DIY Home Improvement, Remodeling & Repair Forum

DIY Home Improvement, Remodeling & Repair Forum (
-   Insulation and Radiant Barriers (
-   -   Problems with Attic Insulation-Possible Condensation? (

AngelaSteele5 10-14-2012 07:08 PM

Problems with Attic Insulation-Possible Condensation?
Not sure if this question is better suited in this forum, or in the "Walls and Ceilings", but I'd appreciate any feedback. First off, to paint a clear picture of the issue, we live in a regular 1,000 sqft rectangle-shaped brick ranch house. Over a year ago, we noticed some gray-ish places appearing on the outer edges of our ceilings, in every room along the front side of our house, and in one of the rooms on the back side of the house. By outer edge, I mean the side of the ceiling closest to the guttering that runs along the front and back of the house -- just to give you a visual. These gray/shadowy looking places have no particular shape, they vary in size, etc, but just sort of look like gray blobs. We just had a new roof put on 3 years ago, so a leak or some sort of moisture issue from the roof was the last thing we suspected, and we were right. The roof is just fine - no issues there. Then we had a couple of different contractors come out and take a look (wasn't sure what other kind of person you call to come and check out this kind of thing???), and they said that in the attic, directly above the places where we had "shadows" on the ceiling, the insulation (it is blown-in) looked as though it had somehow been moved out of the way or displaced. We have no idea how this could have happened. Anyway, they said that's likely the reason why we are seeing this places on our ceiling - due to lack of insulation in those specific areas. So, we pushed the insulation back into place as best we could, and have tried to wash off the areas in the ceilings as best we can. Some of the gray does come off when scrubbed. We are going to prime it and paint it and hope that it doesn't come back. Our main concern is this: While we were in the middle of trying to figure out what in the world was causing these shadow places on our ceiling, we also did a do it yourself mold test kit in the attic. The test came back positive and mold grew in the petri dish. This is of great concern to us, even though we can find NO visible mold and there is not a musty/moldy smell in the attic. We would like some opinions as to whether or not enough condensation could occur, in an issue such as this with insulation, that would enable mold growth. We cannot understand why the mold test came back positive yet we cannot find any in the attic. There's a vent in the attic on each end, plus an attic fan, so it is very well ventilated. Any thoughts/suggestions, etc., are welcome. Thank you.

nealtw 10-14-2012 09:01 PM

The soffit is the space between the outside wall and the eaves where the gutter is. There should be venting in the soffet area to allow air movement above the insulation to the ridge vent. The outside wall is one of the worst places for heat loss as there is not a lot of room for insulation and air flow. With out air flow the heat will at some time get thru the insulation and warm the roof and that is what causes ice dams on the roof and leaks.
There should be some sort of shoot against the roof sheeting to allow air flow and some bat insulation just above the wall, that stops the wind from entering the attic and moving the loose insulation around.
I hope this helps.

AngelaSteele5 10-15-2012 06:47 PM

Thanks, Nealtw. That is helpful, as we've been trying to determine the best course of action to take to remedy the issue. In the mean time, we are still concerned as to whether this situation is creating a real possibility for mold to grow in the attic. We only plan on staying in this house for 2 more years at the most, and we do not want to run into a situation where there's potential for a mold problem to develop.

nealtw 10-15-2012 07:32 PM

I am no expert on mold but if we add water we often get mold, so my guess is that the spors are everywhere just waiting for the right condition to grow. So I am sure some one could make a test that would always be positive. But that doen't mean you don't have mold, if it is there you do need to deal with it. Perhaps a different brand of test and try it again. If you have had ice dam problems you coul;d have some mold on the drywall where you have stains.
If you have a well placed vapour barrier the ceiling can hold alot of water and for a time will only show up at drywall screws. Perhaps a closer inspection of the area around where the insulation was moved back. If you push back insulation at the center of the house and see what things should look like to compare with.
You would be looking for dirt and ressidue left on the vapour barrier, clumpy insulation and stains on the rafters and ceiling joists.

CRS 01-09-2013 10:20 AM

Mold is everywhere, and if your going to do a "home test" its going to result positive 99% of the time. The grey spots that keep appear can be mold as mold comes in any colour, shape or forms. The best solution to determine if you actually have mold is hiring a professional to do a air test sample. They will conduct one outside as a control and then one in your attic to determine if their is an elevated levels of mold spore

natev 02-08-2013 12:49 AM

Do you have baffles installed in the attic to shield the soffit vents? If not, then you need to get some (they're not expensive)

Just a wild guess...but since we're talking about exterior walls...on a cold day if your house is warm enough & if the insulation had moved so that there wasn't coverage over the areas in question then I guess it's possible that there could actually be enough heat exchange to cause condensation to accumulate...

All times are GMT -6. The time now is 05:09 PM.