Mold in Attic?

Hi all -

I've got some mold growing in my attic. As I only have one house and no mold experience, I'm not sure how concerned I should be about this. Anyone have experience with moldy attics? I'd like to know if I should be worried about this.

Thanks!

See photos:
Close-up (see nail for comparison in size): Photo 1
Overview (it looks like it is only growing on the newer wood): Photo 2

 

Your first concern should be identifying the source of the moisture. Second is why it is not being vented out of the attic.
1. Check for bath, kitchen, or dryer fans vented into the attic or possibly disconnected up there somewhere.

2. There should be some form of venting, ie, ridge or gable exit vents and low soffit vents to let air in. There are other methods and options, but describe what you have.

Bud

 

I have two gable vents, and a powered fan venting to the roof.

I found that one of the bathroom powered vents was venting just into the attic. I ran some ductwork to one of the vents to move that moisture outside.

Should I be adding a fan to one of the gable vents? My thought was that adding a fan blowing out of one of the gable vents could augment bringing in fresh air from the other gable vent.

The house is from 1970 and the mold only looks to be on the newly replaced wood.

 

having mold anywhere in the house isn't a good idea. it can cause a lot of health problems. you should identify what's causing it first and go from there. then you should figure out how you're going to get rid of it. take action now before it gets too bad.

 

Hi h4t, you didn't mention any lower venting, like soffits, edge vents or lower mounted roof vents. Without lower openings you will get very little natural vent action. Are you sure there are no vents at the eaves?

While we are discussing venting, the other issue is air and heat leaking from the house to the attic. Easier to add a link for the air sealing, just more insulation for the heat.
http://www.efficiencyvermont.com/ste...ide_062507.pdf

Here is a link on venting. There are additional links noted at the bottom.
BSD-102: Understanding Attic Ventilation — Building Science Information

The bath fan would have been a major contributor, good it is fixed. As for the mold that is up there, there are cleaning solutions to address it, but application may be a challenge. Perhaps some of the pros on the forum will pick it up with remediation advice.

Bud

 

I would say a bath fan venting into the attic is likely the source of your problem. It would be better if you installed a rood vent designed for the bath fan ductwork. This will have a damper that closes when it is not running.

 

Thanks for the advice, everyone. How much do I need to be concerned with removing what is up there already?

I don't really know if what I'm showing in the picture is considered "a lot" or "a little" - and how much money I should spend on a pro to get rid of it. (Or even better, attempt myself...)

 

I would not be concerned at all since it is not in the living space. Mold is everywhere outside.
If you want to get rid of it a spray bottle or sprayer with a water/bleach mixture will kill/get rid of it.
Without moisture it will dry up on it own as well.