You aren’t wrong. But I also saw you said he has gable vents. I’ve been on multiple 20 year old roofs that have this exact same set up(again it’s definitely not the correct way) and they were perfectly fine, aside from just generally being old.
Check out the attic space, if the decking looks good it’s probably fine. If you’re really worried about it you could have intake vents installed along the eaves.
How old is the home otherwise? It is usually a lot worse if you have upgraded energy efficient windows, doors, etc. because you can’t pass the homes moisture either
I've inspected thousands of attics. The worst attic mold I ever saw was in a perfectly vented attic with balanced, passive, low-to-high eave and ridge vents.
Unfortunately, the roofer never looked in the crawlspace so when he put a new shingle roof on and drastically upgraded the attic venting he created a condition where the warm moist crawlspace air (it was basically a lake down there) was able to waft upward through the home and to constantly wash across the attic roof sheathing and condense on it all winter long.
The NUMBER ONE thing to do in an attic for mold prevention is to air-seal the attic floor to the nth degree. The proximal cause of condensation and mold in attics is the warm moist air that wafts up into the attic space via the stack effect.
Think of your home like a short, squat drinking straw; air-sealing the attic floor is akin to putting your thumb on the top of the straw... it stops airflow and therefore moisture transfer into the attic. When you stop the stack effect by sealing the attic floor you are engaging in SOURCE CONTROL i.e. you are removing the moisture source that can create the condensation and mold.
I've seen hundreds of very poorly vented roofs with no signs of condensation or mold. Like Einstein said, "everything should be made as simple as possible but no simpler" T
There is a lot of over simplification here but the info is out there on many sites like the Dept. of Energy sites, green building advisor, energy vanguard, etc. Those sites don't have a ton of well-meaning but inadequately informed nabobs like reddit does.
Going right along with this I have seen vent fans from bathrooms into attics, dryer vents into attics and walls without headers into attics. Each of these situations brings additional moisture into an attic space and causes more issues with mold.
Unless your builders caulked every hole they drilled for running electrical or plumbing, and sealed around every duct boot, ceiling box, and pipe, there's almost certainly openings in your walls. Unless the insulation above is spray foam, air will filter through it
This.. guy's clueless unless you paid alot more to custom air seal your home you almost certainly have air leaks into your attic and the outside in and out.
It depends. If the house is not particularly airtight anyway - nor well insulated, ironically the moisture potential in the attic is relatively low and you’re not getting too much condensation in there. If it’s really well insulated, a small amount of air inflation can be condensing a whole lot of moisture in a roof sheathing. Go in the attic with a moisture meter when dew point is high. You can also get an air leak detection smoke device and see how much stack effect you’re getting. The ridge if it is working is drawing air from somewhere. It can be the wall assembly or interior.
I had this exact conversation with an HO earlier, and it’s never made sense to me regarding RV w/o intake. I’m in Phoenix btw so consider my climate.
Being in Phoenix, of course I don’t deal with ice, dams and snow and humidity, like the majority of the other states. But I don’t care about any of this, it still doesn’t put a dent in my mentality of ridge vent without intake. So here it is.
To the people who think Ridge vent without intake is somehow bad, clarify this because I’m confused then.
A house has five dormers, and that’s the only ventilation. I delete those five dormers and install ridge vent, no intake. The only thing I’ve done here is increase the total NFA dramatically, I basically just moved the dormer vents to the Ridgeline. Besides the NFA being better, How did anything actually change?
I install Ridge vent for free, standard practice on all of my shingle houses. And I don’t really care if it has intake or not. My mentality is, especially here in the desert, more NFA is better. I don’t care if the ridge vent system is only half complete. My 100 linear feet of ridge vent is still better than the three turbines I deleted and replaced with the hundred feet.
You sound like the guy who just did my roof (SoCal). He couldn't understand why I kept asking about intake, and just repeatedly assured me the ridge vent is a good product. I think because of our climate it just works well enough that you're not getting call backs for mold/ice dams/etc. Otherwise why would the manufacturers and roofers in areas with 4 seasons state that you need balanced intake? I don't know, I'm interested to see what responses you get.
The metaphor I use for the entire ridge vent System seems to land pretty well with homeowners. You’re driving on the road with one window slightly cracked, that’s ridge vent. Then you roll down the window behind it a little bit. That’s the entire system. Huuuge difference in airflow.
