Caution Regarding Air Sealing The Basement Area:
Homeowners in Greenville, Rockford, or Grand Rapids, may not be aware of this potential problem when weatherizing their home for drafts. Commonly called air sealing. When undertaking air sealing, be careful of a few things when it comes to basements. There may already be hazards without doing any air sealing, but it may be aggravated if not addressed before, or during air sealing. Caution must be taken.
Homeowners are always searching for the right energy efficiency tips.
When it comes to the basement, you have to understand there's a relationship between having enough combustion air(venting) and air sealing: sealing up a home will reduce the amount of air entering the home(and leaking to the outside). The best way to determine if you have done enough and not too much sealing is to do a blower door test.(we'll explain in a latter blog article)
When moisture might be an issue. Look for any signs of mildew, mold or structural rotting. If moisture is causing a problem then take control of the moisture source before air sealing.
Not Enough Combustion Air(oxygen):
If there are gas appliances, carbon monoxide might be an issue. In general a carbon monoxide detector should be installed as part of any air sealing effort.
Backdrafting problems can develop if changes made in the house, such as general air sealing or installing a central vacuum system or a high-velocity kitchen range hood fan, affect air pressure. Backdrafting is a dangerous condition that should be corrected. (It's the laws of physics.) The source of the combustion air for the furnace must be adequate and not come from the wrong location. Pulling air from, say a bedroom is not a good idea.
Having an open or insufficient return air system is a primary concern. Open returns provide a significant depressurization source in the immediate vicinity of the unit. Standards range from simply ensuring that the appliances work under the worst case conditions, to installing combustion air that meets current building code. Heating equipment may have an issue. If there are any signs of backdrafting or inefficient combustion, have it tested by an HVAC technician.
Basements And Crawlspaces:
Next, inspect and measure the thickness of any insulation in unfinished basement ceilings and walls, or above crawl spaces. If the crawl space is not ventilated, it may have insulation on the perimeter wall. If your house is relatively new, it may have been built with insulation outside the basement or foundation wall. However, this insulation would not be visible because it would be covered by a protective layer of stucco, plastic, fiber glass, metal flashing, or a rigid protection board.
To do the total job right, basement air sealing should only be undertaken by contractors who are comfortable assessing houses for potential moisture problems and who are willing to undertake combustion safety tests, to ensure air sealing does not create issues with moisture or backdrafting of combustion equipment like your gas furnace or hot water heater.
Here, we've air-sealed at the band joist.
Here's a pretty good resource for homeowners from EnergyStar. CLICK HERE. (Go To The Page On Basements.)
Or, this may be a time to bring the professional who can do an energy audit or the HVAC technician who understands this.