Here's a number that surprises most Cary homeowners: the average composite deck in our climate loses about 15 percent of its structural integrity over a decade if you skip the spring inspection and fall cleanup. Not from the material failing, but from moisture getting trapped where it shouldn't. Composite decking is tough, but it isn't maintenance free. It's maintenance different. You skip the annual sealing, but you cannot skip the seasonal attention. This checklist walks you through exactly what to do each quarter, so your deck still looks new when you're ready to sell in 2036.
Spring Prep: Cleaning and Inspection After Illinois Winters
March and April in Cary are brutal on a deck. Freeze thaw cycles, road salt that gets kicked up from the street, and the weight of snow sitting on the same spots for weeks. By the time the crocuses pop, your deck has taken a beating.
Start with a visual inspection before you clean. Walk every board. Look for popped screws or nails, which are common after the ground shifts during thaw. Check the ledger board where the deck attaches to your house, that seam is the most common failure point. Push on railings near the stairs. If anything wobbles, mark it and get it fixed before you put furniture back out.
For cleaning, skip the pressure washer on full blast. Composite decking manufacturers recommend keeping the nozzle at least 12 inches from the surface, and using a fan tip, not a zero degree jet. High pressure forces water between the boards and into the substructure, where it sits and accelerates rot in the framing underneath. Use a deck specific cleaner and a soft bristle brush. Rinse thoroughly with a garden hose. In Cary, where our humidity can hit 85 percent by late May, any soap residue left behind becomes a breeding ground for mildew.
If you notice heavy staining or mold that a brush won't lift, that is a sign your composite is a lower grade material or has been neglected longer than a single season. Burns Carpentry handles composite Deck Repairs for situations like this, but for most homeowners, a simple cleaning with warm water and a mild detergent is all you need. Do not use bleach. It breaks down the protective cap layer on quality composites and voids the manufacturer warranty.
Summer Care: UV Protection and High Traffic Zones
Illinois summers are the high season for decks, and also the high stress season. Direct sunlight, afternoon thunderstorms that roll in fast, and constant foot traffic from barbecues and kids. Composite decking handles UV better than wood, but it still fades over time. The difference is that fading happens evenly across the surface instead of in patches.
Your main job in summer is keeping debris off the surface. A dry leaf that sits in a corner for two weeks during a humid July will leave a tannin stain that is nearly impossible to remove. Sweep once a week. Move your grill and furniture every couple of weeks to prevent uneven exposure and allow the deck to dry underneath. Speaking of grills, put a mat under yours. Grease splatter is acidic and will dull the finish on composite boards if left to sit.
Watch the high traffic zones: the path from the door to the grill, the top of the stairs, and the area directly in front of the seating. These spots take the most abrasion. If you see the surface starting to look fuzzy or worn, that means the protective cap layer is thinning. That is rare with quality composites but happens fast with cheap materials. Burns Carpentry uses premium composite brands specifically chosen for Midwest climates, with cap layers rated for 25 to 30 years of sun exposure.
One thing most people don't think about: furniture feet. Rubber or metal feet that sit wet can discolor composite in a single season. Use furniture pads or coasters under chair and table legs. It looks minor, but it prevents those permanent dark circles that make a deck look old before its time.
Fall Readiness: Leaf Debris and Moisture Management
Fall is where the real damage happens, and most people don't realize it until spring. Leaves pile up, get wet, and stay wet for weeks. Underneath that soggy layer, moisture gets trapped against the deck boards and in the gaps between them. Composite decking is moisture resistant, but the substructure underneath is still wood. Trapped moisture speeds up rot in the joists and beams, and that is an expensive repair.
Make it a habit to clear leaves at least once a week during peak fall, especially after heavy rain or wind. Pay extra attention to the corners where the deck meets the house, and around the base of any posts. Blow or sweep debris away from the gaps between boards. If leaves are wedged between the boards, pull them out by hand. A leaf blower on high setting works for surface debris but won't clear what is packed in the gaps.
Check the gutters above your deck too. In Cary, we get about 35 inches of rain annually, and a clogged gutter dumps that water directly onto your deck in a concentrated stream. Over a season, that constant drip can erode the ground underneath the deck supports, causing settling. Clean your gutters before the leaves drop, and again after the last leaf falls.
