Dangerous Snow Load Accumulating

Roofing Snow Load

Pavel Gonchar Renoteck News, Roofing Resources

Just when you think you have seen the last snowfall of the winter, another dump arrives. You need to remain diligent about the snow load (weight) your roof is carrying to prevent structural damage.

These are indicators that your roof is under stress.

  • Unusual sounds emanating from the roof or the supporting walls
  • Ceiling sagging
  • Cracks developing in the drywall or plaster
  • Movement of the walls
  • Doors becoming difficult to open and close
  • Water leaks that appear after a snowfall
  • Sag in the roof line

Certain design features of your roof can contribute to these issues. Dormers and valleys, chimneys, overhanging trees, minimal sloping and rough roofing material can result in excessive snow and ice accumulation.

From the ground you may be able to remove excess snow using a snow rake, but great care must be taken. The snow is heavy and can easily cause injury. Give serious thought to using a snow removal company that carries insurance in case of a mishap.

Structural Damage Caused by Excessive Weight of Snow

Structural Damage Caused by Excessive Weight of Snow

It is important not to confuse amount of snow with the weight of the snow. 12 inches of powder can weigh less than 2 inches of the wet stuff. Building codes consider geographical location, snowfall records from the past and the resultant snow load expected. Considerations may be slightly different between Calgary and Edmonton but The National Building Code deems a roof must be designed to support a minimum of 1 kilo Pascal (21 pounds per square foot) or higher. These same requirements may not apply to small buildings such as sheds. You will also want to remove heavy snow from the roof of your out-buildings.

Roofs for large buildings are designed factoring in 1-in-50-year snow load events (Snowmageddon!) The shape of the roof and potential accumulation patterns also affect the calculations.

Building codes, materials used, and designs have changed over time. This does not reflect poorly on an older home. Many older homes have proven themselves successful with good performance over time.

During the construction phase, Renoteck will answer all your questions and concerns regarding your roofs performance. Alberta has a challenging winter climate that can have a serious fiscal impact on your home. Your roof is the first line of defence to protect your investment.