Condensation

Mark Schniers · 08-15-2009, 05:46 AM

In this photo, you are looking at the underside of the OSB roof sheathing. It appears to have been scorched by fire. Nearest the poorly sized roof vent cutout the OSB has not been affected. Could this be due to condensation?

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**wayne soper** · 08-15-2009, 06:15 AM

yes, The area not affected around the vent is because that area will dry fast. The other areas will stay wet, allow mildew growth and turn black

Mark Schniers · 08-15-2009, 07:40 AM

Originally Posted by wayne soper

yes, The area not affected around the vent is because that area will dry fast. The other areas will stay wet, allow mildew growth and turn black

Thank you for verifying Wayne.

Daniel Leung · 08-15-2009, 07:59 AM

Originally Posted by Mark Schniers

In this photo,....Could this be due to condensation?

It looks different to condensation: no stains on rafters, no stains on OSB around the roof vent (which covered by flashing).
Do you have any more photos on roof and attic? Do you consider it is a leaking from roof?

**Raymond Wand** · 08-15-2009, 08:04 AM

Its certainly not scorched by fire, what is the room below this area? Possibly a bathroom?

Mark Schniers · 08-16-2009, 03:57 AM

Originally Posted by Raymond Wand

Its certainly not scorched by fire, what is the room below this area? Possibly a bathroom?

No bathroom below. The roof did leak in other areas. It was the appearance of the OSB that gave me pause. I had never seen OSB in that condition. FRP plywood I could have made the call.

Ventilation in the attic was poor at best. The 9" roof vent only had a 24 SI hole cut for it. That would hardly carry the air it was intended to carry IF there had been soffit vents.

**wayne soper** · 08-16-2009, 05:12 AM

the condensation occurs when you have warm air leaking into the atic and condensing on the coldest surface which would be the roof underlayment. The rafters would be warmer than the underlayment with snow cover on the roof. The vent has no condensation around it because the warm air pouring out of it keeps that area warm and dry.
I'll bet the attic pull down stairs are very close by and don't seal very well.

Daniel Leung · 08-16-2009, 08:10 AM

Originally Posted by wayne soper

The vent has no condensation around it because the warm air pouring out of it keeps that area warm and dry.

Please see another case that the laundry dryer blows the WARM and WET air into attic. We can see the minor condensation signs around the roof vent and with dripping signs on the rafter.

Terry Neyedli · 08-19-2009, 03:14 PM

Originally Posted by Daniel Leung

Please see another case that the laundry dryer blows the WARM and WET air into attic. We can see the minor condensation signs around the roof vent and with dripping signs on the rafter.

Daniel:
Did you pull back the insulation at the base of the fan duct and notice any condensation/moisture damage there?
By the looks of the rafter it probably is an older structure. There may be more than what meets the eye.

T.Neyedli CHI
BPCPA #47827
www.alphahomeinspections.ca

Mark Schniers · 08-25-2009, 07:18 AM

I have another suspected condensation issue; Based upon the attached photos what are your opinions?

Short of entering the attic and making a conclusion, I'd say the ventilation has become obstructed and is causing excessive condensation which is expressed here by (the appearance of) mold. I have taken swab samples and sent them to the lab.

Notice the rusty metal fasteners.

**Jerry Peck** · 08-25-2009, 07:46 AM

Originally Posted by Mark Schniers

I have another suspected condensation issue; Based upon the attached photos what are your opinions?

Short of entering the attic and making a conclusion, I'd say ...

I'd say ... Why make a conclusion for something you do not know? And why not enter the attic to find out? Or remove the soffit vent if the attic is inaccessible?

I have taken swab samples and sent them to the lab.

Why on earth would you take a mold sample and send that sample to the lab?

That is OUTSIDE the house, there IS MOLD ... OUTSIDE the house ... all around you ... so I'm at a loss as to WHY you would take a mold sample there????

Mark Schniers · 08-25-2009, 09:36 AM

Originally Posted by Jerry Peck

I'd say ... Why make a conclusion for something you do not know? And why not enter the attic to find out? Or remove the soffit vent if the attic is inaccessible?

Why on earth would you take a mold sample and send that sample to the lab?

That is OUTSIDE the house, there IS MOLD ... OUTSIDE the house ... all around you ... so I'm at a loss as to WHY you would take a mold sample there????

Because the client ASKED me to? This was not a full blown HI. Just looking for opinion not attitude.

Anybody else like to share their ideas?

**Jerry Peck** · 08-25-2009, 09:44 AM

Originally Posted by Mark Schniers

Because the client ASKED me to? This was not a full blown HI. Just looking for opinion not attitude.

Mark,

That is not an "attitude", that is my "opinion". And YOU DID ask "what are your opinions?"

In my "OPINION" ... you should have tried to explain the real world mold stuff to your client and how unnecessary that is ...

AND IF YOU DID ... and your client insists on doing the unnecessary, then I guess doing that is no different than working in a donut shop and selling donuts to an overweight person.

Totally unnecessary but their choice.