Freezing/leaking plywood interior of the roof

Approximately year ago I have ordered reroofing work on the split level house with a pitched roof and plywood sheeting. Old roofing materials have been thorn down and new asphalt shingle including ice/water shield up to 3 feet above the edges and around the house as well as ventilation fan and ridge vents. It worked well over the summer and most rains did not make me scared of leaks. During last few subzero temperature days in Midwest (I reside in Chicago, Illinois) I noticed leaks at the ceiling of some spots. I checked the attic and noticed that there are several wet spots with dripping water from the rafters over the flat laid loose insulation above the ceiling. I also got surprised seeing frost around the edges of the roof just above the gutters on inside surfaces of the plywood showing frozen moisture. It covers actually about 40% of the interior plywood surface just about the line where the ice/water shield was installed. I wonder what possibly can cause this destruction and how to go about fixing this issue. The strange part of it is that when reviewed I find that wet dripping occurs only on 2 walls and not all, second where is the frost from and why is that leaking now and not the last summer? I am loosing the roof I do understand, but I sincerely appreciate your opinion advise. I will be happy to email you 2 photos of this problem if you only agree to briefly review it.

Once again, thank you very much

Chris D

Well chris i think we would need more information. DO you have soffit vents? Reason why i ask is you said you have ridge vents. Pictures of the inside of the attic will help out alot. Soffit vents are at the edge of the roof. below the gutter on the overhang. If you do not have soffit vents that is the reason you have all that moisture in your attic. This will cause mold in time. Is the insulation wet now? How much insulation do you have? How big is the cut on the ridge vent? DO the cuts go from either side leaving 2 feet per side at the edge of the roof? Can you send pics of the cut of the ridge vent in the attic? How cold is it there? Where are you at?
You can email me at with pics or you can post them here.

This could be a classic case of a short-cicuited ventilation with a ridge vent AND attic fan.

Email me with those pics, if you like.

I appreciate very much your help on my freezing and leaking roof problem. I’d love to know how to attach a picture in this reply so I could make this exchange of information easier, but I don’t so I took the offer of emailing you the 2 pics which will probably make it better.

In response to questions: Yes, the roof was originally built with the soffit vents around the parameters of the roof of entire house. The lower section of the house has about 10 feet of ridge and there is about 8 feet long ridge vent installed on this part of the roof - which is lower level roof. I did not see any water damage on this part of the house - at least yet and there is no attic on that section of the house. On the higher level of the house roof does have the attic and that is where we experience the problem. There is about 18 inches in width of soffit around the parameter on the higher roof of the split level house. Approximately 22 inches of the overhang is covered with soffit vents on the lower section of the house also vented. The “problem” roof is the higher and attic side of the roof where the pics where taken. There is no ridge-vent installed on this roof section, but there is 16 inch diameter electric fan installed on this roof since no ridge-vent can be fitted due to size and shape of the roof. There is virtually only about 2 feet of ridge on this envelope type section of the roof. Now, the electric roof does not kick in since it is operated with thermostat above like 90 Degrees F in the summer. It is however opened now and does not have any dumpers or closures except the mushroom type cap. I am in Chicago, Il and it gets pretty cold here sometimes. It is about -4 degrees now and last week about the same. Lastly the strange part I also noticed is that the frost and leakages are present only on one wall/side of the roof. Other 3 sides are dry and basically frost free with same insulation, same materials, environment I guess and possibly influence from below living space. It does not appear like its a simple case. Knowing my luck - it will probably not be easy to fix either.

Once again, thanks very much for helping hand and advise in this case.

Stay warm


Like i stated in my email i need additional information to make an educated answer for you. Also like i stated in my email leave me number i can call you at later this afternoon around 3 or so.

is there a bathroom fan exhausting in that general area? also is ther insulation blocking the soffitt vents?

