Mold in attic

I live in Iowa. Have an attic space above the second story of my home which we use for storage. Noticed mold forming and moisture on the underside of the roof decking. Looking for a couple of ideas -

- What are the most likely potential causes of this happening. the attic has been used for this for at least 15 years and have not noticed this before. None of the wood looks rotted at all. If anything we have reduced the amount of items in the attic recently which would have increase the air circulation.

- Next, what is the best way of getting rid of the mold? As stated above it is not in-bedded in the wood yet and I am not able to find any week spots yet. It is only on the service as i can wipe it off with a finger, at the least what I can see.

Any ideas and direction are greatly appreciated.

Thank you in advance for your ideas.

Saurd

 

Excessive leakage from warm humid air in the house up to the attic. Not enough air circulation in the attic itself. Do you have any type of air vents in the attic ? Like a ridge vent, gable vent or under eave vents ?

 

Hi Saurd. Sounds like something changed. In addition to Pj's questions, are there any exhaust vents dumping air into the attic or ducts passing through. If any pass through double check them to be sure all connections are secure and sealed. And of course if any ducts are dumping air like bath or kitchen fans, they need to be directed to outside.

Pictures always help and don't let this go too long as that mold can become a big issue.

Bud

 

Yes there is a bathroom venting directly into the attic which has increased in usage recently, that is the path I was on as well, just wanted to assure I was thinking on the right track. We do have roof vents in place. and gable vents under the eaves with protectors in place to assure they don't get plugged by insulation. Are there any issues with installing a dryer style vent directly to the exterior? What is the best hing to use to get rid of the mold?

Thank you for your prompt response.

 

Yes..... definitely discharge the vent outside. A dryer type hood will work.
A bathroom vent carries a lot of moisture that condenses quickly in a cold attic.

 

The vents are the best solution, they make them for wals, like a dryer vent, as well as ones that mount under the eves in a horizontal position.

As the moisture dries up so will the mold!

 

Yes, sounds like that bath vent has become the problem. Discontinue using it for awhile to help dry out the current moisture. Interior humidity is usually low in winter so the extra moisture added to the house may be welcome.

Concrobium Mold Control is often recommended but my experience is it may kill the mold but does not bleach out any discoloration. I usually use a mild solution of bleach but the topic is well covered on the internet. Some don't like bleach.

Most dryer vents are directed directly to the outside, just avoind them being too close to any windows. Others may have better guidance.

Bud

I'm just getting slow in my old age

 

Thank you to all. Am off to Home Depot to get what is needed to install the vent.

Will get it dried out and then attack the mold.

Thanks again.
Saurd