the area free air space of all the aluminum soffit for each area of the house, then figure up the area of the holes drilled in that same eave and use the lesser of the two for your vent calculation.
Thanks for the response. Based on the calculation above, I need sq inches. Even if I cut the entire soffit and install the vented aluminum I would only be getting sq inches. Any suggestions? I guess that explains why that room is so hot. You could make all the eaves perforated and drill more holes. If it makes you feel better, I have a similar situation at my house.
The previous owners put up vinyl soffit with a perforated piece every few feet, then blew insulation in the attic which appears to have filtered out over the eaves and probably blocked up any vents in the old wood soffit. Our attic is about square feet. The only vents now are small 1 inch round louvres. Should I replace each of them? I counted 20 total. Is this even enough vents? Or both? How many would I need?
I have been reading the horror stories about icles and mold in the attic. It just the blowm in insulation between the joists on top of the dry wall. It there is a lot of moisture, try lowering the humidity level in your house using the tips found in our article on How to Cure Sweating Windows. If you still have a problem with condensation, consider priming your ceilings with a paint that acts as a vapor barrier, such as an oil-based primer, and topcoat over it with a standard latex ceiling paint.
I just had this argument with my roofing contractor who has the family busines for 60 years installing roofing. I am in the north east in Ontario, The house is dual brick contruction built about 60 years ago.
There bricks go right to the top of the underside of the roof. At lease one quote I received and the most epensive the he said lower vents on the roof would help to try and get airflow from the soffit would be costly, though others say that rain and snow could get in, some suggest knocking out some the bricks to allow air in through the soffits. Never seen any icicles in the attic or outside with my old room, surpisingly.
I would put two or three on each side of your roof. The reason to point the vents toward the house on soffit vents is so that you can not see in and they are less noticable.
Just like when you install wall return vents for your forced air Heating system. It only slopes up the rafters for about 2 ft, to add about 1ft of height to the ceiling.
If i removed this insulation, that would be 2ft all the way across the living room, master bed, and office that would remain uninsulated.
I was on the roof the other day and decided to take a closer look at my ridge vent. I noticed that on the shorter ends perpendicular to the vent run that some ends had a foam piece in them, some had some folded shingles in them and others had nothing.
Should all of the ends have something in them, maybe to keep rain out? Or should they all be open to allow better airflow? I also have a powered exhaust vent that turns on when the temp in the attic becomes hot. Some questions: a. If I add a ridge vent should I remove the power vent? I plan on adding some soffit vents so the Sq footage of the soffit venting matches the ridge venting.
The soffit vents I plan on using are metal with finned intake set at an angle. Should the soffit vent have the slotted angles point towards the house, or away from the house. It appears there may be a correct or incorrect method. I have a ranch style house with a hip roof on one section and am going to have the whole roof replaced. A ridge vent will be added to the main peak, however I would also like to add a ridge vent to the hip portion of the roof since that section is quite a bit lower than the rest of the roof, with no ventilation.
I have heard that this may not be a good idea because water running down the main section of the roof may get under the ridge vent where the two meet. Any comment? I have just finished the attic July of my 85 year old house into a usable living space. Its rather hot in the summer, NJ area. I am in the process of insalling soffit vents, but I am quite afraid that there will not be proper air flow because I do not have a ridge to incorporate a ridge vent.
There are also two dormers on opposite ends of the south and north. What do I do? The contractor do not seem to have an answer that makes me comfortable for how the air will be circulated.
He says that the air will move up from the soffit through the baffles and back down to the soffit. Please let me know if this strategy is reliable, because it makes me nervous since every article I read on venting an attic properly says that the air needs to exit at the top of the roof.
Should I consider installing some type of vent maybe two on each side of the east and west side of the roof that will draw air through one of the soffits? I think that maybe I need 3 or 4 vents on each of the four sides of the house.
