How to Stop Ice Dams – Part 2


As we learned in Part – 1 Ice Dams can cause much damage if your insulation level is low and the roof is not protected by Titanium PSU30. The heat from the living space causes the snow on the roof to melt and then forms ice dams when it refreezing near the eaves of your home. Did you know having a good ventilation system in the attic can help stop ice dams and icicles from forming?

Warm air in your attic melts the snow as seen in this photo where the black roof is showing. By having a properly designed attic ventilation system, it will reduce the chance of the heat melting the snow on the roof by cooling the attic space and exiting the warm air out of the attic. One way to exit the hot air is to install a ridge vent system. This will allow an average of 12-16 square inches of ventilation per foot depending on what type of ridge vent you use. The National Roofing Contractor Association recommends 1 square foot of ventilation to 300 square feet of attic space and 1 square foot of ventilation to 150 square feet of attic space if a vapor barrier is present.

Ridge vent exits hot air out of the attic.


Using intake and exhaust ventilation allows your attic to a closer temperature to the outside air. This is important so the heat from the living space entering the attic doesn’t affect the snow on the roof as much. It limits the melting of the snow that causes ice dams. The goal is 50% intake and 50% exhaust.  As the attic starts to warm up a few degrees the air naturally wants to rise. It migrates to the exhaust vent system you have and exits out the attic causing air to be pulled into the attic at the intake. The photo shows a low profile ridge vent covered with ridge cap shingles. Warm air is drawn to the ridge that is cut out, about 3/4 of an inch on each side. It then exits out the black ridge vent that is water proofed from the ridge caps. This design has baffles to resist wind driven rain.

Intake vents can be holes in the soffit’s that are screened or freeze block vents on overhangs. This is a continual supply of colder outside air that flushes out the warmer air that causes condensation or the warmer air that heats the underside of the roof deck. This movement of air helps control ice dams from melting snow and is one way to solve ice dam problems.

Of course having Titanium PSU30 installed under the roofing near the overhangs will seal the roof deck from any seeping water from ice dams. This peel and stick product is specifically designed to protection roof decks with 2:12 or greater slopes using all types of roofing materials including; metal, tile, shake, slate, and both asphalt and synthetic shingles. Using Titanium UDL30 synthetic roofing underlayment in the field, these 2 products (UDL30 & PSU30) offer a unique combination of safety, security and simplicity. See Titanium PSU30 Brochure.

For more information of the full line of Titanium Roofing Underlayments see the contact information at the bottom of the page. For a distributor of Titanium products close to you search here.

All data and information appearing on this site is anecdotal in nature, reflecting the contributor’s personal experience and not fact-based research and, therefore, to be used for information purposes only. Read full disclaimer