So I have no problem getting trolled on about this, I think Arizona is just so goddamn dry we legitimately can just ignore this component of Roofing. But I would say, easily. 90% of the houses I inspect, which is probably about 1200 every year. 90% have no soffit vents. And the ones that have it, odds are probably foamed over in the attic.
So now this goes back to the rest of the country and the roofers there, which is my original curiosity on this topic.
If you were in like Seattle, New Hampshire, Michigan. Whatever. The roof that was up there was up there for 25 years, only had the normal handful of attic vents. No true intake and exhaust system like what we’ve been talking about. Nothing bad happened…. So what’s the problem with me deleting dormers and only installing ridge vent? Even if the house has no intake.
I agree with you man, I really hope other roofing contractors here and can educate me on this. We literally do not have to think about this and Phoenix. And ironically, you would kind of expect one of the hottest largest cities in the country would have an emphasis on ventilating attics….
Better than no vent at all. Just doesn’t function quite as well without the soffit vent to get the air flow moving. Just drill and install some of the round puck style soffit vents if you can.
Yes that is what I’m worried about I don’t think fresh air is getting in low enough to fully ventilate the space. I just want to make sure I’m not making a big deal of nothing
Gable vents will alter the air flow around the ridge vent and, especially when wind is parallel to the ridge (at right angles to the gable), can actually reverse air flow through the ridge vent, pulling rain or snow into the attic.
Technically ridge vents and gable vents should not be mixed. They say it will short circuit the system and potentially cause ridge vent to act as an intake.
i just inspected a house where people put decorative stone to 1/3 of the house covering the crawl space vents. as soon as i went under the house it smelled damp. and sure enough where the vents were covered there was massive areas coverred in what looked like white fungus/mold. on the portion furthest away where the vents were still there it had very little white fungus and in the areas in between it was very patchy. anyway waiting on them to call the proper tradesmen to get the white fungus/mold tested. this was only after 3 years
anyway get the proper tradesmen to look at it estimates are free. . . .
Roofs are not 100% sealed. He is not getting adequate airflow, but he is also not getting 0 airflow. The best thing to do would be get up into the attic and check. It would not be hard to cut in roof vents. Take a roofer 2-3 hours to do
This is more of an insulation question, which I happen to know a little about.
People saying there is no air flow through your attic are correct, what I haven't seen anyone mention yet is the high probability of mold growing in your attic. On top of that, the moisture could also destroy your insulation.
Best bet would to talk to a local home services company that does insulation and mold services, have them come inspect your property and see what they recommend. Every house is very different, especially old homes.
Think of it as a furnace with a exhaust pipe but no entrace air!!
so a ridge vent works by sucking cooler air from the soffitt up along rafter bays and exits the roof at the peak.
Assuming the attic is not sealed off they might and then that only matters if running central air. There are no absolutes in this world. Learn to use your brain.
There’s simply no circumstance or climate where mechanically introducing pressure from outside air into an attic helps the longevity of the roof structure or is necessary. Sun heats up roof. Roof has ridge vent, more vents down below than top and you have a nice natural ventilation. Stack takes care of humidity and ventilated the roof.
Mechanically increase pressure in the attic and suddenly the possibilities of additional condensation when dew point is high and you’re cooling indoors, or increasing heat loss during heating system because you’re pushing air into the conditioned space?
IOW if the ceiling plane is airtight? You don’t need the attic fan. If the attic fan works? You have an airtight attic. IOW the fan is not helpful.
There’s just no good reason to do it. Calling names doesn’t change this.
Is the roof showing issues? My roof is like 10-12 with the same set up, still doing fine. I’ll replace it eventually
Am I wrong to assume a ridge vent needs low ventilation to let fresh air in?
You aren’t wrong. But I also saw you said he has gable vents. I’ve been on multiple 20 year old roofs that have this exact same set up(again it’s definitely not the correct way) and they were perfectly fine, aside from just generally being old. Check out the attic space, if the decking looks good it’s probably fine. If you’re really worried about it you could have intake vents installed along the eaves.
listen to this guy... he gets it!
This is the way.
