[Greenbuilding] Mould Advice

[Stephen Collette]

Hello Irina and everyone,

I'm an Environmental Building Consultant and a Healthy Home Inspector  
(residential air quality) so I will wade into this one.

First all mould is toxic to some degree to some people. Some people  
will die from a glass of wine or some cheese, others can play with  
the stuff. It's all bad. Stachybotrys mould identifies that there has  
been long term wetting in the building material. Sampling helps get a  
better picture from what is going on with the problem by  
understanding what the various types of moulds are present as they  
each have specific needs and requirements for survival. Levels taken  
in the air sample (if taken vs a tape lift) will determine how much  
of a direct exposure is impacting your family's health.

Having the roof fixed is priority one, stopping the source. That is  
taken care of and that is great.

Dead mould is toxic. Period. We are allergic to the mycotoxins in  
mould. That is their little defence mechanisms that they fight each  
other for a prime piece of soggy drywall. They actually duke it out  
and fight each other. Stachybotrys is a heavy hitter as it needs long  
term wetting and so it needs big water and big food to survive, so it  
fights hard, as the others like Aspergillus or Pennicillium need a  
little bit of water, so they appear first.

The idea of using bleach is really old school. We all used to do it  
in the old days, but air sampling techniques and a better  
understanding of the mycological interactions have led us to drop  
that. Bleach is a biological killer. It will kill mould. It will kill  
people (we dropped in on the Germans in WW1 and called it mustard  
gas, now it comes in a 4L bottle with a handle) It's toxic. Don't use  
it at home, don't use it on mould. Mould, from research, has shown  
that it goes into the fight or flight mode when exposed to a threat.  
So it may do one of two things, possibly spore off, or release more  
mycotoxins at you. Well done, you've given yourself a toxic headache  
from the bleach exposure and now released more mould toxins into the  
air. Bravo.

So what do professionals do now? Well they define a scope and scale.  
Is this damage big enough to require an isolation and  
depressurization to prevent the mould from sporing off during the  
deconstruction? If so, that is probably more than you can handle.

If it's not that bad, then still depressurize the space and try to  
contain the space, and wear all your personal protective gear.
Rob Tom made great reference to Canada mortgage and housing corp's  
info on homeowner how to's. I agree

Soap and water is really all you need. Soap breaks the surface  
tension and the water encapsulates the mould. Unscented dishsoap or  
TSP (trisodium phosphate) work great. Essential oil of thyme is a  
good additive as well. It's the main ingredient in Benefact.  
Concrobium (sold at home despots here in Canada) main ingredient is  
TSP.  You could easily make your own using both. (Thyme is slightly  
better than tee tree oil in my experience, but if you have a  
preference, yes tee tree oil works fine) I've used thyme for my MCS  
(multiple chemical sensitive) clients who couldn't use anything else.  
We also used her natural soap on her walls as she couldn't use TSP.

Sanding is almost correct procedure, it's usually  a HEPA vac and a  
wire brush. This pulls the existing mould out of the remaining  
structural members.

Fungicides or biocides can be pretty toxic options. If under  
containment and depressurization, they will off gas. I agree, they  
may take a while or may leach chemicals indefinitely, but that is  
industry standard with insurance jobs I've seen. They put these on to  
cover up any remaining moulds to help ensure nothing will grow again  
in that area. So if that is a concern, then you should cover it with  
something it doesn't like as well.

I would be happy to discuss this further with you, but it would be  
better off the listserve as that is beyond this group's focus.

Mould however is albeit minor, an issue with green building. We all  
work hard in our respective fields to make homes better, and  
healthier for the planet and our family. We try to use our building  
science, our knowledge pool (like this listserve) and any other  
resources we can find. Keeping mould out of green homes is important  
as poor air quality rarely rates high in green building. Ditto for  
rotten construction. Understanding water and it's movement in  
building structures is stunningly simple yet amazingly complex. (My  
solution is to keep houses inside so they don't get rained on, but  
I've yet to find someone willing to go through with that!)   
Protecting the building envelope is something green builder's pride  
themselves in (that and cool new gadgets or ideas) and it's really  
where I marry the two parts of my business. I hope this has been  
helpful.

Stephen

Stephen Collette B.B.E.C
Principal

Your Healthy House
Indoor Environmental Inspections & Building Consulting
www.yourhealthyhouse.ca
stephen at yourhealthyhouse.ca
705.652.5159


>
> Hello green builders,
>
> We discovered significant amount of stachybotrys mold species  
> (along with a
> few other less scarry types of mold) in the wall and the floor. The  
> source
> of moisture (roof) had been fixed a three months ago. I am told  
> that the
> only way to ensure that the mold colony is completely eradicated is to
> remove the wall board, the floor and the sub floor, sand down the  
> rafters,
> and treat the area with a fungicide or biocide. I am concerned with  
> the
> long term off-gassing issues of a fungicide or biocide and would  
> appreciate
> any suggestions for an alternate treatment or thoughts on the off- 
> gassing
> issue.
>
> Thank you very much for the help,
> -------------------------------------------------
> Irina Golfman Rosenblum