A problem with ice and icicles hanging off your roof is generally related to problems with your attic insulation and ventilation. An effective way to solve this problem is to make sure your attic insulation and ventilation meet the standards set by the National Building Code.

With respect to insulation, the standard is R-51, or about 15.5” (39.5 cm) of mineral wool.

The volume of air must be changed at a rate of once per hour. So once the insulation is installed, you need to install enough air outlets to remove all the air from the attic in compliance with National Building Code standards and taking the manufacturers recommendations into account. By the same token, it is very important to free up the ledges at the roof edge and make sure the space between the insulation and the wood deck is sufficient to ensure a good air flow to the air discharge accessories on the ledge. The space required by the National Building Code for the surface area is 63 mm. If the insulation is fixed using deflectors at the junction of the sloping roof and the outer wall, the clearance should be at least 25 mm.

Several products, such as “Styrovent,” are available on the market to perform this task. In addition, it is important to check that there are no possible inlets other than the ledge at the bottom of the slope, as this will make your air exhaust accessories less efficient.

In conclusion, remember the basic principle in physics whereby the volume of air that goes out of the attic is proportional to that which goes in and vice versa. So if no air can get in, no air can go out, even with the best fans.

By making these few changes you will notice significant changes in your building.

For improved ventilation or for any other advice, feel free to contact us.