Roof Snow Removal in Eau Claire: When, How and How Much Snow a Roof Can Hold

Roof Snow Removal in Eau Claire: Do You Actually Need It?

Roof snow removal is worth doing when the weight on your roof gets close to what the roof was designed to carry, when the structure starts showing stress, or when snow at the eaves keeps feeding ice dams. Most of the time a normal Chippewa Valley snowfall can stay right where it is. If you see sagging or hear creaking, or the job means getting up on the roof, the roofing contractors in Eau Claire listed on our directory are the people to call.

The useful question for roof snow removal is weight. Two feet of fluffy snow and two feet of wet, packed snow put very different loads on the same rafters, and that difference is what decides whether you grab a roof rake or leave it alone.

How Much Snow Can a Roof Hold in Eau Claire?

A home built under Wisconsin’s Uniform Dwelling Code in Eau Claire County is designed for a minimum roof snow load of 40 pounds per square foot. That number comes from the code’s roof load zone map, which splits the state in two.

• Zone 1, 40 pounds per square foot: the northern part of the state, which includes Eau Claire, Chippewa and Dunn counties.
• Zone 2, 30 pounds per square foot: the southern part of the state, below a line that runs just south of Eau Claire County.

The code says that load is measured straight down over the roof area as seen from above, the horizontal projection, so a steep roof and a shallow roof over the same footprint are designed for the same weight.

What does 40 pounds per square foot look like?

A University of Minnesota Extension report on residential roof snow loads explains it in terms of water. Each inch of water depth weighs 5.2 pounds per square foot, so a roof designed for 40 pounds per square foot carries about the equivalent of:

What is on the roof	Roughly equal to 40 lb per sq ft
Ice	About 8 inches
Settled, compacted snow	About 3 1/2 feet
Very dry, fresh snow	In theory, about 20 feet

The same report puts very dry snow at about 3 percent water, so 30 inches of it melts down to 1 inch of water. Compacted snow is closer to 20 percent water, and ice is nearly all water.

Can a roof fail below its design load?

Yes. UW-Madison Extension lists conditions that let a roof fail at less weight than it was designed for: framing that was never engineered, undersized or wider-spaced rafters and trusses, missing bracing, rot or corrosion from moisture, and extra weight added later, such as a second layer of roofing or equipment hung from the trusses. Older homes and additions built without plans deserve more caution.

Snow Load on Roof: How to Estimate Yours

You can make a ballpark estimate of snow load on your roof by multiplying the snow depth in feet by its density. UW-Madison Extension gives this formula and these approximate densities, in pounds per square foot for each foot of depth:

Type of snow	Pounds per sq ft, per foot of depth
Light snow	5 to 20
Packed snow	20 to 40
Packed snow with ice	40 to 58
Ice	58

Extension’s own example: three feet of light snow at 20 pounds per foot comes to about 60 pounds per square foot, already past the 40 pound design load for Eau Claire County.

For a better number, the University of Minnesota report suggests taking a core sample of the roof snow from top to bottom, melting it, and measuring the water. Multiply the inches of water by 5.2 to get pounds per square foot.

Where does snow pile up heaviest?

Snow piles up heaviest in valleys, on lower roofs below a taller roof, and on the downwind side of the ridge. UW-Madison Extension notes that drifting and snow sliding off an upper roof can add significant load to these spots, so a garage roof under a two-story wall can carry far more than the main roof.

Should I Remove Snow From My Roof? Signs It Is Time

Remove snow when the estimated load is approaching the design load, when the roof shows stress, or when you keep getting ice dams. UW-Madison Extension lists the stress signs as:

• Sagging in the roof line or ceilings
• Trusses or rafters that look bowed or out of alignment
• Creaking or cracking sounds

If you see any of these, get people out of the rooms below and call a pro rather than working on the roof yourself.

Ice dams are the other common reason to rake. Snow on the lower roof melts from attic heat and refreezes at the cold edge, and the National Weather Service recommends pulling that lower band of snow off with a roof rake. Our ice dam prevention guide covers the attic fixes that stop the cycle. Wisconsin code SPS 321.28 also requires an ice barrier at least 30 inches up from the roof edge, and at least 12 inches past the inside face of the exterior wall, on shingle roofs over heated space with a slope of 4:12 or less, so ask about it when you reroof.

How to Remove Snow From a Roof Safely With a Roof Rake

The safest way to remove snow from a roof is a roof rake used from the ground. UW-Madison Extension’s precautions, in order of how I would use them:

1. Stay on the ground. A long-handled roof rake keeps you off the ladder and off the roof.
2. Stand clear of the fall zone. Pulling snow off the edge can let the snow above it slide down all at once.
3. Work the heaviest areas first, such as valleys and drifted lower roofs.
4. Pull it off in narrow strips so the load stays fairly even across the roof.
5. Leave a thin layer. You do not have to remove it all, and that layer protects the shingles from the rake.
6. Use plastic or wooden tools. Never chip at ice on the roof surface, and never put a snow blower on a roof.
7. Do not pile snow on another part of the roof, which only moves the weight.

Watch for power lines when you swing a long rake, and keep the gutters and downspouts clear so meltwater has somewhere to go.

Is it safe to shovel snow off a roof?

Getting on the roof is where most of the risk is. Extension warns that falls from roofs and ladders happen easily in winter, and that sliding snow can knock someone off a ladder or bury a person below. If a crew does go up, Extension says they should be tied off with fall protection and the ladders secured.

When to Call a Pro for Roof Snow Removal

Call a pro for roof snow removal when the roof shows stress, when the snow you need to move is beyond the reach of a rake from the ground, or when the roof is steep, high or icy. A roofer can also check for damage once the snow is off, especially at the eaves where ice dams form.

I could not find a published, sourced price for roof snow removal in the Eau Claire area, so I am not quoting one here. When you call the roofing contractors in Eau Claire on our directory, ask for a written price and ask:

• Do your crews use fall protection on the roof?
• Will you leave a protective layer of snow on the shingles?
• How do you handle ice at the eaves without chipping the roofing?
• Will you clear the gutters and downspouts while you are there?

If sagging or cracking shows up inside, a structural engineer or experienced remodeling contractor can judge whether the framing needs repair before next winter.