# Please help> brand new roof shingle and plywood moldy attic after 1 winter



## adlaury (Sep 2, 2016)

Hello 

I got brand new GAF roof with cobra roll off ridge vent back in April 2015 .
I went up in the attic March 2016 found white mold.later I found out the roofer did not cut any soffit/eaves vent .so they come out cut 50 holes 4" diameter 25 in each side.he also told me to spray with mold killer.here is some pic.

Now sept still moldy....

Please help.....TIA

Also found first rot and cracked in rafters now


----------



## adlaury (Sep 2, 2016)

1/3" gap for ridge vent 6 ft long


----------



## adlaury (Sep 2, 2016)

More pic


----------



## adlaury (Sep 2, 2016)

i know is ventilation issue for sure,he alredady cut soffit vents. any input what else can go wrong? THANK YOU


----------



## craig11152 (Jun 20, 2015)

The gap for the ridge vent is insufficent. GAF wants a total of a 2" opening. If there is no center board as in trusses that is just as it reads. If there is a center board of some sort they want 1" on each side of that board to get the 2 inch total. If the opening isn't big enough the vent will not meet its specs for air flow.

edit: you could get by with 3/4" on each side of the centerboard for a total of 1.5 inches and that would be enough. But a 1/3 of an inch ain't even close.


----------



## adlaury (Sep 2, 2016)

thank you for response, yes there is center beam 1".how u think about GAF roll off mesh vent compared to baffled ridge vent? i see a lots bad reviews about mesh vent


----------



## joecaption (Nov 30, 2011)

Any roof I've seen with that roll venting has that same issue, most of my local roofing supply's stopped selling it because of the issues.
Only thing I install is the baffled vents and never once had an issue.
What do you have for soffit venting, not enough or there blocked with insulation and no roof venting is going to work.


----------



## adlaury (Sep 2, 2016)

the roofer is a joke,he only there 1 hour during installation process and let the subcontractor do their thing the rest of the day.so they did not do soffit vent and other stuff.no one check their work

when i told him about the mold he quickly blame others solar panel this and that. finally thanks to google i found out abt soffit vent t


----------



## adlaury (Sep 2, 2016)

adlaury said:


> the roofer is a joke,he only there 1 hour during installation process and let the subcontractor do their thing the rest of the day.so they did not do soffit vent and other stuff.no one check their work
> 
> when i told him about the mold he quickly blame others solar panel this and that. finally thanks to google i found out abt soffit vent they didnt do.


i will try to have him replace roll off ridge and should i have him pay for mold remediation and insulation also?


----------



## firehawkmph (Dec 12, 2009)

Do you have a problem with excess moisture in your attic to start with? In other words, are your exhaust fans for the bath rooms vented to the outside, not just venting into the attic space? 
Mike Hawkins:smile:


----------



## adlaury (Sep 2, 2016)

No bath fans,with old roof we don't hv issue with moisture no soffit 4 vent box and baffled ridge 1250sq ft no air sealed.

Now we have hv this new roof problem a rise.i just installed 2x bath fan properly vent outside.i may hv to do air seal and add insulation in October


----------



## Windows on Wash (Aug 30, 2011)

Cobra vent is a terrible product as @joecaption stated. Most good supply stores will caution you from buying it. That fact, combined with the lack of proper opening as @craig11152 pointed out is your issue.

Now, without knowing soffit venting, those are your venting issues.

As @firehawkmph mentioned, moisture is the real culprit. Air seal and insulate in conjunction with getting those moisture sources outside and that will solve your issues. 

Sorry for the terrible result, but that ridge vent material is really bad stuff and poorly done here.


----------



## adlaury (Sep 2, 2016)

Is it OK to have soffit cut if there is bath vent 15ft below (1st level bath )? Looks like mold is back after i clean it in may,I hv bi level house

Or should I cover that soffit?maybe I should wait until they replace the mesh ridge

Is 50-60 4" soffit vent is enough for 1250 sq ft attic?

