[Greenbuilding] air gap in walls

[JAY WALSH]

Sounds like it could be one of several things:

Air Conditioner / Heating Ducts
The air conditioner can cause this kind of smell when first turned on for the
season and comes from something in the condensation tray, coil or air filter. 
Cleaning with vinegar should clean this up. Also look into the forced air
system, filter etc for a similar issue.

Dead Animal
Dead animal, mouse, in the original wall of the house. If this room gets lots
of sun late in the day it maybe heating the original wall more now that the
room is enclosed. Dead mouse may also be in the ductwork.

Mildew/mold
As mildew grows, it leaves behind a musty, sour-like odor. Most mildews are
caused by an overgrowth of it's close cousin, mold.

Off Gassing of Materials
Any new construction should be well ventilated for “at least” one week.  
If the room has been closed up and allowed to overheat by Sounds like it could
be one of several things:

Air Conditioner / Heating Ducts
The air conditioner can cause this kind of smell when first turned on for the
season and comes from something in the condensation tray, coil or air filter. 
Cleaning with vinegar should clean this up. Also look into the forced air
system, filter etc for a similar issue.

Dead Animal
Dead animal, mouse, in the original wall of the house. If this room gets lots
of sun late in the day it maybe heating the original wall more now that the
room is enclosed.

Mildew/mold
As mildew grows, it leaves behind a musty, sour-like odor. Most mildews are
caused by an overgrowth of it's close cousin, mold.

Off Gassing of Materials
Any new construction should be well ventilated for “at least” one week.  
If the room has been closed up and overheated by the strong Western sun, it
may have caused some  off-gassing or increased mold growth. Construction glues
and the glues used in interior plywoods, particle board etc will off-gas
formaldeyhyde more with an increase in temperature. Also the increased heat
and humidity in the space may have started some mold growth which can also
have a sour odor. 

Keep digging, you'll find the source.

Sincerely,

Jay Walsh
Center for Ecological Technology

> Stephen Collette wrote:
> > Hello everyone,
> > 
> > I did an inspection on a house this week that had odour issues. This  
> > was a new west addition (300 ft2) to the existing farmhouse. It is a  
> > sunroom with heaps of windows and half a dozen skylights. A sort of  
> > octagon sunroom. Heated with radiant floor, electric baseboard and  
> > tied into the homes existing forced air. The house has it's own air  
> > con as well, and the addition has a self standing wall mounted unit.   
> > The homeowner complained of a sour smell. The homeowner DID request  
> > all of those things be installed, as he called himself a britches and  
> > belt kind of guy.
> > 
> > The builder installed window seats around most of the octagon. He  
> > spray foamed the walls and cathedral ceilings (3/12 pitch inside and  
> > out) with Icynene. 4 inches of it.  For the larger window seats, he  
> > left the rest with just air.
> > 
> > Construction from the outside in-
> > Mabec wood siding
> > typar
> > chipboard
> > Icynene and 2X6
> > air gap
> > poly
> > drywall
> > 
> > The window seats are about 18 inches. It seems odd to have this air  
> > gap.  I would have figured filling it with something or put the poly  
> > closer to the insulation. I'm concerned about moisture issues with  
> > this build up. I would appreciate any thoughts on this one.
> > 
> > I'm in Lakefield, ON just northeast of Toronto, and considered cold  
> > climate, despite the global warming thing going on here.
> > 
> > Thanks
> > 
> > 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
> > 
> >