Was Digest 2h. Re: Washing crawl spaces - now Sanding

[Guest guest]

Ken:

You said:

" Be careful when dealing with Poria Incrassata. This is NOT mold but is a

fungus. "

RESPONSE:

Poria increasata and

Serpula lacrymans

Are a) molds and have more naked eye manifestations.

Unless you can show me that they do not, please define mold.

As for the rest about being careful, correct.

.......................................................................

" Tony " Havics, CHMM, CIH, PE

pH2, LLC

5250 E US 36, Suite 830

Avon, IN 46123

www.ph2llc.com

off

fax

cell

90% of Risk Management is knowing where to place the decimal point...any

consultant can give you the other 10%(SM)

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[Guest guest]

:

1. You said:

" If the mold you are cleaning up today got there once, it'll get there

again. So extreme cleaning using abrasive methods does not at all assure a

clean future. "

RESPONSE:

Come on , then we shouldn't clean at all. It's a risk aspect, if the

cost-benefit ratio is sufficient, then one would be prudent to do it.

2. You dsaid:

" the macro fungi, Meruliporia incrassata, that is plaguing

California can indeed grow macro structures, rhizomorphs, to find and

transport a water source, but that is not the type of visible mold

contamination that people spec to be sanded away. Indeed, poria can be

controlled in place by drying it, which usually renders it dead. "

So

Q1: How do you know it is not Meruliporia or similar? If you don't then

I suggest that you retract the statement.

Q2: I might disagree with " drying " kills it, unless you define drying.

3. You said:

" MY Response: one can ID moisture in a structural wood component without

sanding the top layer of wood, which is typically limited to only a few

mm's.

Sanding is not needed to discover moisture content in wood. "

RESPONSE:

It is true that not needed to discover SURFACE moisture, but a) presumes

that was done (moisture determination) and I have seen deeper MC after

sanding.

4.You said:

" damage is different than contamination or visible growth.

visible surface growth of water caused molds usually is very thin and

limited to the very top layers, which lends itself to cleaning. "

RESPONSE:

It is different but associated.

I'll disagree on the mold on the surface - it varies in depth. Unless you

have taken cross sections of wood as I have, you would caveat that

statement.

5. You said:

" this is unrelated to water damage related surface mold growth. "

I'll disagree, a) I didn't say surface growth and it is associated and

many times related to mold growth. Please read: Faherty, F., and

G. on: Wood Engineering and Construction Handbook. McGraw

Hill Books, NY, NY. 1989; Panshin, A.J., and Carl de Zeeuw: Textbook of

Wood Technology, 4th Ed. McGraw-Hill, NY, NY. 1980.

Tony

.......................................................................

" Tony " Havics, CHMM, CIH, PE

pH2, LLC

5250 E US 36, Suite 830

Avon, IN 46123

www.ph2llc.com

off

fax

cell

90% of Risk Management is knowing where to place the decimal point...any

consultant can give you the other 10%(SM)

This message is from pH2. This message and any attachments may contain

legally privileged or confidential information, and are intended only for

the individual or entity identified above as the addressee. If you are not

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[Guest guest]

Tony,

it comes down to what is 'surface' and 'how' can you clean it? I am going to postulate that you and I would agree to a similar level of visible cleanliness. Whether we agree on a micro level of cleanliness is dependent on whether you do or do not demand zero-tolerance for spores and structures.

I suggest that good scrubbing (brushes, non-abrasive) sufficiently removes the growth when wood is not damaged, that the wood structure left in place is not structural damage; that any mold fragments left in the grain of the wood are not a health risk nor do they increase risk of re-growth. Surface sampling can show very few spores remain on cleaned surfaces (if it's too many, just clean again); compare to non-growth background surfaces.Re-introducing water to those areas will cause growth as sure as it will in the non-affected areas.

I notice that no one has yet addressed the risk to health from all the abrasive materials created and left behind by the sanding or abrasive methods.

That was my primary argument to avoid using abrasive methods.

I also do not see any discussion of risk assessment of the mold fragments and spores left behind in or on the surface after a thorough cleaning with brushes, surfactants, vacuuming, and good old fashioned elbow grease.

