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denske35
Is this Mold on Basement joists?

I am in the process of cleaning up the basement and have found a few joists which have some brown/dark green growth/flaking. It scrapes right off with a wall paper scraper. On the 4 or 5 joists which have this it's only on one side. Initially i though the joists may have been painted before. I really don't see any reason for these joists in particular to have been wet or reason for mold but can't explain what else it might be? Is it safe to continue scraping this off? I am planning to paint the cement walls/floor and overhead joists and floor boards.

Blue RidgeParkway
Re: Is this Mold on Basement joists?

Looks like ...... dirt.

When homes are being built, they'll lay the joists flat, and use them to walk around and lay out the rest - usually tromping back and forth over the dirt/clay outside of the foundation line, maybe enhanced with some portland or mortar mix. Then tilt them on end on the girder and foundation sill line up a rim or band joist and start nailing away. Rarely does anyone go back and wipe off the mud/clay slime and it dries along with the wood continuing to dry. If the basement ceiling is finished no one ever sees it. Your basement appears unfinished...so you do (see it that is).:D

Re: Is this Mold on Basement joists?

It is hard to tell by the picture,it might be dirt as Blue Ridge says, but since the house is an old one (I assume) it might be also mold.There are several species of mold and some do resemble the stuff I see in the pictures.

A few questions:
- Does it smell musty? Does it smell at all? Active mold is usually quite smelly. You can smell it even before it begins to show.

- Does the wood in which you found those spots feels damp? A good idea would be to measure the water amount in that wood.

- Test the safety of the joists by trying to poke a hole in the wood with a pen. Mold usually causes the wood to rot.

And finally...

- Is your basement dry, or does if feel damp, humid? Humidity in the air is absorbed by the wood thus favoring mold growth. Of the humidity levels in your basement are above 50% (which can be easily measured with an inexpensive hygrometer) it might very well be some sort of mold. If that is the case,scraping it off might cause it to release spores in the air and spread all over the basement.

Blue RidgeParkway
Re: Is this Mold on Basement joists?

Something occured to me this evening when I was checking something in the barn. It wouldn't hurt to have this checked under a microscope with special lighting, If you think there's a chance that the joists were once intentionally coated on the exposed sides completely with this substance...don't know the age of your home but see floor above - maybe, just maybe they were once intentionally plastered with a fire retardant - say a short ceiling clearance and a coal furnace used to sit there....wonder if some sort of asbestos could be present - there was a time period where such was plopped just about anywhere. Probably just dirt but for a few dollars you could ship that sample in the photo off and get a look-see.

denske35
Re: Is this Mold on Basement joists?

Thanks for the replies, it's much appreciated. To answer some questions the basement is fairly dry with french drain system and sump pump. I utilize a dehumidifier in the basement that was left by the previous owner (17years). I'm not the original owner (last 5years) so not sure of any preexisting issues; ie. why the french drain was installed, etc.. The joists are not moist nor rotted. Seems we can't find a conclusive answer by just looking at thiese photos so I'd like to send this sample away for testing. Can anyone recommend a place to send the sample for testing of mold/asbestos?

Cheers,

Dennis

denske35
Re: Is this Mold on Basement joists?

Couple more things: it does not smell and I've attached some HD pictures of the sample (front and back of the piece I scraped off).

Blue RidgeParkway
Re: Is this Mold on Basement joists?
denske35 wrote:

Thanks for the replies, it's much appreciated. To answer some questions the basement is fairly dry with french drain system and sump pump. I utilize a dehumidifier in the basement that was left by the previous owner (17years). I'm not the original owner (last 5years) so not sure of any preexisting issues; ie. why the french drain was installed, etc.. The joists are not moist nor rotted. Seems we can't find a conclusive answer by just looking at thiese photos so I'd like to send this sample away for testing. Can anyone recommend a place to send the sample for testing of mold/asbestos?

Cheers,

Dennis

Environmental engineer/testing service/laboratory, look for one via listings with the US EPA and your State's local EPA office.

A. Spruce
Re: Is this Mold on Basement joists?

Looks like simple concrete residue as jkirk suggests, however, for your own piece of mind you should get it tested.

Blue RidgeParkway
Re: Is this Mold on Basement joists?

Portland or mortar mix - yeah like I suggested first post.
Might also be waterproofing materials used on the outside of the foundation walls. No way to tell from here.

Could drop some in water and see what happens - see if its just plain old dirt/clay.

Could drop a bit of it in some acid or drop some acid on it see if its portland mortar/concrete.

Re: Is this Mold on Basement joists?

Finding a mold inspector or environmentalist can be done by going to www.iaqa.org or www.iaqcouncil.org. The IAQA educates professionals and government agencies (among other things) and the AmIAQ Council reviews education and experience, determining whether or not someone is board-awarded as a certified professional in investigation, consultation and remediation. Another resource might be www.aiha.org. I know that some industrial hygienists also help in residential settings and are qualified to do these types of investigations and consultations.

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