Things You Should Never Do to Your Deck: Common Mistakes That Cause Lasting Damage

Your deck is one of the hardest-working parts of your home. It handles foot traffic, furniture, weather extremes, and years of sun exposure without complaint. But even the best-built outdoor living space won't last if it's subjected to common care mistakes that many homeowners don't realize they're making.

After more than 30 years of building and repairing decks across Colorado's Front Range, our team at Griffin Decks & Covers has seen the same preventable problems come up again and again. Some of these mistakes seem harmless at first. Others look like they're actually helping. But over time, they all lead to the same result: a deck that ages faster, performs worse, and needs expensive repairs sooner than it should.

This guide covers the things you should absolutely avoid doing to your deck—whether it's built from pressure-treated wood, cedar, or capped composite. We'll also share what to do instead so your outdoor space stays safe, beautiful, and functional for years to come.

Never Sand Your Deck with an Orbital Sander

It sounds counterintuitive, right? Sanding seems like a responsible thing to do when your deck looks rough or weathered. But aggressive sanding—especially with an orbital sander—does more harm than good.

Here's why: an orbital sander creates an unnaturally smooth surface on wood deck boards. While that might feel nice underfoot, it actually prevents stains and sealers from absorbing properly. The finish won't bond to the wood, which means it'll peel, flake, and fail within months.

Orbital sanders also tend to leave swirl marks and uneven patches, particularly on softer woods like cedar and pressure-treated pine. If those marks get sealed over, they become permanent visual defects.

What to Do Instead

• Choose the right stain from the start. A high-quality penetrating stain won't peel and won't require sanding before reapplication. It soaks into the wood grain rather than sitting on top of it.
• If light sanding is necessary, use a pole sander with medium-grit paper and move in the direction of the wood grain. This preserves the texture stains need to grip.
• For composite decking, sanding should be avoided entirely. Composite boards have a protective cap that sanding will destroy, voiding your warranty and exposing the inner material to moisture.

If your deck boards are damaged beyond what stain can fix, it may be time to consider professional deck repair services rather than aggressive sanding that creates new problems.

Never Place a Fire Pit Directly on Your Deck

Fire pits are a centerpiece of backyard gatherings, especially during Colorado's cool evenings. But placing one directly on your deck is one of the most dangerous things you can do—and it's a mistake we see far too often.

The problem goes deeper than the obvious fire risk. Even if you use a fire pit "safely" on a raised stand, here's what actually happens:

• Radiant heat builds up underneath and around the pit, warping and discoloring deck boards over time—even boards rated for heat resistance.
• Embers and sparks can settle into the gaps between deck boards, smoldering against the joist structure below where you can't see them.
• Smoke and soot residue stain finishes and accelerate surface degradation, especially on lighter-colored composite materials.
• Local fire codes in many Front Range municipalities prohibit open-flame fire pits on combustible deck surfaces altogether.

A Safer Approach

If you want a fire feature as part of your outdoor living space, consider designing a dedicated stone or concrete pad adjacent to your deck. You can also use a natural gas fire table that's rated for use on decking, combined with an approved heat-resistant barrier beneath it.

Planning your fire area from the beginning is ideal. When we design custom decks, we often incorporate separate zones for cooking and fire features that keep the deck itself protected while giving you the full outdoor experience.

Never Clean Your Deck with Household Bleach

Bleach is a powerhouse cleaner for bathrooms and kitchens, but it's terrible for your deck. This is one of the most common mistakes homeowners make when trying to remove mildew, algae, or general grime from their outdoor surfaces.

Here's what chlorine bleach does to deck materials:

• On wood: It breaks down lignin, the natural compound that holds wood fibers together. This weakens the surface layer and causes graying, discoloration, and raised grain.
• On composite: Concentrated bleach can strip the color from capped composite boards, leaving permanent light spots and streaks that become glaringly visible in sunlight.
• On surrounding landscaping: Bleach runoff kills grass, flowers, and plantings near your deck. It also corrodes metal fasteners and flashing over time.

Better Cleaning Alternatives

• Oxygen-based cleaners (sodium percarbonate) effectively remove mildew and algae without damaging wood fibers or composite caps.
• Manufacturer-approved cleaners for composite brands like Deckorators are specifically formulated to clean without voiding your warranty.
• A simple mix of dish soap and warm water with a soft-bristle brush handles most routine cleaning.
• Rinse thoroughly after any cleaner application. Residue left on the surface attracts dirt and can create slippery patches.

Never Use a Pressure Washer at Full Force

Pressure washing feels productive. You can watch years of grime disappear in minutes. But at full force—typically 2,500 to 3,000+ PSI—a pressure washer does serious damage to deck surfaces that you won't notice right away.

High-pressure water blasts cut into wood grain, creating fuzzy, splintered surfaces. It pushes water deep into the board, raising moisture content well above safe levels. And on composite decking, it can strip the protective capping layer right off.

