Colorado’s harsh winter conditions raise an important question for every homeowner and business owner – how much snow weight can my roof handle? Understanding this limit is a matter of safety and smart property management.
Read on to learn more about snow load requirements, how it is measured, and how to calculate it for any Colorado property.
What Is a Snow Load Requirement in Roofing
A snow load requirement is a safety standard used in roofing to determine how much weight a roof must withstand from accumulated snow or ice. This is an essential consideration for properties located in areas that experience heavy snowfall, such as Colorado. Not meeting the required roof load can result in severe damage, a shorter roof lifespan, and roof collapse.
The load requirement of a state may vary from other states since the difference in snowfall from state to state determines what kind of roof load a residential or commercial building will need to withstand.
Without these critical requirements, many buildings would quickly collapse under the increasing weight of heavy snowfall because they would not be built to sustain such large amounts.
How Is Snow Load Measured?
Snow load is measured in pounds per square foot since every square foot of the roof must be able to hold and withstand the weight of the determined amount of ice and snow, and the mass of the snow is measured in pounds.
This measurement takes into account how much snowfall a particular area gets on average, so a mountainous region such as Clear Creek County in Colorado, which includes towns such as Idaho Springs, has a high roofing requirement of 35 pounds per square foot (PSF) for homes under 6,750 ft elevation. In contrast, houses built higher up in the same area at elevations over 7,001 ft have a higher load requirement of 45 PSF.
Other areas, such as Aspen, have a load requirement as high as 70 PSF (or even maxing out in popular ski areas with load requirements of 125-135 PSF).
For context, most residential roofs in any location should be able to support at least 20 pounds per square foot before reaching a point of stress.
How Do You Calculate Snow Load for a Colorado Property?
Calculating your snow load is simple yet involved.
The calculation method depends on whether you have a pitched or flat roof. The incline of pitched roofs allows the snow to slide off more easily than it would for a flat roof. On the other hand, a flat roof will need to withstand much heavier snow loads as the snow won’t be able to come off quickly as it melts.
By understanding your roof’s snow load, you’ll have a better grasp of just how much your home or building can withstand and whether your roof will do well in an intense Colorado winter as it is.
Calculate the Pitch of the Roof
The first step is calculating the roof’s pitch by measuring rise over run, aka how much the roof slants.
- Measure the horizontal distance (run) from the ridge to the outside edge of the house.
- Use a level to measure how far down it drops vertically (rise) over that same distance.
- Divide the rise by run and multiply by 100 to get your pitch percentage.
For example, if your roof’s rise is 20 ft and the run is 40 ft, you would divide 20 by 40 to get 0.5. In a ratio of twelve (since one foot is twelve inches), that would be 6:12. In this case, the pitch of your roof would be 6:12.
Measure Snow Cover Depth
Once you have calculated the pitch of your roof, it’s time to measure the depth of snow and ice cover on your roof. This makes the calculation a bit involved – there must be snow cover on your roof to get an accurate number.
- Use a measuring tape to measure the distance from the top surface of the snowpack to your roof’s surface.
- Repeat this process in multiple areas along your roof, as the depth can vary depending on wind and sun exposure.
- Add the measurements and then divide by the number of measurements to find the average depth of snow cover.
- Convert this measurement to feet.
- Then, gather some snow and ice from your roof and place it in a container that is 1 ft x 1 ft. You’ll need this for the next step.
Measure and Analyze Snow Type and Density
To accurately calculate, you’ll need to weigh the material you gathered in your container. Once you’ve done that, you can determine the density of the snow by dividing the weight in pounds by one cubic foot (which is also equal to 7.48 gallons) of volume.
Let’s say your cubic foot container weighs 10 pounds, and you have two feet of snow on your roof. That would mean that your roof is holding 20 pounds of snow per cubic foot.
Determine Your Snow Load
Once you’ve calculated all these factors, multiply the depth in feet by the roof’s pitch. Then, multiply that number by the density of it (the weight per cubic foot). That will estimate how much total weight your roof is currently under from the accumulated snowfall.
Note that, with a pitched roof, you may also need to consider certain factors, such as what the roof is made of and the snowfall in your area. It’s not difficult to find calculators online to help you determine an exact measurement.
Frequently Asked Questions
How Much Weight Can a Colorado Roof Take With Snow?
The amount of weight a Colorado roof can take with snow depends on its location, roof type, and pitch. Most roofs should sustain at least 20 pounds per square foot of snow before becoming stressed, but some Colorado roofs can withstand much more, up to 130 pounds per square foot in some areas.
Ensuring your commercial or residential property’s safety during harsh winter weather is crucial for any Colorado resident or business owner. Knowing the snow load requirement for your roof and how to calculate your roof’s load will help you make informed decisions on the steps needed to maintain a safe structure in the winter.
Scott’s Roofing is here to help if you need professional roofing services. As Colorado’s leading roofing experts, we specialize in residential and commercial properties throughout Aurora, Denver, Boulder, Lafayette, Longmont, and Lakewood.
We’re Colorado’s local roofing experts, providing excellent customer service and experience combined with unparalleled quality work and a sustainable mindset.
No matter your location or snow load, we can help!