Need Some Roofing Advice

[steveh_131]

Hey ever-helpful INGO friends. I've got a few questions that I was hoping some roofing experts could answer for me.

I've got a 60-year old ranch style house with maybe a 10-year old roof. It has a peak vent all along the length of the roof, and periodic soffit vents. There is one brick chimney. I also have a whole-house fan.

I've discussed my moisture issues here before, where I have condensation raining from my living room ceiling in the summer. It was decided that I needed to seal up my whole house fan to prevent that, so I've been working on creating one.
Last winter, I had what I believed were ice dams, which caused water to seep in around my chimney. It was enough to drip from my bathroom ceiling through the drywall. I tuck-pointed the chimney and caulked all the flashing, and this winter seemed better - but my wife did notice a mildew smell coming from the house fan again. I got up there today and it wasn't as damp as last year, but still a little damp.

While up there, I noticed that all of my sheeting in that area of the house appeared to be pretty damp. Even on the side opposite where the chimney exits the roof. The sheeting is wet enough that I can flex it with my hand.

My shingles are all intact, as far as I can tell. They're not even that old. But when I walked up there, I did feel some flexing in the sheeting that worried me.

Let me know what you guys think. Is this stupid house fan introducing a bunch of moisture up there from the nearby shower in the unvented bathroom? Or is my roof leaking? Seems weird that both sides of my roof would leak at the same time unless the peak vent is causing it?

Here's a few pics. Thanks, guys.

 

[GodFearinGunTotin]

Looks like mildew in that area around the chimney. Does the roof deck pitch down towards the chimney? If so, is there a roof cricket there at your chimney? Like this: http://cdn.roof.net/wp-content/uplo...r-Contractors-use-Chimney-Cricket-300x225.jpg

If not, as that rain and snow melt runs down your roof, it has a hard time shedding away from your chimney and no matter how well it's caulked up, it will be prone to leaking.

 

[GodFearinGunTotin]

Also, you said you had ridge vents, at the peak of your roof, is there a gap in your sheathing to allow the air to actually escape the ridge vents? At your soffits, have you made sure, the soffits vents are open to your attic? I had a house one time that had ridge vents and soffit vents but they blocked all the soffits with insulation. And they don't work so well that way.

 

[steveh_131]

Looks like mildew in that area around the chimney.

Yes, I have mildew like that on most of my rafters in that area... not sure what to do about it.

Does the roof deck pitch down towards the chimney? If so, is there a roof cricket there at your chimney?

If not, as that rain and snow melt runs down your roof, it has a hard time shedding away from your chimney and no matter how well it's caulked up, it will be prone to leaking.

Yes it does pitch down and no, there is no roof cricket. Dang.

Also, you said you had ridge vents, at the peak of your roof, is there a gap in your sheathing to allow the air to actually escape the ridge vents? At your soffits, have you made sure, the soffits vents are open to your attic? I had a house one time that had ridge vents and soffit vents but they blocked all the soffits with insulation. And they don't work so well that way.

There is a gap, I can see daylight coming in.

The soffit vents looked clear but I should go check them anyways.

Do you think a lack of ventilation could be causing this moisture (Other than the stuff coming in at the chimney)

 

[Rookie]

I imagine moisture is the problem before venting.

 

[GodFearinGunTotin]

I would think if everything is opened up, unless you've got something dumping a ton of moisture up there, that should be adequate. If you google around, there are specifications for how much ridge vent you need per square foot, etc. You also need x many square feet of soffit vent/foot of ridge vent.

I think you blocked off that attic fan didn't you? During the winter, that would allow warm air to rise up and collect in the attic.

In that house I mentioned above, I added a powered attic vent. I didn't do it to correct a moisture problem but to help cool the attic off so the AC could keep up in the upstairs in the summer. If you determine you have a moisture collection problem, those powered vents aren't hard to put on--especially on what looks to be a relatively low pitched roof like yours.

ETA: If that whole house fan is still there, as that warm air rises up through it, as soon as it hits that cold roof deck, it's going to try to condense.

 

[steveh_131]

The fan is still there - I worked on putting a cover together but it never got done. Life kinda got in the way...

Could that damn thing be the whole problem? I'm removing it once and for all if so.

 

[91FXRS]

The gap on the ridge vent needs to be cut according to roof pitch i do believe.

 

[GodFearinGunTotin]

The fan is still there - I worked on putting a cover together but it never got done. Life kinda got in the way...

Could that damn thing be the whole problem? I'm removing it once and for all if so.

Could be. My brother has one in his house (a ranch with gable ends) and has never had that problem that I know of. But it's the most likely culprit I can come up with.

But that stuff around the chimney looks like a leak to me.

 

[GodFearinGunTotin]

In photo 1, there appears to be a large white spot on the roof deck, on the right side of the photo. That wouldn't happen to be right above the fan, would it?

 

[steveh_131]

The gap on the ridge vent needs to be cut according to roof pitch i do believe.

Are you saying that the gap may not be wide enough?

But that stuff around the chimney looks like a leak to me.

The chimney definitely leaked - which I've largely corrected, but that doesn't explain the wetness on ALL of the sheeting on that side of the house, does it?

In photo 1, there appears to be a large white spot on the roof deck, on the right side of the photo. That wouldn't happen to be right above the fan, would it?

Yes... now that you mention it, yes that's right where the fan is.

Also, only the side of the attic with that fan nearby has the moisture issues. Above the garage is bone dry. And the roof is all the same age and construction.

 

[GodFearinGunTotin]

Are you saying that the gap may not be wide enough?



