Clearing snow off decks safely

Does snow on a deck need to be cleared at all?

Not always. A deck nobody uses in winter, with a light, even cover of snow, is often fine left alone until it melts. Snow on a deck becomes worth clearing for three reasons: people need to walk on it (to a door, a hot tub, stairs or a dog run), the load is building beyond a normal snowfall, or snow is piling up against the house where meltwater can reach the wall and door thresholds.

The first reason is the most common. Back decks are often the everyday entry for a household, and steps and landings are where winter falls happen. OSHA's winter guidance advises clearing walking surfaces of snow and ice as quickly as possible after a storm and taking short, slow steps where ice cannot be avoided.

How much snow can a deck hold?

That depends on how it was designed and built, and only the design or a qualified professional can tell you for a specific deck. For context, the American Wood Council explains that the member and connection sizes in its DCA 6 prescriptive deck guide are based primarily on a uniformly distributed live load of 40 pounds per square foot plus a 10 pound dead load, and that the same criteria can be applied conservatively to a deck carrying a uniform 40 pound snow load, but only where the deck is not prone to sliding or drifting snow.

Snow weight varies widely. FEMA's Snow Load Safety Guide puts a foot of fresh snow at about 3 pounds per square foot when light and dry and about 21 pounds per square foot when wet and heavy, with an inch of ice a little under 5 pounds per square foot. A deck carrying a modest layer of dry snow is a very different situation from one buried under wet snow, ice and whatever slid off the roof.

Why are decks under rooflines a special case?

Because snow slides and drifts onto them. FEMA describes how snow from a higher roof can slide onto lower surfaces below and accumulate there, and how wind deposits drifts in the shelter of taller parts of a building. A deck directly below an eave or tucked into a corner of the house collects both, which is exactly the condition the American Wood Council excludes from its simple 40 pound snow approach.

If your deck sits under a roof that sheds snow, keep an eye on the slide zone after storms and warm spells, and keep people off that part of the deck while snow or ice is still on the roof above. Our guide to icicles and roof snow slides near entrances covers that hazard, and when roof snow needs removing explains when the roof itself is the concern. If the deck shows sagging, cracking or loose connections, stop using it and have it inspected.

What is the safest way to shovel a composite deck?

Follow the manufacturer. Trex's winter care guidance says metal shovels can damage composite materials, making plastic shovels the safest choice for its Transcend, Enhance and Select lines; that certain materials can scuff or scratch a deck; and that shoveling with the direction of the boards minimizes the risk of dings and dents. For light dustings it suggests a broom instead of a shovel. For older-generation decks, it says never to use a metal snow shovel.

Trex also calls the manufacturer the most reliable resource for snow removal advice. Composite brands and product lines differ, and warranty terms can depend on following their care instructions, so find your deck's brand and line before winter and read its care guide.

What about wood decks?

The same principles protect wood. A plastic shovel or a shovel with a plastic edge, pushed along the boards rather than across them, is far less likely to catch board ends or gouge soft wood than a metal blade driven across the grain. Leave a thin layer rather than scraping hard on a finished surface, and let the sun take the rest where it can.

Do not chip at ice on any deck. A shovel corner or an ice chopper will cut the surface long before it breaks the ice free. Treat ice with an appropriate melt or traction product instead, as below.

Which ice melt is safe on a deck?

Check your deck maker's guidance first. Trex says calcium chloride or rock salt can be used to melt snow and ice on its decking, and that on older products such as its Accents line they may be used but should be rinsed off as soon as possible. Other manufacturers and wood finishes may say something different, and products that are fine on a deck may still harm plants below it.

Remember where the runoff goes. Meltwater from a treated deck drips through the gaps onto the ground and plantings under and beside it. Our ice melt guide explains how each product works, pet-safe ice melt covers paws, and how de-icing salt damages plants and concrete covers what happens below. Sand gives traction without melting, but check your deck maker's guidance before using it, and expect to sweep it off and keep it from tracking indoors.

Where should snow from a deck go?

Off the deck, away from the house, and not onto anything that will be damaged by weight or salt. Pushing snow off the outer edge, away from the wall, keeps meltwater away from the house and the door threshold. Avoid dumping it onto shrubs below the railing, onto window wells, or into the path to the stairs. FEMA's guidance for roof snow, to keep removed snow away from exits, downspouts and vents, applies here too.

Do not pile snow from the driveway or walks onto the deck, and do not leave shoveled snow in a heap in one corner of it. A concentrated pile is exactly the kind of uneven load that deck design tables do not assume. Our guide to where to pile snow covers the rest of the property.

Can you use a snow blower on a deck?

Check with your deck maker first. The Trex winter guidance we read recommends a broom for light snow and a plastic shovel for deeper snow, and says nothing in favor of machines. A blower is heavy, its housing rides on the boards, and on a raised deck its chute throws snow somewhere hard to control, so for most decks hand tools are the safer choice. If you are weighing machines for the rest of the property, see plowing or snow blowing.

Shoveling safely matters for you as well as the boards. OSHA's advice is to scoop small amounts, push snow rather than lift it where possible, and lift with your legs without twisting. On a raised deck, take extra care near the edges and stairs.

How do you get a deck ready before winter?

Trex suggests doing preventive work after the leaves fall but before the snow: sweep off leaves and debris, clean the deck, and cover any furniture you plan to leave out. Clearing debris now means the first snow lands on a clean surface. While you are out there, note which parts of the deck sit under a roof edge, where downspouts discharge nearby, and which route people actually walk.

A fall cleanup can include clearing leaves from decks, steps and the beds around them before the first lasting snow. If trees overhang the deck, pruning back limbs that drop snow and ice onto it is worth doing while they are dormant; see our dormant pruning page.

Do we clear decks?

Yes, where access requires it. Our residential snow removal arrangements cover driveways, walkways, steps, landings and decks where they are part of the route people use, with ice management on the surfaces where refreeze is a real risk. We agree which surfaces are included, and how they are cleared, before the season. See our full snow and 24-hour storm services, and the rest of our Montana Winter Property Guide.

To add a deck and back steps to your winter route, call (406) 215-7319 or request a free estimate.

More resources