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Nospammer 03-01-2012 07:27 PM

is my sheathing rotting? *pics*
4 Attachment(s)
I'm in the pacific NW so it's really wet here but I don't know what to expect in terms of how wet the sheathing should be but I did discover mold along exterior walls in bedrooms when moving some boxes. I washed the walls with bleach, moved the boxes away from the exterior walls & opened windows/ circulated air with fans.
Next, I did an attic inspection for moisture and mold 2 weeks ago and found moisture & mold in attic sheathing and on mold on rafters.
I discovered the bathroom exhaust duct was not vented through the roof.
It stopped short a few inches from a screened vent. It seemed to explain the excess moisture in that part of the attic.
I Installed a proper duct with it's own termination cap through the roof. I gave it a week to see if humidity would go down but it stayed a steady 78% so I Installed an additional roof vent to create more ventilation to help dry out the attic. I noticed exposed staples on the roof so I covered them with roof cement yesterday in hopes that it would prevent water from getting in.

While starting to clean mold in the attic today, I noticed the mold was extensive. Some of the sheathing is starting to dry but I have some concerns...
1. on the sheathing that's starting to dry, the outer layer looks and feels brittle (is this dry rot?)
2. some of the sheathing isn't flush with each piece (buckling from getting wet then dry?)
3. some rafters look like they have signs of dry rot

Upon my examination of the attic I'm wondering if the roof (sheathing&rafters) need to be replaced but I need advice on how bad or not the condition of the roof is as this is all new to me. I don't want to fall thru the roof when I go up there to clean the chimney & I don't want it to leak and contaminate the home with mold.

Do I need to any or all of these:
1. replace potentially dry rotting sheathing
2. "sister" dry rotting rafters
3. dispose of cellulose insulation because of mold

The insulation is not wet but I think some of it may have mold on it.
The home was built in the 80's and from my reading I discovered that plywood made today is of a lesser quality so mold would eat through the new plywood very quickly if it were to return.

Your advice is much appreciated. Please "dumb down" your responses as I am a novice to home repairs & terminology.


OldNBroken 03-01-2012 08:04 PM

From those pictures, yes you do have serious issues that need serious attention. Much of that sheeting looks like it has lost all structural integrity. That must have been ongoing since the house was built.

Dunno about the insulation but if it looks bad it is one of your easiest and least expensive elements there to remedy. That all looks like more than just a bathroom vent issue.

chb70 03-01-2012 08:23 PM


Do I need to any or all of these:
1. replace potentially dry rotting sheathing
2. "sister" dry rotting rafters
3. dispose of cellulose insulation because of mold

You seem to have spotted all the damage correctly, definitely fix
#1 and #2 and # 3 just pull out insulation in that area and replace.

Complete Roof
Can You Dig It !

ben's plumbing 03-01-2012 08:33 PM

yes you have a serious problem ..its rotting..address it now:yes:

ptraz 03-01-2012 08:55 PM

You definitly need to replace whatever wood is damaged and the insulation, however if you don't fix your moisture issue you'll have the same problem again. Your bathroom vent was probably not the problem but it didn't help matters any. You said you added a roof vent. How many do you have, and more importantly do you have vented soffits. You need good airflow through the attic to keep the moisture down and to not grow mold. If you have vented soffits check that they aren't blocked with insulation. If you don't have them you'll need to do more than just have a roof vent.

Gary in WA 03-01-2012 10:57 PM

You have a serious water issue. The mold near the fan is localized, the ridge wet could be condensation OR roofing missing. You should not be able to see "staples" showing, that usually is shingles missing as they are overlapped with the next course- covering the fasteners completely.

An outside picture would help, about 6' away---- only if you are comfortable up there!

P.S. need more inside pics as well...

Tom Struble 03-01-2012 11:32 PM

is this a modular or factory built home ?

Windows on Wash 03-02-2012 06:27 AM


You have some issues there. More pictures would be helpful as well as pictures of where the mold is concentrated.

You have had a system moisture, either bulk or humidity, issue that was not handled by the roof or the ventilation.

Those all need to be addressed in conjunction with the re-framing of that roof and the re-sheeting of that roof.

I would not sister lumber to those failed trusses. Re-build them.

Nospammer 03-02-2012 11:11 AM

Thanks for your replies. What a headache. It's a stick built home. I have 4 roof vents and there are soffit vents on both sides of the attic. There's mold on almost every rafter...harder to tell how much is on the sheathing but it's extensive. Most of the insulation feels/looks dry but hard to tell how much mold is on it.
I'll post more pics soon.

joecaption 03-02-2012 11:20 AM

Some of the roof it's self would be nice.

Nospammer 03-03-2012 04:37 PM

roof pics
6 Attachment(s)
Here are the roof pics.

Nospammer 03-03-2012 04:41 PM

roof pics 2
3 Attachment(s)
...and a couple more roof pics

dougger222 03-03-2012 05:06 PM

Looks like it could be trapped moisture from inside the attic area. A hot roof could be the cause as well as exhaust vents being dumped into the attic area. If your climate gets below freezing in the Winter this can cause this issue.

Houses with these problems I most often see the most rot on the upper part of the roof structure. By the looks of it in your pics I see even trusses that show some rot, not good!

Of course an inproperly installed roof system can also cause water to leak in and cause this.

builttolast 03-03-2012 08:29 PM

Others are correct, also - The EXPOSED NAILS ON THE VENT BOOTS AND TIE-BACKS on the stack NEED TO BE SEALED (caulked over with roofing caulk so seal out moisture/water) ALSO, it is NOT a good idea to run a nail through a shingle when it is exposed to the weather as water can get into it ESPECIALLY as the nail rusts.

framer52 03-03-2012 08:39 PM

your roof is shot.

you do not have enough vents.

You need to remove all of the plywood,some of the trusses need attention and you need new shingles with a ridge vent. On to of that, most likely you do not have enough soffit venting.

I would suggest you do something in the near future.

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