i just figured it out with a careful reading of the whole chapter. where the roof meets from the house to the porch is a valley, therefore the membrane is required regardless of where it is. it clearly is not there since it would be preventing the moisture from forming by sealing itself. if i am wrong please correct me. it’s a weekend so i have some time on my report.
The typical cause of frost in the attic is warm moist air from the conditioned space leaking into the cold attic. This condition can be made worse if the attic has poor ventilation. A roof leak could also cause frost in the attic if there is melting and then refreezing, but it would be localized to the area of the leak. If the frosty nails are observed in a large area, I would not be focused on a roof leak.
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the frost wasn’t in the attic, it was in the porch area. i couldn’t get to that area of the attic due to safety concerns but took some pictures that were inconclusive from about 15ft away. i didn’t observe frosty nails at all until she showed me a picture she had taken. the roof has decent ventillation in the form of soffit vents every third rafter and a ridge vent running the entire length of the home.
the only things i observed were the gaps between shingles, and the long overhang into the gutters and off the side of the roof, but it wasn’t excessive, just a little long. i am tempted to just write it up like i have it laid out since the transition of roof types is a valley. that is the question now, is that considered a valley since the roof has two different slopes there?
On the ceiling then I assume? Do you have a picture of the frost?
no, that was hers she showed to me. yes, it was on teh ceiling of the porch, exposed osb with the roofing nails poking through. after looking more closely at the valley definition, it doesn’t work since it doesn’t direct water toward a common draining area. it requires z flashing that appeared to be there but the membrane needs to be there to prevent the moisture. she said it had not done that in the whole time they have been there until they replaced the roof. must have had a barrier on it before.
Asphalt shingles cannot be installed on roofs with slopes less than 2:12. This is specified in both the IRC (International Residential Code) and manufacturer installation guidelines. Insufficient slope leads to poor drainage, resulting in potential water pooling and leakage issues. Even if underlayment is installed, the use of asphalt shingles on low-slope roofs is considered improper.
The current roof issues are likely caused by leaks or moisture absorption due to the low slope. When drafting the report, it is crucial to provide a technical basis and include an appropriate narrative, such as the following:
“The current roof slope appears to be less than 2:12, which does not meet the installation requirements for asphalt shingles. The low slope increases the likelihood of drainage issues, leading to potential leaks or moisture absorption problems. This roof requires corrective measures, including the use of materials and waterproofing systems suitable for the slope. Further evaluation and remedial actions are recommended.”
아스팔트 슁글은 2:12 미만의 경사에 설치가 불가능합니다. 이는 IRC(International Residential Code)와 제조사의 설치 가이드라인에 명시된 내용입니다. 경사가 부족하면 물이 제대로 배수되지 않아 물이 고이거나 누수와 같은 문제가 발생할 가능성이 큽니다. 방수시트가 설치되었다 하더라도, 저경사 지붕에서 아스팔트 슁글의 사용은 부적합합니다.
따라서 현재 지붕에서 발생한 문제는 저경사로 인한 누수 또는 습기 흡수의 결과일 가능성이 높습니다. 보고서 작성 시에는 기술적 근거를 기반으로, 다음과 같이 적절한 네러티브를 포함하여 작성하는 것이 중요합니다.
“현재 지붕 경사는 약 2:12 미만으로 보이며, 이는 아스팔트 슁글 설치 기준에 부적합합니다. 저경사로 인해 배수 문제가 발생할 수 있으며, 이로 인해 누수 또는 습기 흡수와 같은 문제로 이어질 가능성이 큽니다. 해당 지붕에는 적절한 경사에 적합한 재료와 방수 설계를 적용하는 수정 작업이 필요합니다. 추가 검토와 시정 조치를 권장합니다.”
I still this this s why.:
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i know you’re right about what is causing the frost, but would the self-sealing membrane help prevent that and is it required to be there under the rolled roofing? further research found that some makers of the stuff require it be underneath of it but there is no way for me to tell who made it. i am just gonna write up what i saw, and say what i just said. i cannot call it out as being wrong definitevly if i can’t find it written anywhere.
i know it isn’t a great idea to believe everything a client says but if they said the roof had no moldy substance on it for the last 20 years since they covered the porch until the new roof went on i am hard pressed not to believe them and say the roofer screwed up. it’s also easier to believe faulty workmanship when i found this shot of drip edge not lapping the required 2" when looking at the pics again for the report. and the gap in shingles concerned me also as far as letting water under them somehow.
i didn’t find the ones where the shingles lapped instead of butting together but they missed the gaps that i found so it’s a draw.
I can’t see why as the nails area is still going to be cold when the warmth hits it.