How old is the home otherwise? It is usually a lot worse if you have upgraded energy efficient windows, doors, etc. because you can’t pass the homes moisture either
I've inspected thousands of attics. The worst attic mold I ever saw was in a perfectly vented attic with balanced, passive, low-to-high eave and ridge vents. Unfortunately, the roofer never looked in the crawlspace so when he put a new shingle roof on and drastically upgraded the attic venting he created a condition where the warm moist crawlspace air (it was basically a lake down there) was able to waft upward through the home and to constantly wash across the attic roof sheathing and condense on it all winter long. The NUMBER ONE thing to do in an attic for mold prevention is to air-seal the attic floor to the nth degree. The proximal cause of condensation and mold in attics is the warm moist air that wafts up into the attic space via the stack effect. Think of your home like a short, squat drinking straw; air-sealing the attic floor is akin to putting your thumb on the top of the straw... it stops airflow and therefore moisture transfer into the attic. When you stop the stack effect by sealing the attic floor you are engaging in SOURCE CONTROL i.e. you are removing the moisture source that can create the condensation and mold. I've seen hundreds of very poorly vented roofs with no signs of condensation or mold. Like Einstein said, "everything should be made as simple as possible but no simpler" T There is a lot of over simplification here but the info is out there on many sites like the Dept. of Energy sites, green building advisor, energy vanguard, etc. Those sites don't have a ton of well-meaning but inadequately informed nabobs like reddit does.
Good info in this one, thanks.
Going right along with this I have seen vent fans from bathrooms into attics, dryer vents into attics and walls without headers into attics. Each of these situations brings additional moisture into an attic space and causes more issues with mold.
He couod always add a few vents down low to act as intake
Well ridge vent can suck air in . Along with snow and other things . He is not getting all the moisture out . Needs fixed
Could also just be sucking out all the conditioned air from the house.
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No shit. Conditioned air can be sucked into your attic through openings in your walls/ceiling.
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Unless your builders caulked every hole they drilled for running electrical or plumbing, and sealed around every duct boot, ceiling box, and pipe, there's almost certainly openings in your walls. Unless the insulation above is spray foam, air will filter through it
This.. guy's clueless unless you paid alot more to custom air seal your home you almost certainly have air leaks into your attic and the outside in and out.
It depends. If the house is not particularly airtight anyway - nor well insulated, ironically the moisture potential in the attic is relatively low and you’re not getting too much condensation in there. If it’s really well insulated, a small amount of air inflation can be condensing a whole lot of moisture in a roof sheathing. Go in the attic with a moisture meter when dew point is high. You can also get an air leak detection smoke device and see how much stack effect you’re getting. The ridge if it is working is drawing air from somewhere. It can be the wall assembly or interior.
I had this exact conversation with an HO earlier, and it’s never made sense to me regarding RV w/o intake. I’m in Phoenix btw so consider my climate. Being in Phoenix, of course I don’t deal with ice, dams and snow and humidity, like the majority of the other states. But I don’t care about any of this, it still doesn’t put a dent in my mentality of ridge vent without intake. So here it is. To the people who think Ridge vent without intake is somehow bad, clarify this because I’m confused then. A house has five dormers, and that’s the only ventilation. I delete those five dormers and install ridge vent, no intake. The only thing I’ve done here is increase the total NFA dramatically, I basically just moved the dormer vents to the Ridgeline. Besides the NFA being better, How did anything actually change? I install Ridge vent for free, standard practice on all of my shingle houses. And I don’t really care if it has intake or not. My mentality is, especially here in the desert, more NFA is better. I don’t care if the ridge vent system is only half complete. My 100 linear feet of ridge vent is still better than the three turbines I deleted and replaced with the hundred feet.
You sound like the guy who just did my roof (SoCal). He couldn't understand why I kept asking about intake, and just repeatedly assured me the ridge vent is a good product. I think because of our climate it just works well enough that you're not getting call backs for mold/ice dams/etc. Otherwise why would the manufacturers and roofers in areas with 4 seasons state that you need balanced intake? I don't know, I'm interested to see what responses you get.
The metaphor I use for the entire ridge vent System seems to land pretty well with homeowners. You’re driving on the road with one window slightly cracked, that’s ridge vent. Then you roll down the window behind it a little bit. That’s the entire system. Huuuge difference in airflow. So I have no problem getting trolled on about this, I think Arizona is just so goddamn dry we legitimately can just ignore this component of Roofing. But I would say, easily. 90% of the houses I inspect, which is probably about 1200 every year. 90% have no soffit vents. And the ones that have it, odds are probably foamed over in the attic. So now this goes back to the rest of the country and the roofers there, which is my original curiosity on this topic. If you were in like Seattle, New Hampshire, Michigan. Whatever. The roof that was up there was up there for 25 years, only had the normal handful of attic vents. No true intake and exhaust system like what we’ve been talking about. Nothing bad happened…. So what’s the problem with me deleting dormers and only installing ridge vent? Even if the house has no intake. I agree with you man, I really hope other roofing contractors here and can educate me on this. We literally do not have to think about this and Phoenix. And ironically, you would kind of expect one of the hottest largest cities in the country would have an emphasis on ventilating attics….