Sorry asking many question, is our first house and 1st re roof


Thanks for you input


----------



## Bud9051 (Nov 11, 2015)

A 6' long ridge vent? Doesn't sound like enough for 1,250 ft²


Although "50" sounds like a lot of soffit vents, some pop-in round vents have only 19% net free area. Here is a link that shows a 4" vent providing only 2.43 in² of vent area. Times 50 and divide by 144 and you have about 0.84 ft² of low vent area.
http://wrs.us.com/product-info/OwensCorning/VentSure System Product Catalog.pdf 

Combine that with the limited ridge opening and it looks like you are short on total ventilation. 

Also, make sure they did not cover the ridge opening with underlayment and forget to cut it back.

Tell us more about the space you are venting and we can provide more guidance.

Bud


----------



## adlaury (Sep 2, 2016)

Ridge vent is all along the roof maybe 50 ft, there is 6ft they only cut 1/3" gap for ridge vent. Soffit vent they cuts 50-60 this year's on the eaves


----------



## Bud9051 (Nov 11, 2015)

Having 6' of ridge vent out od 50' at less than the required gap should not be a problem. But the 50 or 60 4" round vents are still an issue.

At 1,250 ft² of attic floor you should have over 4 ft² of low vent area. If your 4" round vents are similar to the link I posted, check page 9 where it lists the NFA (Net Free Area) for the 4" vent at 2.43 in². That is 19% of the hole size and with 50 of them you only have 0.84 ft² of low vent. Always use the NFA to calculate the resulting vent area.

BUT, there is still a question as to where that moisture is coming from. What climate zone are you located in, warm, cold, humid, coastal?

Do you have a basement and is ir humid down there?

Are there extra sources of moisture inside the house, plants, lots of cooking, lots of showers?

Is the house air conditioned?

Has the ceiling to attic been air sealed, recessed lights, plumbing penetrations, electrical boxes and wiring, and tops of walls?

IMO, despite concerns about the ridge vent, 50 feet is a lot of ridge and I doubt it is the limiting factor. The limited soffit venting is a factor for sure.

Bud

Bud


----------



## adlaury (Sep 2, 2016)

So u don't think is the cobra roll off vent is the issue?

With our old roof we have the same things no soffit with baffled ridge 4 plastic roof we never have moisture issue in the attic

Will do air sealed and cover all recess lights can(23x no cover in the attic installed in 2012 never hv issue with old roof) the end off the month with r49 insulation, hopefully roofer replace the cobra vent by then.


----------



## adlaury (Sep 2, 2016)

So they replaced mesh ridge vent with snow country today,and i'll have somebody to do air seal, high hats for recesz and add insulation to r49 next week.and stop using wholehouse humidifier and 3 bath fan installed.hopefully this fix the attic mold issue.

Will report after next winter.


Thank you all for your input


----------



## Windows on Wash (Aug 30, 2011)

That should make a huge difference.


----------



## adlaury (Sep 2, 2016)

They reusing the cap shingle,the old holes is very close to tar line or opening.did they supposed to seal it with black jack?


----------



## Dlongo (Jan 19, 2019)

I replaced my roof approx 7 years ago. GaF shingles, under laymount and cobra vent. The old roof had ridge vent but different type. House was built in 1983 with soffits. No gable vents. No issues with mold from 1983-2010. The new roof was installed and recently noticed mold on bottom of plywood and along rafters. Not sure how long it has been there. I live in upstate NY.

I am concerned the Cobra vent is the problem. There is about 1.5 inch cut out on both sides of the ridge. This extends the entire length of the roof. How do I know this is the problem and prove to GAF this product is bad. No insulation stuffed into the soffits. More black mold near the soffits with ice build up near the soffits as well. ice and water shield 6 feet up from bottom. PLEASE HELP!!!!!!!


----------



## Windows on Wash (Aug 30, 2011)

Most of the issues with Cobra Vent are installation related. It can work if installed properly, but that’s usually the first fault of the system.


----------



## Bud9051 (Nov 11, 2015)

As the original poster discovered there were other moisture related issues and we assume correcting them corrected the problem, thus it was not the ridge vent.

Mod may move your discussion to its own thread but for now we can tag onto this thread.

