Every time we get a big snowstorm, my phone rings with homeowners asking the same question: should I be worried about the weight on my roof?
The short answer for most homes along the valley floor is no, you are probably fine. But I would rather give you the longer answer so you actually understand what is happening up there and know when it does make sense to pay attention.
How much snow load is a Utah roof actually built to handle?
Residential roofs in Utah are engineered to handle our snow loads. Building codes in Davis and Weber counties require roofs to support a ground snow load of 30 to 50 pounds per square foot, depending on the specific location and elevation. Your roof structure, the trusses or rafters, the decking, all of it is built to carry that weight.
To put that in perspective, a foot of fresh, fluffy powder weighs about 3 to 5 pounds per square foot. A foot of wet, heavy snow can weigh 20 pounds per square foot or more. And old compacted snow or ice is even heavier. So it is not really about how deep the snow is. It is about what kind of snow it is.
When should you actually start worrying about snow on your roof?
There are a few situations where I tell homeowners it is worth keeping an eye on things.
If you have had multiple storms back to back without any melting in between, and you are looking at two or three feet of accumulated snow, that is worth thinking about. Especially if it has rained on top of the snow, because wet snow is dramatically heavier than dry.
Flat or low slope sections are more of a concern than steeply pitched roofs. Snow slides off a steep roof. It sits on a flat one. If you have a flat roofed addition, a covered patio, or a garage with a low pitch, keep an eye on those areas first.
Older homes can also be a consideration. If your home was built before modern building codes were updated, the roof structure may not meet current snow load standards. That does not mean it is going to collapse. It just means the margin is thinner.
And here is a big one that people miss: drifting. Wind pushes snow into piles. If you have a two story section next to a one story section, snow from the upper roof slides and drifts onto the lower one. That lower section can end up with two or three times the snow load of the rest of the house.
What warning signs mean your roof is under too much stress?
If your roof is under heavy snow and you notice any of these things, call a professional:
Doors or windows that suddenly will not open or close properly. This can mean the frame is shifting under structural stress.
Cracking or popping sounds coming from the ceiling or attic area. Some noise during temperature changes is normal. Loud, repeated cracking is not.
Visible sagging in the ceiling or roofline. If you can see it from inside or outside, something is under serious stress.
New cracks appearing in interior drywall, especially around door frames.
Should you remove snow from your roof?
For most homes in most winters, no. Your roof is built for this. Climbing up on a snow covered roof is dangerous and you can easily damage shingles in the process.
If the situation looks serious, call a professional. This is not a DIY project when structural safety is involved.
If you do need to remove snow, a roof rake from the ground is the safest approach. Pull the snow off the lower three or four feet of the roof. You do not need to clear the whole thing. And never use a shovel, ice pick, or anything that can gouge the shingles.
Worried about snow load or want to know if your roof structure is up to the task? We will come take a look and give you a straight answer. Contact us anytime.
"It was done right before last huge windstorm and not even one shingle lifted or blew away. Highly recommend him and his crew."Douglas Hunt , Google Review