Re:TESTING WALL CAVITIES OF HOUSE

[Guest guest]

Hi Barb,

The air is a particular wall cavity can be tested from an electric

outlet (I built a little plastic box that fits over the outlet,

attached to a vacuum), but you don't want to use culturable

(petri-dish) sampling for this since most of the mold spores (if there

was mold growth) are dead. The sampling should be done with a spore

trap (for total spore analysis).

I had problems in my office but only on days when the wind blew from

the northeast. I took an air sample from a gap in the wainscoting

(100+ year-old house) and observed Aspergillus spores covered with

coal soot and no one had burned coal in over 60 years.

There's still time to enter: www.cleansweepcontest.com

May

May Indoor Air Investigations LLC

Tyngsborough, MA

www.mayindoorair.com

978-649-1055

>

> TESTING WALL CAVITIES OF HOUSE

>

> POSTED BY: \ " BARB B W\ " BARB1283@...

> BARB1283

>

> Sat May 1, 2010 7:10 pm (PDT)

>

> I haven't ever brought this up before but can't see what inside walls

> and that is a real worry, but can't a person take the wall sockets off

> walls and put one of those devices that suck air from area into it and

> impact what is ever in air onto a petri dish and test air inside walls

> that way?

>

> I have thought about this for one reason. I think what happened to

> my house is that it is an old house that was built so that air

> completely circulated throughout structure, throughout basement and

> attic and rooms too. It was not intended to have insulation or VENTS

> in roof, so what happens is it was 'updated' to what the new housing

> industry is doing, i.e. person who had house before me added

> insulation in attic and wherever they were able to put it. That cut

> back on air circulating as it was designed to but still much more air

> leakie and much more mixing of air than modern houses are. THEN a

> roofer was here doing work and said " YOU NEED ROOF VENTS " , you don't

> have any vents in your roof. Well, I realize now that he is looking

> for business and is not an architect or builder, so I shouldn't have

> taken his word for it, and added them, sounded as if roof vents would

> help the house to be cooler in summer. In fact I'm such a fan of

> " fresh air " and liked the idea so much, I added more than he

> recommended. He didn't say that was a problem, but later talked to

> someone else that had problem after adding venting and they had added

> more vents than recommended also, so quantity of vents could have

> added to degree of problem.

>

> Anyway, what happened is that outside air was able to come into attic

> and ***get into house interior VIA wall cavities that it was never

> meant to carry outside air!! ...so outside air was able to mingle

> with inside air in the wall cavities of house and over time problem

> developed (with my health) and later realized with the house. In

> addition to maybe growing mold and bacteria, which we were never able

> to locate, but tested in dishes, it dragged into the interior of

> house, dirty insulation from attic which caused my skin to itch

> terribly and I sometimes scratched so much, I scratched open my skin,

> giving me a constant rash (which could have allowed any kind of

> bacteria or mold direct contact with blood).

>

> ANYHOW, I closed up vents, cleaned attic and took out dirty

> insulation. However I don't know if there is any substantial water

> damage inside of walls and if so, where. Has anyone done this, suck

> air out of the walls and onto petri dishes and tested the dishes.

>

> I thought the attic was source but when we got up there to clean up,

> noticed there was no odor at all and professional cleanup service I

> hired saw no water damage, just alot of soot. There was a bird nest

> and dead bird up there and insulation was old and was good to get out

> since air can move down into house. We do have more plans to do some

> 'air sealing' to prevent air from mingling but just closing up the

> vents did alot.

>

> Forgot to add, the outside air coming into house did cause much water

> condensation on windows, so I think that was evidence of condensation

> occuring with outside dry cold air and indoor warm moist air in the

> winter. It didn't condense in the attic apparently, so I'm thinking

> condensation may have occured inside the walls. Any thoughts on this

> mode of testing?

>

[Guest guest]

Thanks Jeff!

I noticed on your site, you say to keep 'high pollen producing plants away from

doors and windows'. Are those flowering plants and trees?

>

> Hi Barb,

>

> The air is a particular wall cavity can be tested from an electric

> outlet (I built a little plastic box that fits over the outlet,

> attached to a vacuum), but you don't want to use culturable

> (petri-dish) sampling for this since most of the mold spores (if there

> was mold growth) are dead. The sampling should be done with a spore

> trap (for total spore analysis).

>

[Guest guest]

Hi Jeff,

I seem to get a lot of insulation fibers in my wall cavity samples, and get a

lot of negative results in situations where subsequent opening reveals a lot of

mold. Any suggestions?

Connie Morbach

>

> Hi Barb,

>

> The air is a particular wall cavity can be tested from an electric

> outlet (I built a little plastic box that fits over the outlet,

> attached to a vacuum), but you don't want to use culturable

> (petri-dish) sampling for this since most of the mold spores (if there

> was mold growth) are dead. The sampling should be done with a spore

> trap (for total spore analysis).

>

>

[Guest guest]

Connie,

If there is insulation inside the walls then I expect three things:

1. Some of the insulation will be sucked into the cassette.

2. The quantities of spores reported per cubic meter are not

valid. At 15 L per minute you need a minimum of 15 Liters of air

inside the wall. If you sample for 5 minutes you need an air space

of 75 L, assuming you get all of it out without pulling in air from

the room. Then you get a combination of room and wall results,

not just the wall.

3. Results will be based on only the tiny location at the point of

the sample, not representative of the entire space between studs,

let alone the entire wall. For example, and just the opposite of

what you sited, a recent sample from an outlet returned high

enough levels to warrant further investigation. Opening the wall

revealed tightly pack cellulose showing no signs of dampness or

mold growth - except for the area right at the outlet where the

sample was collected. Results were " accurate " for that spot but

not representative of the wall.

