How to Prepare Your Roof for Snow Loads Guide for Eastern Washington Homeowners & Contractors
Why Snow Load Matters More Here Than You Might Think
If you’ve lived in the Spokane area, Colville, or Kettle Falls through more than one winter, you already know our snow isn’t always the light, fluffy stuff you see in the movies. Eastern Washington gets a mix — dry powder in cold stretches, but also heavy, wet “Cascade concrete” snow during warmer storm systems and rain-on-snow events. That variability is exactly why roof snow load prep trips up so many homeowners: a foot of powder might weigh 3-5 pounds per square foot, but a foot of wet, dense snow can weigh 20 pounds per square foot or more. Same depth on your roof, wildly different stress on your rafters.
Spokane County’s minimum roof snow load requirement is 30 psf, with ground snow load commonly figured around 39 psf for city engineering standards. But that’s a floor, not a ceiling — some higher-elevation areas around Stevens County and the hills outside Colville and Kettle Falls can see ground snow loads well over 100 psf, sometimes reaching 150 psf in drift-prone spots. If you’re up on a ridge or in a spot where wind piles snow against a roofline, your real-world load could be much higher than what a standard code minimum assumes.
What This Means for Your Specific Property
Before you do anything else, it’s worth finding out what your actual site-specific snow load is. Spokane County has mapping tools for this, and Stevens County building departments can point you toward the same kind of data for Colville and Kettle Falls addresses. This isn’t just bureaucratic box-checking — it tells you how much margin you actually have before a heavy snow year becomes a structural problem.
How to Tell If Your Roof Is Handling the Load
Most roofs in our area are built to handle a normal winter without any drama. But every few years we get a stretch of storms that stack up fast, and that’s when we start hearing from customers at our Airway Heights, Colville, and Kettle Falls stores asking how to know if they’ve got a problem.
Warning Signs You Shouldn’t Ignore
- New or worsening sagging along the ridge line, or a ceiling that looks like it’s bowing.
- Creaking, popping, or cracking sounds coming from the attic or roof framing, especially during or right after a heavy snowfall.
- Doors and windows suddenly sticking that opened fine before the storm — this can mean the frame is flexing under load.
- New cracks in drywall near ceiling lines, particularly where walls meet ceilings.
- Visible bowing of rafters or trusses if you go up in the attic with a flashlight.
If you see any of these, the advice from structural engineers and emergency management resources is consistent: get out of the affected rooms and call a structural or roofing professional right away. Do not go up on the roof yourself to investigate. A roof under stress is not the place to be testing your weight.
Rules of Thumb for When to Act
You don’t need to wait until things look dramatic. General guidance suggests starting snow removal once you’re at roughly 75% of your roof’s design load, and treating 90% as an urgent situation. For a roof rated at 30 psf, that means paying close attention once accumulated snow — factoring in density, not just depth — gets into the 22-27 psf range. Since dense wet snow can hit that number with far less depth than powder, don’t just eyeball inches on the roof. A foot of heavy spring-type snow in the Spokane area can be a bigger deal than two feet of dry January powder.
Safe Snow Removal Practices for Eastern Washington Roofs
Once you’ve decided removal is warranted, how you do it matters almost as much as when. We sell a lot of roof rakes every winter at all three of our locations, and there’s a right way to use them.
Roof Raking From the Ground
A telescoping roof rake lets you clear snow from the eaves without ever leaving the ground — this is the safest option for the vast majority of homeowners. Work in horizontal strips, pulling snow down in layers rather than trying to scrape everything off in one pass. Focus especially on the lower edges of the roof, since that’s where ice dams tend to form and where the load transfers most directly onto the eaves and gutters.
A few practical tips:
- Leave 2-3 inches of snow on the roof surface rather than scraping down to bare shingles — this protects the shingle granules and roofing material from being torn up by the rake edge.
- Remove snow evenly from both sides of the roof. Clearing only one slope of a gable roof can create an uneven load that stresses the framing in ways it wasn’t designed for.
- Never use a metal shovel or any sharp-edged tool directly on the roof. Cold shingles are brittle and crack easily.
- Skip the salt or de-icing chemicals on the roof itself — they corrode metal roofing and gutters and can damage shingles, plus that runoff ends up in your yard and landscaping.
When to Call It and Bring in a Pro
Steep roofs, multi-story homes, and anything requiring you to actually get up on the roof surface are jobs for a professional with proper fall protection and equipment. This is especially true across our service area, where a lot of homes sit on sloped lots or have complex rooflines that make ground-based raking difficult. If your roof pitch is steep enough that a roof rake can’t reach the areas that need clearing, or if you’re dealing with a two-story home with a steep gable, it’s worth paying for a professional snow removal service rather than risking a fall.
Ice Dams, Heat Cable, and Snow Retention Systems
Snow load isn’t just about total weight — ice dams create their own set of problems by trapping meltwater behind a ridge of ice at the eaves, which can back up under shingles and cause leaks and rot. This is a classic Eastern Washington problem because of our freeze-thaw cycle: sunny days melt snow on the upper roof, that water runs down to the colder overhang, and refreezes right at the edge.
