Leaking 1/12 roof replacement, ventilation, and insulation

[0o0o0]

Hey everyone, I'm facing my first roofing issue after ~4 years of home ownership.

The house is a 100 year old craftsman in NJ and the roof itself is less than 10 years old. The 2nd floor started leaking during a recent storm and has since been leaking with any amount of rain. I found a few areas where shingles had delaminated and exposed nail heads, some of which were loose in gaps between sheathing. I had a few contractors come out to look and the general consensus was that the pitch was not steep enough for shingle (<1.5/12). One contractor proposed torch down modified bitumen with a 10 year warranty, while the other suggested EPDM with a 15 year warranty at 3x the price.

While inspecting for leaks in the attic I found some minor mold/mildew in areas which had been wet, but also minor mildew elsewhere. The attic has gable vents with a fan on a manual switch as well as a ridge vent, but the roof has exposed rafter tails with solid blocking in between so there is no soffit ventilation. One roofer recommended capping off the ridge vent and leaving gables while the other recommended opening up the soffits and raising the ridge vent. Soffit/ridge seems pretty standard, but since the rise of the roof is only ~18" total, will it be effective?

Finally, the insulation is double faced and in some areas doubled up, so it's just a pile of vapor barriers trapping moisture in an attic with mediocre ventilation. After I remove and clean all mold/mildew, is there really any disadvantage to using unfaced insulation? I don't ever want to deal with this issue again

Thanks!

 

[user 4883]

IMO, your roofers are correct, the pitch is not high enough for a shingle application and some shingle manufacturers will not warranty their product on such a shallow pitch.
Unfaced insulation is what's supposed to be up there so; No issues there.
With no soffit vents, the ridge vent is pretty much doing nothing.

 

[oldognewtrick]

EPDM is a commercial product and carries no residential warranty. A 2 ply base and a cap sheet modified bitumen or a TPO is what I would suggest using.

 

[0o0o0]

thanks!

I was looking into doing that type of roof on the garage myself, I'll ask if that's something that they can do

For the most part I've been reading that faced insulation with the vapor barrier against ceiling is recommended for this area

I'm going to pull down a few of the vinyl soffit panels under the eaves to see if I can remove the frieze blocks or even just punch a few holes in each with a hole saw; if that's the route I go should I block the gable vents?

 

[user 4883]

thanks!

I was looking into doing that type of roof on the garage myself, I'll ask if that's something that they can do

For the most part I've been reading that faced insulation with the vapor barrier against ceiling is recommended for this area

I'm going to pull down a few of the vinyl soffit panels under the eaves to see if I can remove the frieze blocks or even just punch a few holes in each with a hole saw; if that's the route I go should I block the gable vents?

Yes, the first layer of insulation would be faced with face down and then from there, use only unfaced.
Yes, close off the gables if your going to ventilate the soffits, could put some screen material over the holes to prevent insects.