We don't have many brick homes around here in central Vermont. I recently visited a one-story ranch home that was built with exterior walls of hollow core CMUs (concrete masonry units), a brick exterior and a sheetrocked interior that is strapped to the CMUs, which are filled with vermiculite insulation. I am looking for advice from auditors who have experience with this type of construction. Would you feel comfortable doing a BDT (blower door test) that depressurizes the house? What concerns would you have about this?
Brad - thank you for your insights. I listed a home for sale with that Whisper Green fan - loved it! I'll check it out. THANK YOU!
I appreciate all the insights I can get.
As a realtor, having good sources of information is key to my business. All of the experiences and products I've used have been bad and good experiences and shared equally with caveats to my clients. They appreciate having an idea about products as well!
Which is why I always measure bath fan flow (with the Energy Conservatory pan and DG-700 meter) and try to verify where and how it is exhausted.
I have seen brand brand new Panasonic bath fans vented with plastic flex duct into voids, kneewalls and attics, and I have seen one that was installed that did not have the shipping tape removed from the damper at the fan!
During our hot summer months, the odor that is created in my attic is noticeably bad and it infiltrates my house via the attic access in my master closet - of all places to have an odor created! I've lived in the house now for 2 years and can tell it's coming from the attic.
The Icynene installer took samples of both Icynene and the old cellulose, put them in baggies, and laid them in the sun. Both smelled equally as bad and my guess is that it's the cellulose The lower roof pitch and installed Icynene have created a small enough space (house is 1494 sq ft) that the old cellulose has literally permeated all of the Icynene. The smell is sickening.
After the ducts were aerosealed, the smell diminished greatly, but I can tell it's still the old cellulose.
I also had an air quality test done and there is no mold or anything toxic, thankfully.
Thank you for the brand recommendations for the fans. Definitely going to resesarch.
Jan, you bring up another possible source of that bad odor, the Icynene. If the mixture of Part A and Part B is not in the proper ratio, you will get chronic out-gassing of odors. I previously mentioned the possibility of Ammonium Sulphate in the cellulose as the culprit, but that would smell like ammonia, especially when the cellulose is damp (which is a possibility if cooling ducts are not insulated). I have never known cellulose to give off any other type of obvious and objectionable odor, and I have been in contact with lots of old cellulose in attics.
I would not be asking the Icynene installer if his product is the culprit. Do you think that he/she would truthfully tell you if it were their fault?
Good point Brad. I wonder if there is something IN my attic that was not detected and is now encapsulated in the attic, in the cellulose?
HMMMMM..... A lot to think about. Thank you again for being a sounding board in this thread. Didn't mean to consume the thread, but the topic was close enough to comment and give me thoughts on my issue.
Have a great weekend!
A few quick thoughts - main issue is in the summer with open cell? If so I would strongly check into that due to moisture drive is inwards during the heat of the day & many times people notice an odor it is due to improper mix
Assuming OC is issue --- Cellulose has that smell, well I am also sure so would fiberglass, old clothes left up there, etc... it has probably been absorbed & needs to go. You may also be looking into spraying the whole attic with KILZ or something similar after any foam issues have been resolved
Cellulose is the real issue - pretty much the same as above which might include a barrier being sprayed on the foam
Who to call - look for an SPFA certified inspector or call in the manufacturer directly, but first I would get rid of all that cellulose & clean like it is nobodies business (including air sealing)
As an FYI, most block walls (in many areas) have nothing to do with vermiculite or are insulated with it
Thank you for your advice Sean. The cellulose will be removed very soon and I'll make sure they clean it up properly. I already aerosealed my ducts so that should help tremendously. I'd like to give it some time before another approach, but will definitely consider your advice should this NOT resolve the odor issue.