Here are some questions:
1. Describe your house, ranch, two story, and roof slope?
2. Have you verified that the ventilation is working with the new ridge vent? Too often they forget to cut the underlayment back so the ridge is actually open.
3. Are any fans venting into the attic or possible disconnected at some point?
4. Do you run a humidifier in the house?

Minimizing indoor air leaking into the attic along with verifying good air flow for ventilation is what should eliminate your problem.

Bud


----------



## Dlongo (Jan 19, 2019)

Two floors with basement. Contemporary house style. Hot water baseboard heat. Two attic spaces that do not connect. Both bathrooms vent to the outside through the roof. Felt paper is cut at ridge vent. Any other questions. Thanks Dan!!


----------



## Windows on Wash (Aug 30, 2011)

Intake ventilation?


----------



## Dlongo (Jan 19, 2019)

Windows on Wash said:


> Intake ventilation?


Not sure what you mean, sorry. Bathroom vents go to the roof through two separate vents. No make up air vents. No other venting other then the stove vent that exits the back of the house in wall. Also the vent tubes from bathroom are insulated.

Only real difference is the cobra ridge vent. Gaf rep is coming next week.


----------



## Dlongo (Jan 19, 2019)

my number Please don't post phone number Dan


----------



## Windows on Wash (Aug 30, 2011)

Intake ventilation for the home in terms of soffits, gable end, box vents, etc. 



In order for the ridge vent to work, it needs to pull in air to replace the air being vented out.


----------



## Dlongo (Jan 19, 2019)

Windows on Wash said:


> Intake ventilation for the home in terms of soffits, gable end, box vents, etc.
> 
> 
> 
> In order for the ridge vent to work, it needs to pull in air to replace the air being vented out.


No gable ends but soffits the length of the house with 2+ foot overhang. Another roofer thinks the shingles were cut too short from the ridge vent. He thinks water is getting in and cobra vent not working. That is the only thing that has changed from the original roof from 1983.


----------



## Windows on Wash (Aug 30, 2011)

If it worked before, yank that stuff off and get some GAF snow country or otherwise rigid venting in there once you check the cut back on the ridge.


----------



## Dlongo (Jan 19, 2019)

What do I do now? Back side of roof with steeper roof line is leaking but the front that is less of a slant is not leaking. WE have snow on the roof so do I have to let it melt before I fix? Is it likely the rolled cobra vent was installed wrong? Leaking on one side?


----------



## Yodaman (Mar 9, 2015)

Are you sure its leaking and not condensation? In either case, if you peel off the GAF Cobra roll vent, as others have said, replace it with the rigid Snow Country vent. The rolled product has a NFVA of 9" per foot, the rigid Snow Country vent is rated at 18" per foot. Double the capacity. When opened up, insure the sheathing and underlayment is cut back.


That said, if the roof is leaking near the cap, it isn't the fault of the rolled vent, more likely a workmanship problem. But I would still want the other vent if you need to replace.


----------



## Dlongo (Jan 19, 2019)

The only reason I feel it is leaking and less condensation is only one side is affected, the back of the house. As soon as the snow melts I will replace with the new vent.


----------



## ChuckF. (Aug 25, 2013)

Re: "That is the only thing that has changed from the original roof from 1983."

One thing that might have changed is that you may not have previously had gutter flashing, and now because many building codes have changed the roofers added it. Without gutter flashing there is a lot more ventilation through the so-called 'construction gap' where the roof sheathing is loosely laid above the fascia. Depending how big your old opening was, you may have lost a significant amount of venting on the low side.


----------



## Dlongo (Jan 19, 2019)

ChuckF. said:


> Re: "That is the only thing that has changed from the original roof from 1983."
> 
> One thing that might have changed is that you may not have previously had gutter flashing, and now because many building codes have changed the roofers added it. Without gutter flashing there is a lot more ventilation through the so-called 'construction gap' where the roof sheathing is loosely laid above the fascia. Depending how big your old opening was, you may have lost a significant amount of venting on the low side.


We had no change in the gutter flashing. Same as it was in 1983 when the house was built. 

We currently have snow on the roof. The back side has water lines around the all nails that penetrate the plywood. The front is normal. WHY?? More damage near the soffits on the plywood. Ice and water shield 6 feet up.