Basically, I want to know what good is abrasive cleaning? What does it really get you? And is that extra effort of removing relatively few mold fragments and spores actually necessary (compared to the initial concentration prior to cleaning)?Get the scoop on last night's hottest shows and the live music scene in your area - Check out TourTracker.com!

[Guest guest]

Poria and Serpula are fungi. They are both Basidiomycota - having basidiospores.The interesting and insidious aspect of these fungi is that they do grow from large, easily seen rhizomorphs - and these fungi can send these rhizomorphs a long distance over dry surface in search of a suitable substrate to "eat".You MUST sever the rhizomorph contact to the soil in order kill these fungi. Otherwise they will continue to invade the wood. Also note that it is completely possible to miss an infestation of these fungi with a moisture meter because they take water OUT of the wood.All of this talk is of course, about DRY ROT. Infestation occurs when the equilibrium moisture content of the lumber is above 20 percent. Below 20 percent lumber is immune to fungal attack. Optimum levels for infestation is 30 to 50% (Coggins, 1980). Temperature is also very important for the growth of dry rotting fungi - optimum at about 22C.There are quite a few dry rot fungi, not just Poria and Serpula. Serpula is rather rare in the US. Others are more common.It is a common misconception that the rhizomorphs can push there way through concrete or other structure. They cannot. They look for cracks in the foundation or other structure.Hope this helps. ------------------------------------------------------------ D. Shane, Ph.D.Vice President of Laboratory Services/Chief Mycologist1675 N. Commerce Pkwy.Weston, FL 33326(work) , ext. 268(fax) (mobile) www.reliablelab.com :1. You said:" If the mold you are cleaning up today got there once, it'll get thereagain. So extreme cleaning using abrasive methods does not at all assure aclean future."RESPONSE:Come on , then we shouldn't clean at all. It's a risk aspect, if thecost-benefit ratio is sufficient, then one would be prudent to do it.2. You dsaid:" the macro fungi, Meruliporia incrassata, that is plaguing California can indeed grow macro structures, rhizomorphs, to find andtransport a water source, but that is not the type of visible moldcontamination that people spec to be sanded away. Indeed, poria can becontrolled in place by drying it, which usually renders it dead."SoQ1: How do you know it is not Meruliporia or similar? If you don't thenI suggest that you retract the statement.Q2: I might disagree with "drying" kills it, unless you define drying.3. You said:" MY Response: one can ID moisture in a structural wood component without sanding the top layer of wood, which is typically limited to only a fewmm's. Sanding is not needed to discover moisture content in wood."RESPONSE:It is true that not needed to discover SURFACE moisture, but a) presumesthat was done (moisture determination) and I have seen deeper MC aftersanding.4.You said:"damage is different than contamination or visible growth. visible surface growth of water caused molds usually is very thin andlimited to the very top layers, which lends itself to cleaning."RESPONSE:It is different but associated.I'll disagree on the mold on the surface - it varies in depth. Unless youhave taken cross sections of wood as I have, you would caveat thatstatement.5. You said:"this is unrelated to water damage related surface mold growth."I'll disagree, a) I didn't say surface growth and it is associated andmany times related to mold growth. Please read: Faherty, F., and G. on: Wood Engineering and Construction Handbook. McGrawHill Books, NY, NY. 1989; Panshin, A.J., and Carl de Zeeuw: Textbook ofWood Technology, 4th Ed. McGraw-Hill, NY, NY. 1980.Tony...................................................................... "Tony" Havics, CHMM, CIH, PEpH2, LLC5250 E US 36, Suite 830Avon, IN 46123www.ph2llc.com off fax cell90% of Risk Management is knowing where to place the decimal point...anyconsultant can give you the other 10%(SM)This message is from pH2. This message and any attachments may containlegally privileged or confidential information, and are intended only forthe individual or entity identified above as the addressee. If you are notthe addressee, or if this message has been addressed to you in error, youare not authorized to read, copy, or distribute this message and anyattachments, and we ask that you please delete this message and attachments(including all copies) and notify the sender by return e-mail or by phone at. Delivery of this message and any attachments to any personother than the intended recipient(s) is not intended in any way to waiveconfidentiality or a privilege. All personal messages express views only ofthe sender, which are not to be attributed to pH2 and may not be copied ordistributed without this statement.