Adequate Ventilation

Dear NH,
I have a 5-year-old home that I had constructed for my family. Unfortunately, we have started to see a fine gray like staining on the carpets on the interior walls especially near the cold air return and, oddly enough on the ceiling of the home where the trusses are located. We have been able to paint over the stains on the ceiling but have not been able to determine the source of what is possibly causing the problem. We have been told that we may have poor ventilation in the attic, but that does not appear to be a problem. We do have all gas appliances and was wondering if that might be the problem.
M from Midland, Michigan

First and foremost, you should have your heating system checked for adequate ventilation. You may have a dangerous health problem in your home! HVAC (heating, ventilation and air conditioning) pros have often associated large amounts of very fine particulate matter in a home's air to "negative pressure" in the home. Energy efficient modern homes can be too air-tight, not allowing enough fresh air to enter the home to compensate for the fixtures and appliances that blow air out, such as ventilation fans, clothes dryers, fireplaces, wood or coal stoves and your central heating system. Running your clothes dryer, for example, can cause some of the exhaust from your furnace to be sucked back into your home, bringing with it particulates and deadly carbon monoxide! If this is true in your home, your furnace or water heater can be given its own fresh air supply. Contact a HVAC specialist to have testing done and get recommendations.

Other sources of excessive dust are wood burning appliances. Wood stoves, fireplaces and coal stoves can introduce lots of dust into a home, even when they are working properly. This is part and parcel of the "wood burning experience" and those of us who have burned wood come to accept this as a minor inconvenience... though not so minor for folks with sensitivity to dust!

Now... to your staining on the ceiling. Ceiling joists and trusses can create a direct path for the cold from the attic to enter your living space! This is because wood is less of an insulator than the rolled or loose insulation between the joists on the attic floor. These "cold spots" cause normal home moisture to condense on the ceiling… not enough to drip but enough to act as a "dust magnet" and, over time, cause the telltale accumulations of dirt and subsequent staining.

Repainting will eliminate the stains for a while, but because you have not addressed the cause of the staining it will recur eventually. Of course, using an eggshell (or glossier) finish paint instead of flat will help make the surface easier to clean.

One way to lessen this problem is to add more insulation to the attic across the tops of the joists. This will equalize the temperature of the ceiling and (hopefully) eliminate the recurring stains. Of course, eliminating the source of the dust is public health enemy number one!

You mentioned your natural gas appliances. One of the main byproducts of burning natural gas is water vapor. This additional moisture can be a problem in some homes, especially new homes that are built to be very weather-tight. As mentioned in the first paragraph, You can lessen the moisture by increasing ventilation... use the exhaust fan over the stove whenever possible, use the exhaust fans in the bathrooms, etc... even open a window! Hope this helps!

Have a small home repair question for THE NATURAL HANDYMAN? Just click here For more home repair information, visit NH's growing list of original home repair articles and quality links If this information has been valuable to you, please consider making a small donation to support NH's free service to the home repair community! For more information, please visit our "Friends" page

The Natural Handyman Site Directory

Stay Connected with TDS

Little Luxuries

to the Dollar Stretcher newsletter and get a copy
of our ebook
Little Luxuries:
130 Ways to Live Better...For Less
for FREE!

Your Email:

View the TDS Privacy Policy.

Debt Book