Basements, Attics and Crawl Spaces - Moisture and mold in attic

A week after the flooding in Atlanta, I noticed a chemical or pesticide type smell in the master bathroom. I thought it was just chemicals in the water because of all the run off so I paid it no mind. When it didn't go away or air out, I started to think it might be something else. I didn't notice the smell in the attic, so I didn't think that was the problem. I went back up there today with a flashlight since the smell hasn't abated. I noticed some black mold or mildew and a little rot on a rafter. I don't remember it being there in the inspection 1.5 years ago. Unfortunately, I cannot find the inspection report and do not have access to it online anymore. Could that mold and rot be the cause of the smell? Is there anything I can use to clean it up so it will stop smelling? Is there something I can put on the wood to dry it out and seal it?

I can't explain everything, but any smell in the attic tends to vent to the outside. What area of the house got wet, basement or crawl space, that's where I would look for the source of the smell and any moisture. Did the interior of the house get wet?

Bud

What Bud said...what got wet??? But for the attic problem, a 10:1-water/bleach mix and a graden sprayer will kill the mold. But I doubt that this happened overnight, mold does not grow that quickly. I would suspect you have major air leaks from the house to the attic during the cooler winter months. Such as a bath fan that exhausts into the attic, large gaps in insulation, etc.

mold can grow in less than 24 hours. But if you have rot it has been wet for years.

I agree that you might have to look harder for the source of the odor.

You need to be careful in what you use to deal with mold.
Bleach in the past has been mistakenly recommended as a solution for mold but is no longer.........It will not kill it.
Bleach will discolor it to make it less noticeable and slow down its growth but it will not be eliminated.
Considering household bleach is only 5% sodium hypochlorite, the 95% water remaining will provide the moisture to feed the mold within the porous material.

Mold is everywhere and in the hospital where I work we do our own remediation of small mold areas and bleach has no part in any of it.
Removal is the only positive way to eliminate mold in porous surfaces.
On harder surfaces like wood, scrubbing with soap and water then thoroughly drying if no too badly affected, carefully sanding to good wood or cutting it out are all options.
We then will disinfect the surface with a hospital grade disinfectant but only to slow down regrowth of mold until the wood dries.
So basically removal then drying is the only way to deal with moldy wood.

The hospital grade disinfectant we use is effective against bacteria, anti-biotic resistant bacteria, fungi, yeast spores and mold, but with mold it is only effective on hard non-porous surfaces.

I can't explain everything, but any smell in the attic tends to vent to the outside. What area of the house got wet, basement or crawl space, that's where I would look for the source of the smell and any moisture. Did the interior of the house get wet?

Bud

It's in the attic. I can see daylight at one spot up there that I assume was from a squirrel or something years ago or a problem with the roof. I haven't heard movement in the walls or attic since I moved in. There are a couple of spots that the insulation is disturbed like something nested there, but it could have been that way for a while now.

I have not noticed water inside the house. There is a little brown spot that might be water damage in the bathroom, but that may have been there for a while. There was some discoloration on a rafter that might be above the spot, but it was dry so I'm not sure if it's anything. I'm tempted to drill up through that spot just to see where in the attic it comes out.

The smell in the bathroom is finally dissipating so I'm not sure what to do with it next.

hmhill17...
You failed to mention if the attic is vented to the outside. I'm not just talking about the common "roof-venting". Does the attic have gables at either one or both ends?. You may consider adding a "gable vent" and use a temporary powered vent fan to not only extract residual moisture but as a supplement for air movement. Mold generally does not probagate where there is dryer air movement. As was mentioned a light household bleach/water solution applied to the affected area may neutralize the mold spores. It is best to remember to wear a dust mask over both nose and mouth to prevent inhalation of any spores loosened by the applicating sprayer. The spores could cause respiratory problems. Heating is not necessary as just the air movement will dry the area nicely.

If the smell is like opening a box of old books, that's rot or mold. If the bathroom smell is arcid like a bad chemical that burns your nose, that's the Public Utilities flushing the sewer lines of rodents before they go in. You may have noticed your toilet water bubbling previous to the smell. If that smell is in attic, you may have a vent pipe ajar from another giving you the smell. If comfortable on the roof, smell at the bathroom vent pipe for that arcid smell, or just wait a few days. Ours lasts for three days, before it disipates.
Be safe, Gary