Thread: OSB issue in crawlspace

I'm a relatively new inspector...so would really like your thoughts on the attached photos.

THis was in a crawlspace...obviously moist, lots of minor plumbing leaks, not enough ventilation for sure. My question is, do you think this is mold? or is it more of a delamination failure? I'm not used to seeing that dark color on OSB. I realize that significant work is needed in the floor structure of this house...but I'm trying to understand the MODE of failure to advance my own technical knowledge.

I have included a few other photos to give you an idea of the overall crawl condition...but my main confusion is that first photo.

Thanks,

Dave

IMG_0194.JPG

IMG_0193.JPG

IMG_0196.JPG

IMG_0198.JPG

Similar Threads:

• Back to the collar tie issue...
• Ground in crawlspace
• Holding up the crawlspace walls
• Crawlspace vent fan
• PVC water supply lines in crawlspace

Mould.

The crawl space has had a moisture problem that has created the fungal growth on the subfloor and joists. Also, to be on the safe side, do not call it mold until it has been laboratory tested.

Hi Eric,

Okay... I am going to ask a stupid question.... why would you have it tested?

In my opinion there is a water problem, osb delimitation/weakened, a cellulose based food source which mould is going to thrive on and active leaks.

In any event the OSB judging by the photos will likely have to be replaced anyway, correct the leaks, moisture sources, thus my question to you above, why have it tested?

Cheers,

Where is the insulation?
Removed because it was soaking wet?
My opinion FWIW, this is more of a ventilation issue than plumbing leaks.

If the subfloor is Advantech (and not just OSB) it takes a lot of exposure to moisture for it to delaminate.

Yow!!!

I agree with Raymond here. But I do tell people if they want to make it a negotiable item from the inspection, they may have to play the game and get a mold test done for the sake of proving that the green/yellow/white/black fuzzy growth which everybody knows is mold actually is mold.

For most crawlspaces anymore, I recommend sealing all vent to the exterior and treating the crawl as a conditioned space assuming it has a concrete floor. Summers around here get very humid and open vents on crawlspace walls will allow more moisture and humidity in than they will let out. Put a dehumidifier in the crawl hooked up to a drain line or condensate pump and let it run. Crawlspaces suck!

Originally Posted by Raymond Wand

In any event the OSB judging by the photos will likely have to be replaced anyway, correct the leaks, moisture sources, thus my question to you above, why have it tested?

If one wanted to be sure of being right about some substance being mold then it would need to be tested. In Dave's pictures I'd say that it's "probably" mold. If you're ever in a courtroom and someone asks you why you said it was mold you had better have a lab report handy to back you up otherwise your chances of walking out unscathed will be nil.

Now, that being said, I'd make the ASSumption, without testing, that whatever it is you probably don't want it and therefore it should be removed.

It is definitely moisture damage and it 'appears to be mold", how's that?

I suspect there have been major leaks.

It is freaking mold/mould no need to test it! Dry up the area, clean up the mold and put down a vapor barrier..

Testing will not tell you anything other than it is mold. It is just an unnecessary cost that could be eliminated with common sense.

If it looks like mold, smells like mold then guess what? It is mold! Get some stones and call out the obvious. If you have been at the inspecting gig for very long you know when you find mold or if it is soot, grease or whatever. This ain't rocket science... We can't go through life worrying about the courtroom, do a good job report what you see and go on with life. I have been calling it mold from my start in this profession back in the mid 1990's and have never had anyone question it.

This is from a POS house yesterday, what do you think I called this!

Originally Posted by Scott Patterson

Dry up the area, clean up the mold and put down a vapor barrier.

That's a simplistic description of clean up. Measures need to be taken to not contaminate other areas of the building i.e. containment barriers and negative pressurization. Then there is sanitation and sealing of the affected surfaces along with HEPA vacuuming and air scrubbing. Also consider the possible need for a water management system to be installed to help control moisture issues. In the remediation plans that I have written the HVAC systems have been frequently included in the cleaning / sanitation work.

There are standards for such measures so I'd be hesitant to give the impression that corrective measures are not too involved. Also remember that IAQ conditions affect people's health and there are few situations that can be more costly to H.I.s if information provided to clients is mis-guided.

I know some HIs think it is legally safer to call it a "mold-like substance." I've never been challenged calling mold-like substances "mold" but write it up both ways depending on what I think I am looking at.

Litigants only call it Mould/Mold.

Originally Posted by Raymond Wand

Litigants only call it Mould/Mold.

Most of the time they add "Toxic" to the mix!

good call on the remedy Nick -- building science has shown ventilating crawl spaces does not prevent moisture in most climates.

Seal them up, lay poly on the ground if it is dirt, insulate the walls and treat it like conditioned space.

