Delaminated roof decking

Rick Maday · 03-25-2010, 06:54 PM

Why only some sections?

Solutions / Prevention?

Baffles were rectangular cardboard "tubes" about 3" X 5".

TIA

4 year old roof (2nd layer)

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**Brandon Whitmore** · 03-25-2010, 08:57 PM

Looks like you have air sealing/ ventilation issues. I can't explain why it shows up only in patches though.

A.D. Miller · 03-26-2010, 04:08 AM

What rooms were below the areas in question?

Phil Brody · 03-26-2010, 04:26 AM

Lack of attic ventilation. Insulation is preventing airflow. Are the soffits open, ridge vent ?

**Vern Heiler** · 03-26-2010, 04:34 AM

Originally Posted by Rick Maday

Why only some sections?

Solutions / Prevention?

Baffles were rectangular cardboard "tubes" about 3" X 5".

TIA

4 year old roof (2nd layer)

Don't let the 4yr thing blind you. A lot of new (2nd layer) roofs leak! The worst is architectural shingle over 3-tab on a low pitch. Looks like a fairly low pitch from the pic.

Rick Maday · 03-26-2010, 04:42 AM

Originally Posted by A.D. Miller

What rooms were below the areas in question?

Bedrooms

Rick Maday · 03-26-2010, 04:43 AM

Originally Posted by Phil Brody

Lack of attic ventilation. Insulation is preventing airflow. Are the soffits open, ridge vent ?

My thoughts also - soffits blocked - pod vents (no ridge vent).

**Frank Macak** · 03-26-2010, 04:45 AM

If the roof decking is currently wet, roof still leaks or those areas are over the bathrooms. If it is dry, it is probably previous moisture damage, most likely from the first layer of the roofing material. Is there a vapor barrier under the insulation? If there is no vapor barrier and you have poor ventilation, you will see the condensation in specific areas only, especially over the high moisture area. It condensates in the winter, absorbs into OSB when it melts. Delamination, mold is next

Rick Maday · 03-26-2010, 04:45 AM

Originally Posted by Vern Heiler

Don't let the 4yr thing blind you. A lot of new (2nd layer) roofs leak! The worst is architectural shingle over 3-tab on a low pitch. Looks like a fairly low pitch from the pic.

Just added that so you guys would have all the info I have.

Interested to hear more about the scenario you presented - this is exactly the situaton here. Way do you say that, what to you tell clients, what do you recommend.

TIA

**Vern Heiler** · 03-26-2010, 05:03 AM

Originally Posted by Rick Maday

Just added that so you guys would have all the info I have.

Interested to hear more about the scenario you presented - this is exactly the situaton here. Way do you say that, what to you tell clients, what do you recommend.

TIA

The why I say that is from personal experience (the bad kind). I did exactly that, architectural over 3-tab on low pitch. The thicker shingles have more tendency for water to wick-up at the bottom edge plus the triple thickness created at the top of the exposure causes a slight dip where water can almost puddle. The dip doesn't show up until a few years and is not every where. The leaks come at the nails next to the butt joints of the shingles. Might explain why yours jumps rafter bays if the shingles were racked.

What do I tell customers? Well they haven't been as dumb as me so far

.

**Richard DAquanno** · 03-26-2010, 05:08 AM

you can see the insulation is tight up onto the roof, and i dont see any ridge vent panels to keep the insulation down, right now theirs no air flow

not sure of the proper name for those panels

**Brandon Whitmore** · 03-26-2010, 08:32 AM

If it is dry, it is probably previous moisture damage, most likely from the first layer of the roofing material

A good way to find out if it's an on- going issue is to check the nail points that stick through the sheathing. If the nails securing the new layer of shingles down are rusty, you still have an issue. If you can' t find the new nail points, then they didn't use long enough nails and that's another issue.

floyd pfingsten · 03-26-2010, 06:08 PM

It's definitely not the pitch, its at least a 5/12. I would guess a bathroom vent close to the problem area. The roof 2x4's show mold also. Definitely moisture is not being removed. Till the moisture problem can be determined I would recommend installing a small vent in the eave vent to keep the moist air moving out out of the attic space. That is not curing the problem, but the moisture will be removed and stop the mold problem from causing additional problems. Just a thought.

**Jim Hintz** · 03-28-2010, 08:59 PM

Just had one of these myself recently, same scenario - blocked vents, no circulation, quite a few freeze then dry out cycles. The OSB contained Mold and was soft, recommended removal and replacement from the trusses up.