My apologies if in the wrong forum.....

Today I noticed a decent amount of mold growing in my attic. It's contained on the plywood underneath the shingles and on the 2x4 trusses contacting the plywood. The majority of the mold is near the soffits. I'd guess maybe 30% of the attic is covered. Does this mold pose a danger to the structural integrity of the 2x4 and to plywood?

Nothing is stored in the attic nor do I go up there often. I'm taking steps to reduce moisture infiltration. However, I'm trying to gauge if professional abatement is really necessary if structurally the roof could be compromised.

 

I don't know if the mold/mildew itself will destroy wood but it can make conditions right for wood decay. How much mold do you have? I don't think I'd be overly concerned with surface mold but if it's thick enough to scrape off, I'd see about removing it....... but I'm not a mold expert - they should be along later

 

The 2x4's have more surface mold then anything. The plywood has semi-scrappable mold, it's not caked on but there are areas where it's sketchy. I also believe this has been preexisting for years as it was prevalent when we bought the house and had it inspected (although the inspector definitely didn't call it mold or make reference to a "mold like" substance).

 

Having the mold abated is one thing, keeping it away is another. How is your soffit and ridge vent situation. The mold is occurring there because the warm air from your house is condensing on the cold surface of the decking. If you had proper ventilation it won't happen. So, I would work on getting it looked into for remediation as well as preclusion. Was it your inspector or an inspector suggested by the Real Estate Agent? Gotta think on that one.

 

I agree with candler! It will come back if u don't fix the cause! Most atick mold jobs are very easy to do! Most for me fall under two grand to do

 

This is the second time this year we have agreed on something What will the others think? Be cool.

 

We must be getting soft in our old age!

 

It was an inspector suggested by the Real Estate Agent, although I was present for the inspection and saw the situation myself first hand.

There's no attic fan, so that's probably 75% of the problem. I'm going to install one in the coming months. The recent ice damming this past winter didn't help either.

Is the moisture due to a lack of attic insulation?

And back to my original question, does this mold pose serious risk to the structural integrity of the roof?

 

Mold in the atic is only caused by a few issues! One roof leaks! Two not enought ventilation which it sounds like u don't have. Three to much humidity from the home. Insulation could help with the ice dams but not the mold! If the issues is not corrected yes it could cause issues with the roof

 

Mold will eat the cellulose fibers in the wood that are binding the wood together.
There's no such thing "mold not being a big deal".
You and hundreds of others on the DIY sites this year are having the same trouble.
That mold is caused by not having enough insulation in the attic, having no, or blocked up soffit vents, no ridge vents, plugged up gutters, no storm and ice shield at the bottom of the roof under the shingles.
There was suppost to be foam baffles installed in the rafter bays so the insulation does not cover up the soffit vents.
Recommended Levels of Insulation : ENERGY STAR
What your stuck with doing now is removing the insulation in that area, putting it and plastic bags and tossing it in the trash. (wear a dust mask when doing this !) Checking out the sheathing and trusses to see if it's shot, if not then treat the sheathing and trusses with boric acid soloution. (any exterminater can do it for you)
Once the weathers warm enough and there's no snow on the roof someone has to remove the first few rows of shingles to check the sheathing and add Storm and Ice shield and also a ridge vent.
A ridge vent, vents the whole roof, not just in a circle like a powered vent. It makes no noise, has no thermistat that's will always fail on the hottest day of the year, needs 0 mainitance. is not unsightly.

 

Wow!! How is not enough insulation a cause of mold? The insulation can't cause are cure mold. Again if insulation is not wet removing it would be a waste. Insulation does not support mold growth

 

Ice Dams : University of Minnesota Extension

And to reply to airmans post, once the insulation gets wet it soaks the paper on it and also the paper on the sheetrock below it, Mold eats starch, starch is in paper.
Once the wood and paper gets wet and mold sets in the mold will keep speading all along the ceiling. Once drywall gets wet it's trash. If the insulation is not removed nothing can dry out and the moisture in the insulation just keeps feeding the mold.

 

Mold needs both food and water without one or the other it dies.
You have mold because you are producing too much water vapor in the home.
Cut down on the water vapor production, deprive the mold of water and it stops growing.
Mostly water vapor is produced by washing and cooking, do you have ventilator/extractor fans in the kitchen and bathroom?
If so, do you use them?
Do you keep the kitchen and bathroom doors closed while cooking and washing?
Some water vapor is produced by breathing and sweating, young children and animals produce a lot of water vapor, because they are so active, old people who sit arround produce less.
Having fish tanks and indoor plants, drying towels and things on radiators also add water vapor to the home.
As you can see, sorting most of these things costs little to nothing, and they can save you a lot of hard work.
Do the easy ones now.

 

Will mold/mildew destroy wood/ degrade structural integrity? = YES
it lives from your wood and mositure together. In order to remove the mold you have to ventilate or make sure that some wet area does not have access to this attic by using for example Styrofoam.