Roof question

[mashburn]

I did an inspection of a 2/12 roof today with my thermal camera and moisture meters. The current owner found 4 leaks, and I found 6 or so places of water intrusion.
The roof coverings are owens corning 50 yr with Sure-nail. They put ice guard on entire roof surface before shingle installation according to manufacturers installation. Entire roof replaced in Sept 07. Previous roof was old 3-tab that never leaked.

The problem appears to be the water is going under the shingles, due to low slope, and running into nail space to drain onto sheathing.

Has anyone seen this issue before?

[Kenton H. Shepard, CMI]

A leak in a low-slope roof? Yes. Nails punch holes in Ice and Weather Shield, nails expand and contract until the gap around the nail is big enough to admit water. There's your leak.

[mashburn]

I just thought maybe there was some other explanation other than nail expansion.

thank you Kenton

[Roy D. Cooke, Sr]

Originally Posted by mashburn

I just thought maybe there was some other explanation other than nail expansion.

thank you Kenton

The nail expansion on Ice and water shied is new to me .
I would have though that there could be some other concern causing this difficulty .
http://www.na.graceconstruction.com/...2693-RCCMC.pdf


...Cookie

[David P. Valley]

Originally Posted by mashburn

The problem appears to be the water is going under the shingles, due to low slope, and running into nail space to drain onto sheathing.

Has anyone seen this issue before?

Michael,

Sounds like ice damming to me. Are you sure that the ice and water shield was installed properly or are you guessing?

[gbeaumont]

Hi to all,

I also very much doubt that the problem is nails through the ice and water shield, especialy on a new roof, the product is designed to have a "memory" so that it closes back around nials and screws, thats the whole point of it.

My guess would be either a very poor installation of the Ice and water layer, or that it is missing in some key areas like flashing locations.

Regards

Gerry

[mashburn]

When I got to the inspection they were removing some of the shingles to replace. The owner showed me the Owens Corning installation instructions that he printed for his roofer to install. He made sure that the roofer, his friend, followed his instructions.

The leaks were coming form all over the roof surface not any areas with flashing, only 3 terminations on this affected side of roof. Ice damming has not hapened as we have not had snow yet.

[David P. Valley]

Now you've got me curious.

What was the roofers verdict? Did you speak to him?

[mashburn]

Roofer has no idea. They all like the idea of expanding nails.
I cannot wrap my head around this issue.

[mashburn]

They owner just called and he told me he is going to cover the entire roof with metal standing seam. Quite a $$$. not sure who is going to pay.
I'll update when I get more info.
Thank you all for your help.

[Christopher Currins]

Was this applied over the old 3-tab or was it a tear-off?
Also, is there any ventilation under the roof deck?

[ckratzer]

It is risky to put shingles on any pitch under 4/12.

A roll roofing product would have been a better choice to prevent leaks.

[Doug Edwards]

What he just said. Ive always heard and have read on bundles anything less than a 3 on 12 pitch is not recommended using shingles. I have seen a bunch of them too and they almost always leaked.

[whandley]

Originally Posted by mashburn

Roofer has no idea. They all like the idea of expanding nails.
I cannot wrap my head around this issue.

Now that is interesting. A licensed roofer with no idea where the leaks are originating? Time to get another roofer, maybe one who is not a personal friend of the owner.

Two more questions? Is the current roofing contractor licensed in that field of expertise? Was a permit pulled and finaled on the existing comp shingle roofing system?

Somethings not kosher when the homeowner has to provide roof installation instructions to the roofing contractor.

[mashburn]

It was a tear off.
Ventilation was supplied by ridge/soffit vents & small gabels.

In my county PA requires no licensing for contracting. Even though a barber and nail manicurist need a license if you can believe that.