I don't put much faith in wall samples except for answering a very

specific and relevant question which cannot be answered by

other means. Even then only qualitatively, not quantitatively.

Carl Grimes

Healthy Habitats LLC

-----

Hi Jeff,

I seem to get a lot of insulation fibers in my wall cavity samples, and get a

lot of negative results in situations where subsequent opening reveals a lot of

mold. Any suggestions?

Connie Morbach

>

> Hi Barb,

>

> The air is a particular wall cavity can be tested from an electric

> outlet (I built a little plastic box that fits over the outlet,

> attached to a vacuum), but you don't want to use culturable

> (petri-dish) sampling for this since most of the mold spores (if there

> was mold growth) are dead. The sampling should be done with a spore

> trap (for total spore analysis).

>

>

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[Guest guest]

Thanks Carl,

I have not collected many wall samples, based on negative results and lots of

insulation. The negative sample I mentioned was collected in a stud bay two

spaces away from an area of significatn growth. Unfortunately, it seems that

opening an area under controlled conditions is the best way to evaluate a

suspect wall cavitity.

Connie

>

> Connie,

>

> If there is insulation inside the walls then I expect three things:

>

> 1. Some of the insulation will be sucked into the cassette.

>

> 2. The quantities of spores reported per cubic meter are not

> valid. At 15 L per minute you need a minimum of 15 Liters of air

> inside the wall. If you sample for 5 minutes you need an air space

> of 75 L, assuming you get all of it out without pulling in air from

> the room. Then you get a combination of room and wall results,

> not just the wall.

>

[Guest guest]

Connie and Carl,

I would agree with you about testing wall cavities. The results are

definitely very qualitative and often not meaningful.

If the wall is full of insulation, the fibers filter everything from

the air flow, and unless the problem is at the outlet, you will not

see any evidence for mold growth even if it is in the cavity.

On the other hand, if the wall cavity is not insulated, you have a

chance of seeing something if you:

1. first suck all the loose junk out of the outlet box and then

2. gently bang the wall to loosen some spores during sampling.

But the absence of mold spores does not mean that the cavity is mold-free.

If I see spore chains or clusters, this is definitely indicative of

mold growth (but unfortunately, no labs report on the presence of

chains!).

May

May Indoor Air Investigations LLC

Tyngsborough, MA

www.mayindoorair.com

978-649-1055

2b.

> TESTING WALL CAVITIES OF HOUSE

>

>>

>> Hi Barb,

>>

>> The air is a particular wall cavity can be tested from an electric

>

>> outlet (I built a little plastic box that fits over the outlet,

>> attached to a vacuum), but you don't want to use culturable

>> (petri-dish) sampling for this since most of the mold spores (if

> there

>> was mold growth) are dead. The sampling should be done with a spore

>

>> trap (for total spore analysis).

>>

>

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> Messages in this topic [37] (4) 2c.

>

> TESTING WALL CAVITIES OF HOUSE

>

> POSTED BY: \ " CONNIE\ " CONNIE@...

> CONNIEMORBACH

>

> Sun May 2, 2010 6:41 pm (PDT)

>

> Hi Jeff,

> I seem to get a lot of insulation fibers in my wall cavity samples,

> and get a lot of negative results in situations where subsequent

> opening reveals a lot of mold. Any suggestions?

>

> Connie Morbach

>

\ " CARL E. GRIMES\ " GRIMES@...

> GRIMESHH

>

> Sun May 2, 2010 8:41 pm (PDT)

>

> Connie,

>

> If there is insulation inside the walls then I expect three things:

>

> 1. Some of the insulation will be sucked into the cassette.

>

> 2. The quantities of spores reported per cubic meter are not

> valid. At 15 L per minute you need a minimum of 15 Liters of air

> inside the wall. If you sample for 5 minutes you need an air space

> of 75 L, assuming you get all of it out without pulling in air from

> the room. Then you get a combination of room and wall results,

> not just the wall.

>

> 3. Results will be based on only the tiny location at the point of

> the sample, not representative of the entire space between studs,

> let alone the entire wall. For example, and just the opposite of

> what you sited, a recent sample from an outlet returned high

> enough levels to warrant further investigation. Opening the wall

> revealed tightly pack cellulose showing no signs of dampness or

> mold growth - except for the area right at the outlet where the

> sample was collected. Results were " accurate " for that spot but

> not representative of the wall.

>

> I don't put much faith in wall samples except for answering a very

> specific and relevant question which cannot be answered by

> other means. Even then only qualitatively, not quantitatively.

>

> Carl Grimes

> Healthy Habitats LLC

>

> -----

>

>

[Guest guest]

Thanks Jeff and Carl. I assume a wall full of insulation wouldn't work for

testing but in this house I don't believe the walls are insulated. The attic

had insulation added, including the tops of outside walls and stuffed down I

think but doubt if it goes down very far. I thought it was a reasonable test

since I wouldn't be making a hole in wall. If testing comes up with insulation,

I would realize there was too much insulation for test but knowing ahead of time

I could run into this is helpful, so thanks again.

>

> Connie and Carl,

>

> I would agree with you about testing wall cavities. The results are

> definitely very qualitative and often not meaningful.

>

> If the wall is full of insulation, the fibers filter everything from

> the air flow, and unless the problem is at the outlet, you will not

> see any evidence for mold growth even if it is in the cavity.

>

>