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that is what is in my head and i can’t get around it. now i have one very important question before completing my report: why now and not in the past 19 years with the other roof?
I don’t know really. 
Maybe it was just never noticed?
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This is correct. Ice and water shield is required, in most areas, to be installed in all valleys and at the eve edges. In the case of valleys and slope changes, there should be metal flashing as well.
Especially if there is a roof material change, but it does not have to be “Z flashing”
NO. The membrane is intended to prevent roof leaks caused by ice dams. It is not a thermal barrier to prevent the nails from getting cold.
Installation requirements for rolled roofing depend on the AHJ and any local adaptations/amendments to the IRC they may have. Typically, If the rolled roofing is properly sealed at the edges of the eve and at all of the seams, then doubled underlayment could suffice. If it is not sealed at the edge of the eve or at the seams, then ice and water shield needs to be installed.
The biggest problem with the “self sealing” types of ice and water shield installation is it the roofer hardly ever removes the plastic backing that allows it to adhere to the roof sheathing and to a lower course should there be more than one. Granted not all are like this, but many are.
Not necessarily. Some AHJs require that Ice and Water Shield overhangs the edge by 1 1/2" to 2" and adhered to the fascia board under the drip edge, then underlayment is to be put atop the ice & water shield and drip edge. Ice dams that start in the gutter can still push water/ice up behind the drip edge, allowing it to come into contact with the wood structure underneath… However, underlayment should go on top of the drip edge…
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Sounds like some pretty bad ice damming. Those areas should figure that out why. LOL
Just to try and clear this up, the area of concern is in the porch. The porch has exposed osb roof decking. I’m assuming there is no attic over the porch then? You are seeing staining on the underside of the roof deck, which is exposed because there is no attic space? And if I understand correctly, the porch is not heated and is closed off to the indoors?
Ryan. I think you have it. Yeah, that’s what I was figuring anyway.
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It seemed like a long ways to go to get there.
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Right there with you. I even read the whole thread 3 or 4 times.
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if anyone couldn’t tell after post #16 that i was asking about an open ceiling on a porch it damned sure wasn’t due to my explanation, however convoluted it may have been at the beginning. perhaps i should lead with an illustration next time if i can’t use a picture. i cannot get a definitive answer on this from anyone i ask, even the internachi drawing i used to explain it in the report was unclear. i used this:
and this:
even though it is a mixture of the two and i still can’t tell if there is suppoosed to be a membrane there or if it would do any good if it were there. i have plenty of pics of sub-standard installation of the roof along with a roof inspection that also has plenty. i did put in the first paragraph that:
The inspection was requested after a faulty roof installation caused microbial growth on the ceiling of the porch which appears to be a shared piece of wood with the attic. It is threatening to encroach on the living area and needs to be remediated immediately.
and then later in the roofing part i put down:
After my inspection was completed the client showed me the roofing inspection, contract, and email communication between her and the roofing contractor. The roofing inspection found the membrane was missing from under the rolled asphalt roofing as required by the contract and some manufacturers of rolled roofing. As I have no way to verify the brand I cannot verify it should be there, nor did I see it upon my inspection.
The gutters appeared to be installed correctly overall, but there was a negative slope on one section on the east side of the covered porch in the rear of the home and this was verified by a visual sighting of water standing on the low side opposite the drain. After having this issue fixed, I recommend regular maintenance and inspection to have debris and leaves removed from the roof and gutters at regular intervals and after severe weather events by a qualified licensed professional. The following illustrations help understand the roof system.
i’m not going to send the report in until this afternoon but i think it’s pretty accurate considering i couldn’t get to the other side of the attic where the microbial growth was seen on the porch due to safety concerns with broken purlins.
a faulty roof installation caused microbial growth You have said many times here you could not verify or see the installation. By the way, clients lie all the time. That issue could have been preexisting. What was in the scope of work? What was the agreement with the roofer?
It is threatening to encroach on the living area Could you see this in the the attic? When does the outside come inside? Only when interior conditions support it.
I would go back to the basics. Report what you saw and what was reported by the client. This is not a narrative I would publish. Also, I would have returned to the home had the client shown me something I was unaware of. Too many assumptions etc.
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you are correct and i changed that when i finalized it. i still called out faulty installation because i couldn’t help but call what i saw, but i toned down my suspicions to just what was there. i pretty much had to when i couldn’t even get up close to see if it was coming in. that’s why i was having so much trouble with it, trying to make it right when it wasn’t. once i changed that it was easy. had i not had the questions i would not have learned anything. i may have left it as it was instead of doing the right thing. and since i couldn’t get to the place to see it i offered a free re-inspection of that area if she got the framing fixed in the attic.
thanx to everyone for helping. merry Christmas.
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