Heat Cable Systems
Heat tape (also called heat cable or heat trace) is the standard fix. It runs along eaves, through roof valleys, and inside gutters and downspouts to keep a continuous meltwater path open so ice can’t dam up. Self-regulating cables, which adjust their output based on temperature, are generally worth the extra cost over constant-wattage cables because they run more efficiently and are less likely to overheat or waste energy on marginal days.
For a typical single-story home with straightforward eaves, a plug-in DIY kit with clips is a reasonable weekend project. We carry cable in various lengths and wattages (typically 5-8 watts per foot) at our Airway Heights, Colville, and Kettle Falls locations, along with the mounting clips and controllers you’ll need. For homes with complex rooflines, multiple valleys, or dormers, it’s worth having a contractor design the layout — heat cable that doesn’t cover the right spots is a common and expensive mistake.
One important thing to understand: heat cable prevents ice dams, but it does not add structural snow load capacity. Don’t treat it as a substitute for addressing an undersized roof.
Snow Retention Hardware for Metal Roofs
If you’ve got a metal roof — increasingly common on newer builds and outbuildings around Colville and Kettle Falls — you need to think about snow retention differently than a homeowner with asphalt shingles. Metal roofs shed snow in sudden slides rather than letting it melt gradually, and a sheet of snow and ice sliding off a metal roof can do real damage to whatever’s below, from parked vehicles to people walking underneath.
There are three general categories of snow retention hardware:
- Snow guards or spikes — individual devices installed in a staggered pattern that grab the bottom layer of snow and slow a slide. Good for low to moderate snow accumulation.
- Snow bars or dams — continuous horizontal bars mounted across the roof, often clamped onto standing seam panels without piercing the metal. Better suited to moderate-to-heavy accumulation.
- Snow fences or rails — pipe-style assemblies near the eave designed to hold back an entire snowpack at once. These are the heavy-duty option for steep metal roofs in high-snow areas.
For most homes in the Spokane area with moderate roof pitches, snow guards or bars are usually sufficient. If you’re up in the hills around Kettle Falls with a steep metal roof and heavier average snowfall, a full snow fence system is worth the investment, especially over entryways, walkways, or parking areas.
Common Mistakes We See Every Winter
After years of selling roofing and snow removal supplies across Eastern Washington, a few mistakes come up again and again.
Assuming Your Roof Matches the “Standard” Load
The code minimum is just that — a minimum. Homeowners who assume their roof automatically handles whatever snow falls, without checking their site-specific load, are the ones most likely to get caught off guard. This is especially true for additions, carports, and decks, which sometimes get built to a lower standard than the main house.
Treating Manufactured Homes Like Standard Construction
A lot of manufactured homes are factory-rated for only 20-30 psf snow load. If you’re in a rural part of Stevens County with real winter exposure, your actual local snow load may exceed that rating significantly. If you own or are buying a manufactured home in our area, it’s worth verifying the factory design load and talking to a contractor about whether a supplemental “snow roof” or reinforcement makes sense.
Uneven Snow Removal
Clearing snow off just one side of a roof, or only the section you can easily reach, creates an imbalanced load. It seems harmless, but it can put unexpected stress on trusses that were engineered to handle symmetric loading.
Installing Heat Cable as a Band-Aid
Heat cable solves ice dams. It does not solve a structurally undersized roof or a sagging ridge. If you’re seeing structural warning signs, don’t just wrap the eaves in heat tape and call it done — get a professional opinion first.
Going Up on a Snow-Covered Roof
This one bears repeating because it’s the most dangerous mistake on this list. Snow and ice on a roof surface, combined with cold temperatures and a sloped surface, is a serious fall hazard. Ground-based tools and professional services exist specifically so you don’t have to take this risk.
Planning Ahead: A Simple Seasonal Checklist
Before the first real snow hits the Spokane area, Colville, or Kettle Falls each year, run through this list:
- Clean gutters and downspouts thoroughly — clogged gutters make ice dams worse.
- Check attic insulation and ventilation; a well-ventilated, evenly cold roof deck melts snow more evenly and resists ice dams better than a roof with warm spots from heat leaking up through the attic.
- Inspect and test heat cable systems before the cold sets in, not after the first ice dam forms.
- Confirm you have a roof rake on hand and that it reaches your eave height.
- If you’re unsure of your roof’s design snow load, contact your county building department or a structural engineer before winter, not during a storm.
- For metal roofs without snow retention hardware, consider adding guards or bars before the season starts, since installation on a snow-free roof is far easier and safer.
Getting ahead of this in October or November beats trying to solve it during a February storm every time.
We stock roof rakes, heat cable and heat tape systems, snow guards and snow retention hardware, gutter accessories, and roofing materials at our Builders Supply & Home Center locations in Airway Heights, Colville, and Kettle Falls. Our team has been helping Eastern Washington homeowners get their roofs ready for winter since 1979, and we’re happy to help you figure out what your specific roof and property need before the snow starts piling up. Stop by any of our three locations or shop online now at https://bldrsupply.epicor-inet.com/departments.