The damage often doesn't show up until weeks later when the wood dries unevenly, boards cup and twist, and the newly exposed grain absorbs dirt faster than before.

How to Pressure Wash Correctly

• Keep pressure below 1,500 PSI for wood decks and below 1,300 PSI for composite.
• Use a fan-tip nozzle (40-degree or wider), never a zero-degree tip.
• Maintain at least 12 inches between the nozzle and the deck surface.
• Move in the direction of the wood grain, not against it or in circles.
• Work in consistent, overlapping passes to avoid striping.

When in doubt, a garden hose with a spray attachment and a quality deck cleaner will do the job without the risk.

Never Ignore Loose Railings or Unstable Stairs

A wobbly railing or a staircase that shifts when you step on it might seem like a minor annoyance. But it's actually a safety hazard that gets worse quickly—especially through Colorado's freeze-thaw cycles, which loosen fasteners and shift post connections every winter.

Railing failure is one of the leading causes of deck-related injuries. When a post pulls away from the framing, the entire railing section can collapse under the weight of someone leaning against it. For elevated decks, that's a potentially serious fall.

Warning Signs to Watch For

• Any visible movement when you push against a railing post
• Gaps opening between the post base and the deck surface
• Rust stains around railing hardware or bolts
• Stair stringers that creak, flex, or feel uneven underfoot
• Tread boards that are cracked, split, or pulling away from fasteners

Don't wait to address these issues. Professional deck railing inspection and reinforcement can restore safety before a small problem becomes a dangerous one. And if your deck stairs are showing their age, a rebuild with proper stringer support and code-compliant dimensions makes a real difference in both safety and curb appeal.

Never Neglect Water Drainage and Moisture Management

Water is the single biggest threat to any deck's long-term survival. In Colorado, that threat is amplified by snowmelt, sudden summer storms, and the freeze-thaw cycles that repeat dozens of times each winter.

Many homeowners focus on what their deck looks like from above and completely forget about what's happening underneath. Standing water around footings, clogged drainage paths, and poor ledger flashing are invisible problems that cause very visible failures: rot, mold, structural sag, and fastener corrosion.

Critical Water Management Mistakes to Avoid

• Allowing leaves and debris to accumulate between boards and under the deck structure. This traps moisture and blocks airflow, creating ideal conditions for rot.
• Directing downspouts toward deck footings. Water pooling around post bases accelerates decay and can compromise footing integrity.
• Skipping ledger flashing inspection. The ledger board connection to your home is the most vulnerable point for water intrusion. Failed flashing leads to interior water damage and structural rot.
• Not grading the ground beneath your deck. The soil should slope away from your home's foundation to prevent standing water under the structure.

For elevated decks, an under-deck drainage system is one of the smartest investments you can make. These systems capture water that falls through the upper deck and channel it away from the substructure, creating dry, usable space below while protecting your joists, beams, and footings from moisture damage.

Never Overlook Deck Lighting and Visibility

A dark deck is a dangerous deck. Trips, falls, and missteps happen most often in the evening when stairs, level changes, and railing edges become invisible. Yet lighting is one of the most overlooked elements in deck design and maintenance.

Beyond safety, proper lighting dramatically extends how long you can comfortably use your outdoor space each day. It also enhances the visual appeal of your home from the street and highlights architectural features you've invested in.

Where Deck Lighting Matters Most

• Stair treads and risers: Step lights or riser-mounted LEDs make every step visible, even on moonless nights.
• Railing posts and caps: Post-cap lights provide ambient illumination without glare.
• Perimeter and transition areas: Where your deck meets the yard, a patio, or a walkway, low-level lighting prevents missteps at grade changes.
• Overhead and pergola lighting: String lights or recessed fixtures in a pergola or patio cover create an inviting atmosphere for evening entertaining.

The best time to plan deck lighting is during the design phase, when wiring can be integrated into the structure itself. But retrofitting is also possible on existing decks—especially with low-voltage LED systems that don't require major electrical work.

Never Leave Your Deck Fully Exposed to Colorado's Sun

Colorado's Front Range gets over 300 days of sunshine per year. That's great for your mood—and terrible for unprotected deck materials. Intense UV exposure fades finishes, dries out wood, accelerates composite color shift, and makes your deck uncomfortably hot during summer afternoons.

A deck without any shade or coverage limits when you can actually use it. On south-facing homes especially, surface temperatures can exceed 150°F in July, making barefoot use impossible and shortening the lifespan of every material on the structure.

How to Protect Your Deck from UV Damage

• Install a pergola to provide filtered shade that reduces surface heat while maintaining airflow and open sightlines. Pergola installation is one of the most popular additions we build for Front Range homeowners.
• Add a patio cover for full shade and weather protection. A well-designed patio cover extends your deck's usability into rain and snow, making it a true four-season space.
• Consider a lean-to cover that attaches directly to your home's exterior wall, providing overhead protection with a clean, integrated look. Lean-to covers work especially well for narrower decks or homes with limited yard depth.
• Apply UV-protective finishes to wood decks annually, and clean composite surfaces regularly to prevent UV-related color changes.