I try to calculate based on your instructions and came up with 3 vents— but is that total of 3 vents total around the house, or 3 vents on each side of the house? Plus I may need to place 2 vents on each of the dormers. Can you help me please. Your quick response will be greatly appreciated. Is this strategy good, or is it better to cut out the soffit in a rectangle slightly smaller thanthe vent. Hi Jacinta, For proper natural air flow in and out of your attic to remove heat, you need to not only have soffit vents for the air to enter, but vents at or near the peak of your attic for the hot air to exit.
Soffit vents alone are not enough to provide proper attic ventilation. That means you should have at least 2. The vents should be completely open to the attic, so you should cut out the entire vent opening rather than drilling a few holes.
Does it matter if I spread them out evenly or not? I just gutted out an upstairs room in my Cape style house. I could not drill though the wood from inside. Should I remove the siding to install the vents into the wood, or do they make vents with a sleeve that will not allow bugs and debri?
I have a sq ft attic space and a smaller cathedral ceiling. There is no venting for the cathedral ceiling at all which spans two stories of the house. The attic space has only two gable vents one of which is mostly blocked by a new chimney. With no ceiling insulation in the rooms below the attic this is a project house , these rooms have got as high as degrees F which really shows the need for good attic ventilation.
I have researched attic ventilation a fair amount on the internet and come to the following conclusions. Baffles will be added to every soffit vent between rafters to prevent any air flow blockages from ceiling insulation and to prevent air leakage into the attic area.
I plan on conditioning the attic area at least half of it for storage space. I will be adding fiberglass batts between every rafter over the styrofoam channels followed by a vapor barrier of radiant foil insulation this hold the fiberglass batts in place and contain the fiberglass fibers. In summer the sun is responsible for heating the roof shingles and therefore the attic to extremely high temperatures. In winter, warm moist air from inside the home eventually rises to the attic roof where it condenses with the freezing cold roof sheathing causing wet, rot and mold.
Therefore to me, the most important aspect of attic ventilation is to keep the roof sheathing between ALL rafters ventilated. This also keeps the roof cooler in summer and therefore increases roof shingle life. The ventilation will keep the roof sheathing dry it in winter. Hi Simon, If you live in a cold climate, a vapor barrier should be installed below the attic insulation to reduce the amount of moisture in winter rising up from the heated air inside the house.
This will lower the humidity level in the attic and reduce or eliminate any condensation problems. After cutting your first vent if there is no obvious blockage go into the attic, close the attic stairs and turn the lights off.
Otherwise a baffle and some digging through the existing insulation will be necessary for each vent. First, my house is a ranch style built in It has about sq ft of attic space and a standard pitch roof which means getting over to the soffit is a chore I just did it today to find out this info.
I need proper ventilation in my attic as it is about F on a 95F day. I have crawled up into the attic and see part of the problem. The other issue is that when they ran the insulation they ran it all the way out to the roof line and stapled the moisture barrier to the rafters.
The soffit is vinyl and the vents do go up into the attic I checked with a coat hanger. Is my only option to take apart the soffit so that I can gain access to the vents and cut the insulation back a bit so that I can install some rafter vents or what should I do?
If not, you may be able to use an inspection camera, or a video camera taped to a pole, from the attic to see what the situation is, then use a hoe or stiff rake to clear any insulation from the vent opening.
Florida house here built in I cant seem to find much info on this venting method. Soffit runs continuiously around house, no upper vents ie: ridge,etc.
Do I really need upper vents or is soffit only ok. Hi Bob, Yes, if possible you need both soffit vents to let cool air in and vents gable, ridge, or a power vent near the peak of your attic to let the hot air out to have proper air circulation through the attic. You can find out more in our article on Insulation R-Value. The house has no soffits… All you see when looking up into where the soffits should be are the rafters and the support boards for the roofing material.
She has ice buildup most winters so we are looking to try to stop that. Our thoughts are to install some vents at the very top of the sides of the house, and then install some rigid type of insulation in the attic as the rafters are all open.