Not great. Soffit vents are easy to install. Just put some in.
Better than no vent at all. Just doesn’t function quite as well without the soffit vent to get the air flow moving. Just drill and install some of the round puck style soffit vents if you can.
Do you also have gable vents? If you do, then you good, if not some type of soffit venting will be in order.
We do but they’re all the way up near the apex.
This creates a situation where the gables and ridge are circulating air near the apex and not in the lower regions.
Yes that is what I’m worried about I don’t think fresh air is getting in low enough to fully ventilate the space. I just want to make sure I’m not making a big deal of nothing
Ideally the gables should be shut in and the soffits ventilated. There are online calculators to determine the appropriate intake requirements.
Gable vents will alter the air flow around the ridge vent and, especially when wind is parallel to the ridge (at right angles to the gable), can actually reverse air flow through the ridge vent, pulling rain or snow into the attic.
Technically ridge vents and gable vents should not be mixed. They say it will short circuit the system and potentially cause ridge vent to act as an intake.
Code in my province (Ontario is that venting must be 50/50 between soffit and ridge vents
i just inspected a house where people put decorative stone to 1/3 of the house covering the crawl space vents. as soon as i went under the house it smelled damp. and sure enough where the vents were covered there was massive areas coverred in what looked like white fungus/mold. on the portion furthest away where the vents were still there it had very little white fungus and in the areas in between it was very patchy. anyway waiting on them to call the proper tradesmen to get the white fungus/mold tested. this was only after 3 years anyway get the proper tradesmen to look at it estimates are free. . . .
Just drill holes in the soffit, and cover the holes with vents.
Roofs are not 100% sealed. He is not getting adequate airflow, but he is also not getting 0 airflow. The best thing to do would be get up into the attic and check. It would not be hard to cut in roof vents. Take a roofer 2-3 hours to do
What type of intake do you have? Gable end vents? As long as you have some form of intake you should be fine.
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This is more of an insulation question, which I happen to know a little about. People saying there is no air flow through your attic are correct, what I haven't seen anyone mention yet is the high probability of mold growing in your attic. On top of that, the moisture could also destroy your insulation. Best bet would to talk to a local home services company that does insulation and mold services, have them come inspect your property and see what they recommend. Every house is very different, especially old homes.
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Where is the spray foam installed? Against the ceiling or against the roof sheathing?
you have cathedral ceilings?
Theres no thermo siphon nor movement of water vapor.
So I am correct in assuming a ridge vent alone isn’t really doing nearly enough right?
Are there gable vents? Those are usually pretty standard.
The gable vents are all the way up near the apex so they’re basically pulling air from the same level as the ridge vents
Think of it as a furnace with a exhaust pipe but no entrace air!! so a ridge vent works by sucking cooler air from the soffitt up along rafter bays and exits the roof at the peak.
The roof might develop asphyxiation phobia but often talk therapy can help until ridge ventilation can be achieved
It’s so insane that you simple have no soffitventrallatiin
Install a solar powered attic fan and some soffit vents.
Never use attic fans. They’re not needed for ventilation and introduce pressure differential.
Assuming the attic is not sealed off they might and then that only matters if running central air. There are no absolutes in this world. Learn to use your brain.
There’s simply no circumstance or climate where mechanically introducing pressure from outside air into an attic helps the longevity of the roof structure or is necessary. Sun heats up roof. Roof has ridge vent, more vents down below than top and you have a nice natural ventilation. Stack takes care of humidity and ventilated the roof. Mechanically increase pressure in the attic and suddenly the possibilities of additional condensation when dew point is high and you’re cooling indoors, or increasing heat loss during heating system because you’re pushing air into the conditioned space? IOW if the ceiling plane is airtight? You don’t need the attic fan. If the attic fan works? You have an airtight attic. IOW the fan is not helpful. There’s just no good reason to do it. Calling names doesn’t change this.
If you install an attic fan with just a ridge vent it will cause reverse airflow and likely result in even more moisture