12/03/2014
Factors in cold weather that can increase the chance of damage to roofs from ice damming.
With the recent dip in temperatures, it has raised our concern of the increased risk of damage to roofs, particularly when ice forms along the edges creating a ridge that pools the snow and ice melting from higher on the roof. To help address this topic, we called on Jim Pearson, who has worked in the indoor air quality field for over 35 years and who has dealt with a lifetime of ice forming on roofs from having lived in Montana his entire life!
We could think of no better expert to ask to explain the phenomenon of ice dams than Jim at TheCleanAirExpert.com. Please click “share” to help spread the important information Jim details in the following short article:
Ice Dams, Condensation in Attics, & Mold!
By Jim Pearson, CMH
Ice dams, condensation and the potential for the formation of mold in the attic can quickly damage structural framing materials and insulation layers. The resulting mold growth can potentially contribute to poor indoor air quality and ill health of the occupants.
Ice dams are caused by where ice and snow build up on the unheated edges of your roof. Ice dams usually form where there are icicles hanging off your eve. This indicates a warmer roof deck due to breaches in your attic insulation. The snow melts more slowly at the edges of the roof (over the eves) than the main surface area over the living quarters. This frozen ice and snow backs water up under shingles and wets the roof sheathing and rafters.
Condensation caused by high humidity in attics can also cause mold to form. This moisture will begin to deteriorate both the framing and sheathing and also degrades the effectiveness of the attic insulation. The major cause of attic condensation is from moist air from the living areas below.
Adequate ventilation should exist in all attics to allow this moisture to escape to the outdoors. Bathroom and kitchen vents as well as dryer vents should all terminate outside of the structure to minimize excess moisture within the structure.
Make sure you don’t fall prey to unusually cold or snowy weather conditions causing this potentially damaging condition to your property. Here are some things you can do to be proactive:
1. Check your attic for condensation or moisture on rafters and wood decking.
2. Look for black (rust) marks around shingle nails protruding through the roof deck into the attic and evaluate any water staining indicating a leak.
3. Make sure all exhaust vents protrude through the roof deck to the outdoors and that all soffits and gable ends or ridge caps are open for ventilation.
4. Use a strong light and examine the wood for mold. It should look black, green, grey, or white and will usually look fuzzy and grow in round colonies ranging from the size of a pea to about a half-dollar. Mold also grows in patches. If you think you have mold in your attic, call a mold remediation professional.
Photo credit: diyadvice.com