The chimney definitely leaked - which I've largely corrected, but that doesn't explain the wetness on ALL of the sheeting on that side of the house, does it?



Yes... now that you mention it, yes that's right where the fan is.

Also, only the side of the attic with that fan nearby has the moisture issues. Above the garage is bone dry. And the roof is all the same age and construction.

I think you've got the problem narrowed down.

 

[GodFearinGunTotin]

Are you saying that the gap may not be wide enough?



The chimney definitely leaked - which I've largely corrected, but that doesn't explain the wetness on ALL of the sheeting on that side of the house, does it?

Go to Owens Corning website or somewhere that manufactures ridge vents. They should have a installation manual for download and it will tell you about the requirements.

Yeah, that should not be damp. It could be a very slight leak, like maybe a nail head popped through.

 

[steveh_131]

I think you've got the problem narrowed down.

Alright - so let's say that this was just a condensation issue. Is my sheeting all ruined now and needing to be replaced?

Yeah, that should not be damp. It could be a very slight leak, like maybe a nail head popped through.

I did notice a few nail holes with extra dampness around them. But pretty much all of the sheets, both side of the roof are damp in that area. Seems like it would have to be a roof-wide shingle failure to cause that if it were a leak - unless something was done way wrong during installation.

 

[CHCRandy]

That first photo sure don't show much cut-out for the ridge vent, if any. Ridge vent is about 2000 square foot attic needs about 28' of ridge vent and minimum of 500 Square inches of intake. That ridge has to be cut out a minimum of 1 1/2" down each side from peak with a ridge board, if trusses with no ridge...you can go a little less. You have to have proper measurements on cut-outs or you might as well not even have them.

Maybe post some more photos of your intakes on exterior and pictures of just the ridge peak. I think you have a ventilation problem. I have seen poor ventilation rot plywood away, especially in vaulted or cathedral ceilings that have insulation packed in with no air space.

Good luck. If I was closer I would give you a hand figuring it out.

 

[GodFearinGunTotin]

Alright - so let's say that this was just a condensation issue. Is my sheeting all ruined now and needing to be replaced?

Probably, at some point. It depends on how much rot set in. Now you're near the end of my experience.

I've had a leak that I just never could get stopped so I pulled the shingles up in the area and reflashed it. Some of the OSB was kind of "punky" so I cut it out and replaced it. If you have spots, like near that chimney, it's not that huge of a deal. If I can do it, anybody can.

I did notice a few nail holes with extra dampness around them. But pretty much all of the sheets, both side of the roof are damp in that area. Seems like it would have to be a roof-wide shingle failure to cause that if it were a leak - unless something was done way wrong during installation.

I'd work to get that attic fan blocked off, even if it were just a temporary plastic sheeting over the opening and see how things dry out.

 

[BobDaniels]

you need either ridge vents/roof vents OR a fan, but not both. Soffit vents must be there for either.

ETA: I might have misread. Is this fan a bathroom fan or roof fan?

 

[steveh_131]

That first photo sure don't show much cut-out for the ridge vent, if any. Ridge vent is about 2000 square foot attic needs about 28' of ridge vent and minimum of 500 Square inches of intake. That ridge has to be cut out a minimum of 1 1/2" down each side from peak with a ridge board, if trusses with no ridge...you can go a little less. You have to have proper measurements on cut-outs or you might as well not even have them.

Maybe post some more photos of your intakes on exterior and pictures of just the ridge peak. I think you have a ventilation problem. I have seen poor ventilation rot plywood away, especially in vaulted or cathedral ceilings that have insulation packed in with no air space.

Ok, I'll get up there asap and figure out what I've got for a peak vent and measure the openings. And I'll double check the soffit vents.

Probably, at some point. It depends on how much rot set in. Now you're near the end of my experience.

I've had a leak that I just never could get stopped so I pulled the shingles up in the area and reflashed it. Some of the OSB was kind of "punky" so I cut it out and replaced it. If you have spots, like near that chimney, it's not that huge of a deal. If I can do it, anybody can.

I'd work to get that attic fan blocked off, even if it were just a temporary plastic sheeting over the opening and see how things dry out.

Ok, I can do that tonight. So you ripped up sheeting yourself and re-shingled? I'm a pretty well accomplished do-it-yourselfer but I'm a little nervous about this.

you need either ridge vents/roof vents OR a fan, but not both. Soffit vents must be there for either.

ETA: I might have misread. Is this fan a bathroom fan or roof fan?

This is a 'whole house fan'. I'm sealing it off tonight with plastic.

 

[GodFearinGunTotin]

Ok, I can do that tonight. So you ripped up sheeting yourself and re-shingled? I'm a pretty well accomplished do-it-yourselfer but I'm a little nervous about this.

Yeah. I did a lot of research, read a bunch of articles, manufacturers' installation guides, etc. and it's really pretty straight forward. The key thing is to never interfere with water's desire to go down hill. Then the other key is to find a stretch of dry weather because no matter how much you educate yourself, you're still doing it for the first time so it's going to take a lot longer time than a professional.

 

[SumtnFancy]

Insulation plays a huge part as well. If you aren't keeping the heat down, it will pass up into the attic and condense on the underside of the roof decking. That combined with a lack of ventilation will cause mold/rot/etc. I see a lot of clever foam board boxes over whole-house vents to cut down on heat transfer into the attic for this reason. Rent a mold fogger with microbium from home depot, fog the attic, spray the entire roof structure with Kilz paint, reinsulate, and add more ventilation. Any of those steps will help, all of them should cure it.