Ya pictures would be helpful But I believe you have one of two things accuring either Ice back up in the affected area or condensation. I know you said that there is 3 feet of ice & water shield on the roof ,often in cold climates ( like here in Michigan) thats not enough . It needs to extend at a Min. of 2 feet inside the interior wall line ,so unless you have 9 inch or shorter overhangs at your eaves 3 feet of Ice & water Shield isn’t enough . However a Condensation problem would be a direct result of inadequate ventilation , which is what I expect the problem is, Just because you have soffit vents & a power vent doesn’t mean you have air-flow ( ventilation) Everything has to be unblocked & open & of an adequate size.
I dont think the problem is going to be hard to fix but it better get fixed , Who roofed it & where is he ? Whoever it is you should have hired someone better, if he was a low ball bid- you got what you payed for , If he wasn’t but he cant be found now or wont respond to your crys for help complain to the BBB & the State Board ,if he wasn’t Licensed —then you deserve this trouble. The thing is the next guy who comes out to fix it ( if you dont Yourself ) should take you to the cleaners. The last guy made all the money , so why does a new guy want to come in & assume all the problems for a few dollars. You need to make the company that did the work —PAY—find away , because if I come out to fix a one year old roof that someone screwed up Im making you PAY
Sorry but thats the realitys of this game you need to actually check out the company you hire , Lots of people think they do ,but they dont , taking the guys word for it isn’t checking him out

I have been chatting via email with this guy and it is a simple reasoning of has a power vent that will not turn on and the soffits are not blocked. Also his insulation is upsidedown.

Me, too, kevin. He does not have the frost in any area predominantly. There is not more frost over the bathroom than the bedroom. It is not heavier at the faart fan vent, in fact there is none at this location, it did not show up until deep freeze, and we have had snow covered roofs lately. Also, look at his pics and see how the water is running from the top of the rafters, but there is no frost on the rafters? Looks like a bad couple of sides of roof to me that didnt show up in the rain due to water actually running off. I bet he is getting enough icing to seep upwards. It is only on two side of a hip roof on the sections away from the bathroom, and over his bedroom…unless they GET DAYOWN heavy duty in the budoir. :slight_smile:

Good evening Guys

I wanted to thank you all for sharing your experience as well as opinions on roofing issues I ma facing. I think I do understand almost completely deficiency of my attic insulation indicated by freezing of underneath sections of the roof sheeting as well as possible up-slope freezing of water on external shingles. Ice shield should be I understand protecting such condition but it possible it does not do the work per original design. I am stating it due to the fact that more of the water condensation as well as signs of wet spots appear on close to the rafters as well. In addition it appears more active on the north side of the roof.

Well, bottom like is that as one of you mentioned here, we need to go back to the original roofer and complain as required. Since the north side of the roof is showing wet spots I will ask to redo completely this side of the roof from scratch. Second, I will address insufficient insulation problem of the attic. I will add R-38 insulation flat down above the ceiling and on the floor of the attic, add foil membrane to provide necessary vapor barrier and we check it again. I will proceed with the plan ASAP, taking in consideration Sibir-like conditions and snow on the roof at present time. INsulation can be added soon and provision of the vapor barrier will take couple of weekends as well. In addition I will add humidistat to the existing 14 inch electric fan and it should dry this attic now as well as keep it dry for the future. If not, I will add additional vents on this side of the roof when the faulty side is being reroofed again.

Once again, thanks you guys for sharing you expertise and help you provided to me over last couple of days.

Thanks very much

Chris D
Chicago, Illinois

not enough ice shield,insulation upside down means someone reinsulated wrong way-usually leave orig.insulation in place w proper vapor barrier facing down,then add unfaced insulation batts of necessary size(you want r-30to r-38)2 layers of faced insulation will create condensation problems,make sure gable vents are closed so cold air doesn`t blow against the heat pipe and create condensation also----rip it all off and start over :wink:

:slight_smile: Your attic situation is more complicated than you think. Your roofer is not to blame, it is an age old problem. First, because there is no passive exhaust (ridge vent) due to the style of your house. Second, the fan should be put on a timer with a thermostat/humidistat override. Humidistats are okay but not in the winter months. The ‘real’ problem is this: ‘Deposition’ is the changing of atmosperic moist air directly to frost (check your dictionary). This is why it snows in the winter and not rain. The attic frost always happens when the ‘dew’ point is just right and on the coldest surfaces (it’s mainly from the outside air coming in).
Because the north side of your house is the cold side, this will happen. Vents or no vents, this condition happens. BUT, the great thing is that the opposite also happens. the frost changes back to vapor ONLY if you have ventilation. Otherwise it goes from frost to liquid and then to vapor. To stop the liquid part of the process you must have ventilation. At that level of dew point/cold, the fan humidistat probably won’t pick up the overall moisture content of the attic and the fan won’t turn on (your attic remains unventilated because as we all know by now, you need INTAKE AND EXHAUST for attics to ventilate!). So set the fan’s timer for early morning continuously to darkness during the winter. This will compliment the summer months since the timer will go off but the thermostat will kick in. You see it is very hot in late afternoon around the same time it gets dark in the winter. Let me know 610-622-4455