The snow is melting, meaning damages incurred over the past months are becoming more visible. This month we asked three jurisdictions in our coverage area for the running total of buildings that folded in some way, shape, or form to the weight of snow, rain, and the heavy combination of the pair. The number, over 50 as of publication, could increase as owners return for warm-weather Tahoe/Truckee time.
Do current codes cover this winter’s snow load in Truckee, Placer County, and Nevada County? How many structures suffered damage from the weight of snow and rain?
Yes, they do! The Town of Truckee is currently regulating the 2022 California Building Code of Regulations, which means anything submitted after Jan. 1 of this year would follow under compliance of these codes. In the past week, the Engineering Association for the Town of Truckee, along with our surrounding communities, got together to discuss what types of damage took place and concluded that damage appeared to be consistent throughout the region. It did appear that structural failure in most cases dealt with older structures that were constructed when much older regulations would have been in place, or structures that were not permitted.
To date, we have 30 structures that have suffered damage from snow and rain. This of course would not cover other miscellaneous items such as broken gas lines or displaced gas meters broken windows due to falling snow or ice. Considering that Truckee has a lot of summer homeowners, my best guess is that when these owners come up to visit this summer this number could increase.
~ Mike Ross, Town of Truckee chief building official
Placer County sustained minimal snow-load damage due to exceptional pre-planning and the resulting well-designed buildings. Eighteen damaged structures pale in comparison to the number of undamaged structures. Of the 18, several were impacted by elements other than snow-loading such as avalanches, sliding snow, and unbalanced unloading of snow causing buildings to lean. What’s the root cause of the well-sustained built environment?
It all began in the 1960s. Eastern Placer County was identified within a special snow region due to the Sierra Nevada Mountains and its known heavy snow accumulation. During that time, the county developed snow standards to assist designers and engineers with snow-load design criteria. Since then, every home and building has been designed to these standards.
While known snow-loading standards are advantageous, engineers go further to protect life and property by including a safety factor. Not to be overly technical, the engineer designs buildings using the county standards and then applies a safety factor. Safety factors demonstrate how much stronger the design is compared to the intended load. Safety factors, often 20%, offer additional capacity to accommodate the unprecedented loading.
The results of well-planned snow-load standards, safety factors, and design considerations of the engineers are evident in the sustained built environment where limited damage occurred.
Cooperatively, we’ve established effective design parameters Mother Nature has time-tested again. My hat’s off to our engineers and design community.
~ Tim Wegner, Placer County chief building official
Permitted and inspected structures built to current building codes, 1990 through today, are strong enough to handle this winter’s extreme snow loads in Eastern Nevada County. With proper maintenance, including the removal of snow on roofs, most structures should be able to handle the snow loads in winters to come. However, with that being said, in unincorporated Eastern Nevada County, at least three residences and one commercial building self-reported damage stemming from the January and February winter storms. We continue to collect damage data as the snow melts and property owners check on their homes.
~ George Schureck, Nevada County building director