Thanks James,
Tree fungus gives off spores when there’s snow covering, as does fungus growing on wooden structures, or any organic material (moss etc.) on vertical surfaces not subject to snow accumulation.
Collecting it below 40 deg. is as you say going to be problematic, I must admit the thought of the Silica gel freezing got by me. Good call, and thanks for the support.
Doug,
Absolutely agree with the findings in this one (as if I had a choice anyway), and good to know that when we push our samples out to the Labs that the technicians are thus qualified. Thanks for spending the time to pull up the referenced document.
We, as home inspectors, are not assessing the mould, just identifying that visible apparent mould exists contrary to our negative hypotheses.
We should write this up in the report with a caveat that states something like “further laboratory analysis by a qualified mould assessor will provide a report detailing the Genus/Species (depending on whether the sample was for non-viable/viable testing) defining if and what types of mould exist in the locations specified in the report”
Would you not agree?
No
Mold Assessor is the INSPECTOR
It’s Friday and we’ve had three mold reports sent to us this week that home inspectors (also grandfathered mold assessors) did. They are a shame. It’s the old you don’t know what you don’t know. Hundreds, even thousands pretend to be mold inspectors.
I tried to take the day off today, but we have 7 jobs so we are working and next week is booked- just can’t complain but the inspectors are a shame.
Turkey Run at Daytona this weekend for you car buffs out there. 
5,000 cars and 75 degrees with sunshine
There is no ideal weather for mold testing. You’ll never find it.
The outdoor baseline testing is required or suggested by the labs. I would not say they are snake-oil salesmen? These people who work in the labs are the ones who are microbiologist and such!! However I will admit and outdoor sample may be false if taken close to the flower bed full of wood chips for instance. I have been around these wood chips and could smell the mold on them
So, I’m still confused as to a consensus on the rain question. iAC2 rules state:
“5.5.3.2 No Rain
– Air pump sampling should not take place outdoors if it is raining. If possible, you should wait for at least two (2) hours after the rain has stopped before taking an air pump sample. Alterations or adjustments to the normal procedure or locations of taking air pump samples, particularly for the control sample, must be recorded in a Chain-of-Custody.” https://iac2.org/sop
Should we be following that advice?
This is corrrect.
Amen Nick!!!
After heavy rains there are excess spores flying around from being dispersed from the trees, structures, etc.
I wait at least a few hours for things to naturally settle. If not there is a good chance you may get a false negative.
Also do not collect the outside baseline (as I just heard of) on the back porch. If there are screens that is not natural (organic dust/debris).
If there is a pool the chlorinated water vapors may cause a false positive.
This has seriously been an eye opening read for a new inspector. Allthough the tone has some negativity at points, this thread really lets one into the mentality of a home inspector. Thanks to all.
I really want to see the video throwdown with Nick and Dr. Co…(cant remember). There would definitely need to be a third guest home inspector/IAC2 to make it interesting. How can we make this happen?
For a minute I was going back and forth, but ultimately believe in what we do. I would also like to learn more after reading this thread, ove taken all of Internachi’s mold related/building science courses, but wolant more, does anyone have any suggestions?
Im in the PNW where it rains for 9 mos a year. There is not a way around it. IH’s and HI’s should be on the same team trying to help eachother not berate them with “nonsensical” mambo jambo. It would be great to turn this thread back around and have some good knowledgeable chat about mold and rain and when and when not to test. Many variables exist and I want to know about them.
Ive got a mold inspection today and its raining outside. Its been raining since 4pm yesterday and will continue to rain late into the night, scratch that, forecast is rain for 7 days… With my current knowledge, I will be taking an outdoor air sample in the garage, or under cover, and setting the timer for a lesser amount.
Does anybody have anything else to share about this topic?
Maybe the IH could chime in with something helpful(not that i didnt learn a great deal from your posts), instead of shame?
First time poster, happy to be a part of the Nachi family.
Thanks for all the learning material and knowledge.
John
Welcome to our forum, John!..enjoy participating. 
Hi John, I do not do mold testing. So this is more of an exploratory question.
I skimmed thru the thread and I read in a few places where testing during rain is a no no. Which makes me think about standards of practice. Is there a standard or practice that you follow and possibly part of your agreement? If so, does the SOP cover precipitation?
Also, are there other ways to test besides air sampling that could serve the customer?
Incorrect the garage does not represent exterior conditions.
Under cover? If it is raining or just stopped the exterior sample will inaccurate.
Notice that the SOP is well populated with “should…” and “if possible…”. Sometimes there is just not much one can do. The client wants the tests done, and trying to plan for the perfect day is not feasible in most cases (at least in my area). So you do the best you can to mitigate the conditions and explain to the client how the results may be affected.
For example; I did one in 20 degree F. weather a while back. I kept the outdoor sample warm until the last moment before placing it on the pump. I increased the run time of the test knowing that the cassette would not be as sticky as it would be in warmer temps. I noted the adverse conditions and mitigation measures on the COC. Finally, I communicated with my client that the baseline sample may not be as accurate as otherwise possible due to weather conditions.
I get it now. The OP is stuck in those conditions up in the PNW. He may never get reliable conditions.
So what about surface only testing? I guess you would have to be able to see the mold for that.
look for the yellow snow