----------



## 123pugsy (Oct 6, 2012)

Dlongo said:


> We had no change in the gutter flashing. Same as it was in 1983 when the house was built.
> 
> We currently have snow on the roof. The back side has water lines around the all nails that penetrate the plywood. The front is normal. WHY?? More damage near the soffits on the plywood. Ice and water shield 6 feet up.



I bet the front is facing the west. Condensation will occur more on cooler nails than warm ones.


You need to get in the attic and see if there is insulation blocking the vents at the eaves.
Air in = air out


----------



## 195795 (May 24, 2013)

"the roofer is a joke, he only there 1 hour during installation process and let the subcontractor do their thing the rest of the day, so they did not do soffit vent and other stuff, no one check their work"

Who hired the roofer ? Hire Chuck in a truck, get Chuck in a truck :bangin:


----------



## Dlongo (Jan 19, 2019)

123pugsy said:


> I bet the front is facing the west. Condensation will occur more on cooler nails than warm ones.
> 
> 
> You need to get in the attic and see if there is insulation blocking the vents at the eaves.
> Air in = air out


Adding to my tread....I have a salt box colonial style house. As stated after 5 years of a new roof with a rolled ridge vent I developed condensation in the attic recently. 1400 sqft of attic space by measuring the living space below the attic. 
The back of the house is 40 feet long. 

I currently have open soffits with an overhang 28 inches. Each soffit opening is 28 x 4.5 inches and I have 30 of them. That is in the back of the house. Same number in the front. 

I will be changing the entire back roof, ridge with snow country and plywood b/c of mold. 

Gaf states 1/300=19 feet of ridge but 1/150 38 feet of ridge for tighter house. Soffit requirements from gaf requires 6- 16 x8 soffits 1/300 and 12 for 1/150.

So here is why I am so confused.... My soffits are different in design of the gaf soffit design. My 30 soffits have the crimp design, brown aluminum sold on the Home Depot website.

16 x 8 = 128 sq inch.
My soffit each one 28 x 4.5 = 126 sq inch but my design is different then the gaf design. The gaf design appears to let in more air than mine. However if they are similar in air flow as the dimensions above I should only need 12. My house has 60. 30 front and 30 rear. 

I have been told to have the entire 30 foot run front and back to have open soffits. I do not want to have an increase air flow in compared to air flow out. 

Please help !!


----------



## Bud9051 (Nov 11, 2015)

Hi Dlongo,
There are a couple of details we need to change. You mention 1/300 and 1/150 in the calculations. You use the 1/300 when you have a tighter house, thus less ventilation is required.

Most all vents have a NFA (net free area) rating, meaning the area covered needs to be reduced to the actual air flow allowed, bug screens and louvers restrict the flow. So a 
16" x 8" may equal 128 in² but that may only be 64 in² due to a 50% NFA. I use 50% when I can't find the mfg rating.

You also have a salt box with a high soffit and low soffit, they do not provide the same air flow even with the same vent area. I would need an end view of the house to give you an opinion.

A salt box will have a short roof and a long roof. Which one is front and back and which one is steeper and which one has less slope?

The short roof section will usually provide less air flow so I'm trying to determine which one that is before you start replacing things.

There are more details to cover but will wait for now.

Bud


----------



## Dlongo (Jan 19, 2019)

Bud9051 said:


> Hi Dlongo,
> There are a couple of details we need to change. You mention 1/300 and 1/150 in the calculations. You use the 1/300 when you have a tighter house, thus less ventilation is required.
> 
> Most all vents have a NFA (net free area) rating, meaning the area covered needs to be reduced to the actual air flow allowed, bug screens and louvers restrict the flow. So a
> ...


sent you private's message


----------



## Dlongo (Jan 19, 2019)

Dlongo said:


> sent you private's message


Bud,

Some want me to use spray foam. Open cell in the attic roof and completely seal attic. What to do. I agree to air seal but not convinced on foam.

Would like to talk w u Bud you seem very knowledgeable.

Dan


----------



## 123pugsy (Oct 6, 2012)

Dlongo said:


> Bud,
> 
> Some want me to use spray foam. Open cell in the attic roof and completely seal attic. What to do. I agree to air seal but not convinced on foam.
> 
> ...