Basically creating a cold space from the bottom of the rafters and the roof. I have a 24ft L x 26ft W attic with venting across the peak of the new roof. You can stand up in the attic which is abou 8 ft tall. How many total holes should he drill? That number is divided by 2 so that the ventilation is equally distributed between the soffit and the ridge.
Thanks for your input! I have a new roof, with ridge vent all the way down the peak. My soffits are solid, with no vent holes or perfs. Can I just drill a bunch of small holes in the existing soffitt? I dont want to tear it all down and replace. Good luck with your project.
I am having new vinyl siding, soffitt and new gutters installed on my home. I had soffitt ventilation before they started residing my home. I have have NONE. I understand the recommendations, but is there a required code on having soffitt ventilation?? Would you suggest I insist my installers install soffitt ventilation??
Hi Peggy, Most building codes have requirements for attic venting, but you would have to check your local codes to see what they are in your area. I would call and have the building inspector that should be inspecting your job, and ask them about it. I have a bungalow in Ottawa. My attic space is about square feet. I have continuous openings in my eaves around the circumference of my home covered with perforated aluminum soffit. I have 5 roof vents up top that are covering 9 X 9 inch holes cut in my roof.
I am on the verge of getting 10 to 12 inches of fiberglass blown in and my insulator has told me that he will be installing soffit vent channels or baffles in every single Could you please clarify this for me? A couple of people have asked my question—which direction should the vents face—and the answer seems to be that the openings should face toward the house.
Carlton asked the same question, and Ben answered by saying that he had not found a definitive reason for that answer, and Tony answered the same question from Glen by posting a link to diynetwork, which also gave no explanation.
The pros to point them inward would be in case of blowing dust or extreme rain, there would be less entry into the attic. In addition, if the vented air is moist or has mold or other contaminants, you would want that air to be directed away. My inclination is that they should be pointed out, but I am not an expert in any construction or engineering field.
So I would appreciate a debate here. I do not know, and I would like to hear other thoughts on the issue. Hi George, Thanks for the thoughtful feedback. While I doubt blowing rain would pose a problem if the louvers face out, since the vents are under the eaves, water getting in would be a problem if you use a hose or power washer to clean your siding or eaves. Thanks for the answer. The reason I asked is that I am getting repairs on a house that I inherited, and I should have mentioned that there is no attic power vent.
In other words, without a power vent, it would have to go both ways, depending. There are 12 soffit vents downstairs, and 8 upstairs, and they are the original ones. The house was built in I am replacing all of them—they are unbelievably filthy—and I am using hard-to-find ss screws. I have another question. Ideally, when painting, what I would do, if I were the painter, is remove all the vents and light fixtures, sand, then paint and reinstall all the vents and fixtures.
But I am now wondering, having observed that they just merrily paint over the soffits, if I should attach the new soffits and let them paint the new soffits along with the eaves, using the most expensive Behr product, the one that does not need a primer, or if I should remove all the vents but leave the vents open until they paint, then reattach them, and let the soffits be just naked metal on the eaves.
Are soffits almost always painted in situ or what? George, An attic is almost always warmer than the outside air, due to the sun during the day and the residual trapped heat and gradual dissipation of warm air inside the house at night.
Since multiple layers of paint can cause problems if it builds up too thickly, I would suggest lightly spray painting the vents, either before or after installation if you want them to match the house color. I am re-doing my attic insulation and venting. I have added baffels in every cavity that was possible just about everyone I have done the math and my venting seems to be spot on. My house is pretty much a rectangle and only has soffit vents on the sides and across the rear not 1 vent on the front of the house.
Seems to me like you would want vents on all sides. Should I add vents to the front? Hi Jeff, It would be best to have soffit vents on all the low sides of the roof on your house two sides for gable roof, four sides for hip roof to give an even flow of air. If not, make sure you have enough venting on the other sides to make it for the lack of venting on the front. I find this ridiculous. My house was built in , I have a ridge vent at both peaks of my attic. Front to back above garage and left to right above center of house a sqft ranch.
Anyway, after my own thorough inspection I have found not a single soffit vent! Not even perforated vents!!!
0コメント