If your deck has a roof or pergola over it, inspect that structure now. Burns Carpentry builds custom pergolas that hold up well to Illinois weather, but even the best built structure needs a check on fasteners and sealants every fall. Tighten any loose bolts and reapply sealant around mounting brackets if you see cracking.
Winter Storage: Furniture, Grills, and Snow Removal Tips
Here is where most people make their biggest mistake: they leave furniture and grills out all winter. Even heavy duty outdoor furniture degrades when buried in snow for three months. The plasticizers leach out, the fabric fades, and the metal rusts. Store everything in a shed, garage, or basement once the forecast shows sustained temperatures below freezing. If you cannot store it, at least cover it with a breathable waterproof cover, and lift it off the deck surface with blocks or pavers so air circulates underneath.
Snow removal on Composite Decks requires a soft touch. Use a plastic shovel, never a metal one. Metal gouges the surface and those scratches collect dirt and moisture, making the damage worse over time. Do not use rock salt or ice melt products containing calcium chloride. The chemicals react with the composite polymers and cause discoloration and surface cracking. Use sand for traction, or a product specifically labeled safe for composite decking. If you hire a snow removal service in Cary, tell them explicitly that you have composite decking and to use a plastic shovel only.
One winter maintenance task that nobody talks about: check the deck for ice dams. If your deck is attached to a roof line, melting snow can refreeze at the edge of the deck and trap water against the ledger board. That water finds its way into the house wall. If you see ice buildup at the seam between deck and house, knock it off gently with a rubber mallet or pour warm water over it to melt it. Do not chip at it with a metal tool.
Year Round Quick Checks to Extend Deck Life
Beyond the seasonal deep work, there are four quick checks you can do in under five minutes every month. These catch small problems before they become big ones.
Fastener check: Run your hand over the surface of the boards. If you feel a screw head poking up, tighten it or replace it. A raised screw head snags feet and catches debris.
Gap inspection: Look at the spacing between boards. If gaps are wider than they were when the deck was built, the substructure may be shifting. That warrants a professional look. Burns Carpentry offers free estimates for deck inspections in Cary, and catching a framing issue early saves thousands.
Rail stability test: Lean on the railing at the top of the stairs with moderate pressure. If it flexes more than a quarter inch, the posts or brackets need attention. Loose railings are the number one safety issue on older decks.
Mold and mildew spot check: In Cary's humid summers, you can see mildew forming in shaded corners within two weeks. A quick spray with a composite safe cleaner and a scrub with a soft brush stops it from spreading.
Frequently Asked Questions
Do I need to seal composite decking every year?
No. That is the main advantage of composite decking over wood. Quality composite boards have a protective cap layer that resists moisture and UV damage. You never need to stain or seal them. If your composite deck is fading or showing wear, it is likely a lower grade material or the cap layer has been damaged by improper cleaning.
How often should I clean my composite deck in Cary?
Sweep weekly during spring, summer, and fall to prevent debris buildup. Do a deep clean with a deck specific cleaner and soft brush once in spring and once in fall. In winter, just keep snow cleared with a plastic shovel and avoid chemical ice melt.
Can I use a pressure washer on my composite deck?
Yes, but carefully. Keep the nozzle at least 12 inches from the surface and use a wide fan tip. Never use a zero degree jet or hold the wand too close. High pressure can delaminate the cap layer and force water into the substructure. A garden hose with a spray nozzle works fine for most cleaning.
What is the most common mistake people make with composite decks?
Leaving furniture and grills on the deck all winter. The weight traps moisture underneath, and the temperature changes cause the composite to expand and contract differently under the furniture. This leads to uneven surfaces and permanent indentation. Store everything off the deck during the cold months.
If your deck survived another Cary winter but is starting to show its age, or if you are ready to upgrade to composite and never deal with sealing again, Burns Carpentry handles the whole process from design to final inspection. We build composite decks specifically for Illinois weather, with proper substructure and drainage planning that most contractors skip. Give us a call for a free estimate. We will tell you straight up whether your current deck can be repaired or if a new build makes more sense.