Who are these "some"?

Seal the attic with open cell? Really?
Closed cell is what you need if you were to totally seal off the underside of the decking.
However, this is generally only done with vaulted ceilings where there is no attic space.


How about posting a couple picks as Bud requested?


----------



## Dlongo (Jan 19, 2019)

123pugsy said:


> Who are these "some"?
> 
> Seal the attic with open cell? Really?
> Closed cell is what you need if you were to totally seal off the underside of the decking.
> ...


I will put together pics of the house tomorrow including the attic. Quote was $5000 open cell and $12350 closed cell.

I have 1200 sqft of attic and as stated 30 triple 4 center perforated soffits. 30 front and 30 rear. Each one is 1.956 sq inches/sq. SO HOW MANY SHOULD I NEED?

PICS IN THE AM


----------



## Dlongo (Jan 19, 2019)

Dlongo said:


> I will put together pics of the house tomorrow including the attic. Quote was $5000 open cell and $12350 closed cell.
> 
> I have 1200 sqft of attic and as stated 30 triple 4 center perforated soffits. 30 front and 30 rear. Each one is 1.956 sq inches/sq. SO HOW MANY SHOULD I NEED?
> 
> PICS IN THE AM


Thank you for you interest!!!


----------



## 123pugsy (Oct 6, 2012)

No matter what you do, open cell is garbage, there is a reason for cheaper cost. I used it in my floors for sound proofing. It doesn't even do that well.


I'm sure you don't need any spray foam. Just need to get to the bottom of your venting issues.


----------



## 123pugsy (Oct 6, 2012)

Dlongo said:


> ...............................
> 
> I have 1200 sqft of attic and as stated 30 triple 4 center perforated soffits. 30 front and 30 rear. Each one is 1.956 sq inches/sq. SO HOW MANY SHOULD I NEED?
> 
> PICS IN THE AM



No idea what these are.


BTW, I would think with your salt box roof, that the 1200 square feet mentioned is actually more than that.


----------



## 123pugsy (Oct 6, 2012)

One more thing. I'm reading from your urgency, that you seem somewhat panicked. Relax, take your time. The mold is not going to get you. It's up there and you're inside. 



Wait until spring before doing anything. As mentioned, the mold can be killed. There should be 1 gallon sizes available for better pricing. Just pour into a squirt bottle.



https://www.menards.com/main/housew...-mildew-killer-32-oz/5010/p-1492064321401.htm




.


----------



## Yodaman (Mar 9, 2015)

Triple 4 center vent is something to look at. It is a triple 4", 12" total width with perf vents in the only the center. And only allowing about 2 inches of NFVA per foot. I would seriously consider replacing it with triple 4 full vent. It will increase the NFVA to about 6" per foot. Relatively easy to do, and along with a new ridge vent should help move air dramatically. But going through the numbers is a good exercise. Learn it, and then feel comfortable about the changes moving foreword.


----------



## Bud9051 (Nov 11, 2015)

Waiting for pictures to verify my thoughts.

Bud


----------



## Dlongo (Jan 19, 2019)

Bud9051 said:


> Waiting for pictures to verify my thoughts.
> 
> Bud


/Users/vikkilongo/Downloads/IMG_2772.jpg/Users/vikkilongo/Downloads/IMG_2771.jpg/Users/vikkilongo/Downloads/IMG_2770.jpg/Users/vikkilongo/Downloads/IMG_2769.jpg


Bud can you see the photos of my house?


----------



## Dlongo (Jan 19, 2019)

https://www.diychatroom.com/attachm...nt.php?attachmentid=549741&stc=1&d=1549903284


----------



## Bud9051 (Nov 11, 2015)

Ok, so where is the leak/moisture issue?

Bud


----------



## Dlongo (Jan 19, 2019)

Moisture is on the back go the house.


----------



## Bud9051 (Nov 11, 2015)

Does the ventilation from the back soffits have an air path all the way to the ridge. You mentioned two separate attics?

Bud


----------



## SeniorSitizen (Sep 10, 2012)

adlaury said:


> i know is ventilation issue for sure,he alredady cut soffit vents. any input what else can go wrong? THANK YOU


Are we certain it's a ventilation issue. Lets think and work in reverse of how that possibly several years old house was vented, insulated and all that good stuff before the mold issue begin.


