How to Stop Ice Dams – Part 1

Ice Dams can be a major problem for some home-owners in colder climates. What is an Ice dam? How do I stop them from forming?


If you have snow that has piled up on your roof and you start seeing icicles forming from your eaves or rain gutters, this could mean you have ice dams forming under the snow. There are a few reasons why ice dams form and we will be identifying the main reasons in this three part blog.

When an ice dam forms on your roof, it can stop the water from flowing downwards freely. This causes a pool of water that can creep under the roofing structure and into your home. Every year thousands of dollars are spend by homeowners on home repairs because of damage causes from ice dams.

Ice Dams are caused by melting snow re-freezing near the eaves.


Not enough insulation in your attic is one of the main reasons for an ice dam forming. When you heat your home by a pellet stove, fire place or HVAC, the heat naturally wants to rise towards the ceiling. As it migrates upwards it will enter the attic space. The less insulation you have above the ceiling, the more heat will enter the attic. The more heat that gathers in the attic. . . . . again, naturally wants to rise and contacts the bottom side of the cold roof sheathing. When warm air meets cold air it causes condensation that can drip water into the house but also causes the snow to melt on the roof. As this melts the snow, the water runs down the roof. When it reaches the eaves, it freezes because there is no heat past the outside wall. This is where an ice dam occurs and why it has that name. It is a dam that stops the water from flowing down the roof.

As the red arrow above shows a low level of insulation the joist can be seen. The recommended level of insulation is R-38 which is about 15 inches. Check your local building department for the acceptable amount of insulation for your climate zone. By increasing the insulation from a poor level like this photo to the right, too a R- 38, you will reduce the heat rising from the living space into the attic that melts the snow and forms icicles and ice dams.


Another way heat enters the attic, as seen to the left, a dryer vent or kitchen hood vent that does not exit out the wall, gable side or roof top. This dumps hot air right into the attic. Voids in the framing without insulation also seeps hot air into the attic and can heat up the attic, causing ice dams.

Titanium® PSU30 is a self-adhered synthetic roofing underlayment that protects your roof deck from ice dams when installed.  This 45 mil peel and stick underlayment works well for steep slope roofs greater than 4/12 (anything with a lower slope and pitch should be refer to local building codes) pitch because it seals the roof deck with a modified rubberized asphalt adhesive that is installed under the primary roofing material. Titanium PSU30 has a tough, rugged surface and self seals at the laps so water cannot intrude.  PSU30 should be laid from the eave up the roof at least three feet past the outside wall on new construction. Titanium PSU30 will fight against water intrusion if ice dams form on your roof.

So having a good level of insulation in your attic, helps stop the heat from rising and melting the snow on your roof that causes ice dams. For more information of the full line of Titanium roofing underlayments visit

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