Dave, The following link contains very good information on crawlspace design and moisture problems: BSI-009: New Light In Crawlspaces — Building Science Information

I must say I agree with Eric, you as a home inspector need to address the issue with your client as to what you have observed. But remember not all mold is black mold or contaminate mold and that is why a test is recommended. Weather the OSB board is in need of replacement that should be determined by probing the wood to see how much deterioration has occured due to plumbing leakage or moisture damage.
Our profession as home inspectors do not alway require the necessary repair or fix and should be referred to a professional contractor to determine the cost and proper fix.
I know how I would repair or address the repair but again in our legal system it is always best to referr a professional contractor for cost purposes and proper repair to prevent any further moisture build up.

Originally Posted by Dave Rose

I'm a relatively new inspector...so would really like your thoughts on the attached photos.

THis was in a crawlspace...obviously moist, lots of minor plumbing leaks, not enough ventilation for sure. My question is, do you think this is mold? or is it more of a delamination failure? I'm not used to seeing that dark color on OSB. I realize that significant work is needed in the floor structure of this house...but I'm trying to understand the MODE of failure to advance my own technical knowledge.

I have included a few other photos to give you an idea of the overall crawl condition...but my main confusion is that first photo.

Thanks,

Dave

IMG_0194.JPG

IMG_0193.JPG

IMG_0196.JPG

IMG_0198.JPG

Hi Dave

Prior to becoming a home inspector I was in the mold remediation and disaster restoration industry for over 30 years
You should use the term or a term like to "apparent mold growth" if you do not have a significant background dealing with mold.
There are many reasons this can be happening. I don't really understand why some home inspectors want to go into in depth explanations about possible causes with the buyer. Our job is to flag conditions during and recommend a specialist for further investigation and advice where required. This is a condition where that should be recommended. Even enclosed modern crawlspaces need a humidity management system of some type. In my opinion OSB is the crappiest building material used, and especially susceptible to mold growth in humid or moist conditions. I for one can tell you that what you are looking at is indeed mold and can potentially affect the air quality to the living space above.
Did you check the box/trimmer joists and floor joists for rot at the crawlspace perimeter? There appears to be some staining to these areas as well
These types of conditions when found are usually a deal breaker

I hope this helps

A dirt crawlspace is a large evaporation field. Just like hot goes to cold, high moisture goes to low moisture. The moisture will be pulled from ground and from wherever the higher moisture is located. This means it will pull it from outside the foundation if it is wetter there. Basically there is an endless supply of moisture in a dirt crawlspace.

In the winter heat radiating down from the house can aid in the evaporation. It also becomes an energy penalty.


The best solution is pouring a rat slab or install a plastic vapor barrier that is well sealed. Also insulate the walls.

Not a home inspector, but: by technical definition, any fungus that forms filaments is a mold. If it is fungus and fuzzy, it's a mold. Not necessarily a toxic mold, mind you, but a mold.
By dictionary (non-technical) definition, any fungus that causes decay can be called a mold.

I think you are safe in saying mold is present. I doubt anyone would argue there were no fungi present in the damp wood. Unless the wood was pasteurized and subsequently kept in a sterile environment, this is a virtual impossibility. They may say the fungi are nontoxic, but then you did not say they were.

I'm waiting for Caoimhn to jump in here. You there Caoimhn?

Thanks everyone for the input. I wrote it up as best as I could, and we'll see what they decide.

Dave

Originally Posted by gary carroll

Not a home inspector, but: by technical definition, any fungus that forms filaments is a mold. If it is fungus and fuzzy, it's a mold. Not necessarily a toxic mold, mind you, but a mold.
By dictionary (non-technical) definition, any fungus that causes decay can be called a mold.

I think you are safe in saying mold is present. I doubt anyone would argue there were no fungi present in the damp wood. Unless the wood was pasteurized and subsequently kept in a sterile environment, this is a virtual impossibility. They may say the fungi are nontoxic, but then you did not say they were.

I see exactly where you're going with that Gary, and I agree. People tend to think that mold is always dangerous...when in reality it depends on the type of mold...which can only be determind by a lab.

Mould dependent on type may only be a concern to those who have lowered immune systems. A lab cannot determine if someone is or will exhibit symptoms to mould.

Only a doctor can determine through appropriate testing if someone is in fact allergic to mould.

Legally inspectors will be on the line for not calling out conditions which create mould or is mould. I have yet to see anyone sued for calling out mould, mould like substance.

Lets not be politically correct about calling a spade a spade please.

Originally Posted by Dave Rose

I see exactly where you're going with that Gary, and I agree. People tend to think that mold is always dangerous...when in reality it depends on the type of mold...which can only be determind by a lab.

While not all molds are toxic, some people have allergies to mold which is a separate issue. CYA requires noting its presence. We aren't expected to identify the type or toxicity.

Mould is bad because it grows on wet wood and keeps it wet. Wet wood is bad because it looses its strength. This is especially true for OSB. Mould growing in OSB can never be completely removed. It will reappear when moisture from the surrounding air allows it to grow again. That subfloor is toast.