----------



## Dlongo (Jan 19, 2019)

Bud9051 said:


> Does the ventilation from the back soffits have an air path all the way to the ridge. You mentioned two separate attics?
> 
> Bud


The back does but the front soffits do not directly communicate.


----------



## Dlongo (Jan 19, 2019)




----------



## Dlongo (Jan 19, 2019)

SeniorSitizen said:


> Are we certain it's a ventilation issue. Lets think and work in reverse of how that possibly several years old house was vented, insulated and all that good stuff before the mold issue begin.


The ridge vent looks flat and compressed as compared to the ridge from 1983. Also on the fireplace side of the house I do have a gas fired furnace Buderus unit that vents very close to the back of the house......


----------



## Dlongo (Jan 19, 2019)

This vent was pointing to the right yesterday. It is close to the back of the house where all of my problems are. Even that side of my house. Thoughts??


----------



## Bud9051 (Nov 11, 2015)

You said "The back does but the front soffits do not directly communicate."
Can you explain?
Common for side attics to pass their air flow between rafters just above existing insulation.

Bud


----------



## Dlongo (Jan 19, 2019)

Bud9051 said:


> You said "The back does but the front soffits do not directly communicate."
> Can you explain?
> Common for side attics to pass their air flow between rafters just above existing insulation.
> 
> Bud


The front has a crawl space that runs the width of the front of the house. We have no baffles but I am sure air gets in between the plywood and the insulation. We have 25 feet of potential air flow from the front to the ridge vent. We r putting in baffles now.


----------



## 123pugsy (Oct 6, 2012)

Off the topic, but your chimney needs some attention while you are working outside.
Is it an oil furnace by chance?


----------



## Yodaman (Mar 9, 2015)

The last pic in post 51 shows a window just to right of a chimney. By looking at the placement of the window tells me the cavity depth, ceiling to roof deck may be shallow.
Within that space there needs to be room for a air gap plus adequate insulation.
What climate zone are we in here. Or general location/state?
Lack of insulation and air sealing is one of the primary cause of condensation which of course leads to mold.


----------



## Dlongo (Jan 19, 2019)

123pugsy said:


> Off the topic, but your chimney needs some attention while you are working outside.
> Is it an oil furnace by chance?


Well I'm spending money so what should I do w the chimney? That is efflorescence.Water getting in from the crown?


----------



## Dlongo (Jan 19, 2019)

Yodaman said:


> The last pic in post 51 shows a window just to right of a chimney. By looking at the placement of the window tells me the cavity depth, ceiling to roof deck may be shallow.
> Within that space there needs to be room for a air gap plus adequate insulation.
> What climate zone are we in here. Or general location/state?
> Lack of insulation and air sealing is one of the primary cause of condensation which of course leads to mold.


That room is my sons room. It is 20 x 8 with a cathedral ceiling. 2 x 6 rafters. Was planning to put in rock wool r23 w/ certeented membrain and baffles. That is how it is spelled.


----------



## Dlongo (Jan 19, 2019)

Dlongo said:


> That room is my sons room. It is 20 x 8 with a cathedral ceiling. 2 x 6 rafters. Was planning to put in rock wool r23 w/ certeented membrain and baffles. That is how it is spelled.


zone 5


----------



## Yodaman (Mar 9, 2015)

Dlongo said:


> That room is my sons room. It is 20 x 8 with a cathedral ceiling. 2 x 6 rafters. Was planning to put in rock wool r23 w/ certeented membrain and baffles. That is how it is spelled.



R23 in a ceiling? This is not enough for most of the country. 

General location or climate zone?


Regarding the chimney, anything venting into it?


----------



## Dlongo (Jan 19, 2019)

I was told by the town of ulster that the new code does not require a vapor barrier on the ceiling of the attic plus r48. I only have 2 x 10. NO VAPOR BARRIER????


----------



## Dlongo (Jan 19, 2019)

Let me be clear....my2nd floor bedrooms do not need a vapor barrier in the ceiling.


----------