Never Attempt Structural Modifications Without Professional Help

Weekend projects are rewarding. Replacing a few deck boards, adding a planter box, or installing new post-cap lights—these are reasonable DIY tasks. But cutting into joists, modifying the ledger connection, adding a new staircase, or extending the deck footprint? Those are structural changes that require engineering knowledge, code compliance, and often a building permit.

Here's what can go wrong with DIY structural modifications:

• Undersized joists or beams that can't support the added load, leading to deflection and eventual collapse.
• Improper post-to-beam connections that fail under lateral loads, especially during high winds common along the Front Range.
• Code violations that create liability issues, affect your homeowner's insurance, and complicate a future home sale.
• Permit problems when modifications are discovered during inspection—resulting in tear-out and rebuild requirements.

Each municipality along Colorado's Front Range—Littleton, Parker, Castle Rock, Centennial, Aurora—has specific permitting and inspection requirements for deck construction. Getting these right from the start saves time, money, and stress. Our team at Griffin Decks & Covers handles full design, engineering, permitting, and construction for projects of every scope, so you can be confident the work meets both your vision and your local building codes.

Never Skip Seasonal Inspections—Especially After Winter

Colorado winters are tough on outdoor structures. Freeze-thaw cycling pushes fasteners out, cracks wood fibers, and shifts footings. Heavy snow loads stress connections. Ice dams form against ledger boards. And through it all, your deck sits exposed without any attention until spring arrives.

The single most important thing you can do for your deck's longevity is a thorough spring inspection after the snow melts. Here's a focused checklist:

Spring Deck Inspection Checklist

• Fasteners: Check for popped nails, backed-out screws, and corroded hardware. Replace anything that's loose or rusted.
• Board condition: Look for cracks, splits, warping, and soft spots that indicate rot. Press a screwdriver into suspect areas—if it sinks easily, the board needs replacement.
• Railing stability: Push firmly against every railing post. Any movement beyond 1/8 inch indicates a connection problem.
• Stair integrity: Walk every step and check stringer connections, tread attachment, and riser condition.
• Ledger board: Inspect the flashing where your deck connects to the house. Look for gaps, rust, and signs of water intrusion.
• Under-deck area: Clear debris, check for standing water, and examine joist and beam surfaces for mold or decay.
• Drainage: Confirm that water flows away from footings and the home's foundation.

If your inspection reveals issues you're not sure how to address, Griffin Decks & Covers offers free professional inspections for homeowners across the Front Range. We'll assess the condition of your structure and recommend the most effective path forward—whether that's targeted deck repair or a longer-term maintenance plan.

Never Choose Deck Materials Without Considering Your Climate

Not every decking material performs well in every climate, and Colorado's conditions are more demanding than most. The combination of high altitude UV radiation, extreme temperature swings (from -10°F to 95°F), low humidity, and regular freeze-thaw cycling creates a unique stress environment that certain materials simply aren't built for.

Material Considerations for Colorado Decks

• Pressure-treated wood is a solid structural choice for framing, but it requires consistent sealing and staining to prevent UV degradation and moisture absorption. Without annual maintenance, pressure-treated boards can crack, warp, and gray within two to three years in Colorado's sun.
• Cedar offers natural beauty and rot resistance, but it's softer than many homeowners expect. It needs UV-protective coating every one to two years and is prone to surface checking in low-humidity environments.
• Capped composite is the most popular choice for Colorado decking surfaces because it resists UV fading, moisture absorption, and insect damage. It doesn't need staining or sealing. However, the substructure still requires attention—composite boards are only as good as the framing beneath them.
• Aluminum framing is increasingly used beneath composite decking to eliminate rot risk entirely. It's especially valuable for elevated decks and structures with under-deck systems where moisture exposure is constant.

When you work with an experienced builder who understands Front Range conditions, material selection becomes a strategic decision—not a guess. Our team walks through every option with you during the design phase of every custom deck project.

Never Use Rock Salt or Chemical De-Icers on Your Deck

When ice coats your deck stairs in January, your first instinct might be to grab the same bag of rock salt you use on your driveway. Resist that urge.

Rock salt (sodium chloride) and many chemical de-icers are corrosive to both wood and metal. On a deck, they cause:

• Accelerated fastener corrosion, weakening the connections that hold your deck together.
• Surface pitting and discoloration on both wood and composite boards.
• Damage to aluminum and steel railing components, including handrails, balusters, and post hardware.
• Residue buildup that becomes a slippery film when temperatures rise above freezing.

Safe Ice Removal for Decks

• Use calcium magnesium acetate (CMA), which is less corrosive and safer for most deck materials.
• Spread clean sand or kitty litter for traction without chemical risk.
• Shovel snow promptly with a plastic-blade shovel to prevent ice formation in the first place.
• Never use a metal shovel or ice scraper on deck boards—it gouges and scratches surfaces.