Building a deck in Missouri isn’t just about picking a design that looks good on Pinterest. It’s about making sure that design holds up when the sun is blazing in August, the snow piles up in January, and heavy rains hit in the spring.
At Morganco, we often hear homeowners say, “We just want something that lasts—and doesn’t turn into a maintenance nightmare.” That’s completely fair. A deck is an investment, and in a place like Missouri where the weather can swing from one extreme to another, it’s essential to plan accordingly.
This guide will walk you through exactly what to consider—from the best materials to drainage, structural integrity, and maintenance strategies—so your deck isn’t just beautiful on day one, but still going strong 10 or even 20 years later.
Whether you're thinking about adding a deck for extra outdoor living space or replacing an old one that's past its prime, the choices you make today will directly impact how well your deck holds up tomorrow. Let’s break down what matters most.
Understanding Missouri’s Climate
If you’ve lived in Missouri for more than one season, you already know: the weather here keeps you on your toes. Designing a deck for this kind of environment means preparing for:
Read more about the Missouri climate here
Hot, Humid Summers (June through August)
Missouri summers bring long stretches of heat and humidity, especially from June through August. Prolonged exposure to UV rays can dry out and fade untreated wood, while humid conditions create a breeding ground for mildew and mold—especially in shaded areas. Choosing the wrong material or skipping UV protection can lead to a deck that looks weathered within a single season.
Cold Winters and Freeze–Thaw Cycles (December through February)
Come winter—from December through February—Missouri shifts hard in the other direction. Subfreezing temps, snow, and ice buildup can take a serious toll. Even more damaging are the freeze–thaw cycles, which cause materials to expand and contract. If your deck’s foundation isn’t set deep enough or the boards aren’t installed with proper spacing, cracks and warping are inevitable.
Heavy Rain and Flooding (March through May)
Spring rains don’t hold back in Missouri. Between March and May, storms can bring intense rainfall that lasts for days. Poor drainage can turn your beautiful deck into a soggy, moldy mess. When water pools or seeps into unsealed wood, rot sets in fast. And let’s not forget the risk of hidden water damage in joists or framing underneath.
Wind and Storm Damage (Year-Round, Especially April through June)
Thunderstorms, hail, and high winds are a year-round risk, with peak storm activity from April to June. If railings, fasteners, or the substructure aren't designed to take that kind of impact, you may be looking at repairs—or worse, a full rebuild—after a strong storm rolls through.
When we build decks at Morganco, we’re not just focused on aesthetics. We think through how the weather will interact with every single board, fastener, and joint—because that’s the difference between a deck you enjoy for decades and one you replace in five years.
When’s the Best Time to Build Your Deck in Missouri?
Timing your build isn’t just a matter of convenience—it directly impacts how well your deck turns out and how long it lasts.
Best Months to Build: April to Early June, and September to October
Spring (April–early June) is ideal because the ground has thawed, moisture levels are manageable, and contractors tend to have better availability before the summer rush. Materials like wood and composite also install better in mild weather, reducing the chance of warping or improper curing.
Fall (September–October) is another great window. The intense heat has passed, humidity drops, and your deck has time to settle and cure before facing winter.
Avoid the peak of summer (July–August) when heat and humidity can make installation more difficult and unpleasant. Likewise, winter (November–February) is risky for footing work due to frozen ground and unpredictable weather delays.
Building during the right season sets the stage for better performance. It gives sealants time to cure properly, allows for better material handling, and often reduces labor costs tied to weather disruptions.
Choosing the Right Materials for Missouri Weather
Not all decking materials are created equal—especially when you’re building in a state that sees everything from snowstorms to sweltering humidity. Here’s what we recommend, depending on your budget, lifestyle, and how much maintenance you’re willing to do.
1. Composite Decking
If you’re looking for a low-maintenance option that holds up to everything Missouri throws at it, composite decking is worth the investment.
Why it works: Composite boards are made from a mix of wood fibers and plastic, making them resistant to rot, mold, warping, and insect damage. They’re also UV-stable, which means less fading and cracking under Missouri’s summer sun.
Best for: Homeowners who want long-term durability with minimal upkeep.
Considerations: Higher upfront cost, but much lower maintenance over time. Occasional washing is all that’s needed—no staining, sealing, or sanding.
2. Pressure-Treated Lumber
The most common deck material in the Midwest, and for good reason—it’s affordable and treated to resist decay.
Why it works: Pressure-treated wood is chemically enhanced to resist rot, mold, and insects. It’s widely available and cost-effective.
Best for: Budget-conscious homeowners willing to do regular upkeep.
Considerations: Needs to be sealed or stained every 1–2 years. Without consistent maintenance, it can crack, splinter, or warp in Missouri’s wet–dry cycle.
3. Cedar and Redwood
Naturally beautiful and decay-resistant, these woods offer a classic look with solid performance.
Why it works: Cedar and redwood have natural oils that make them resistant to rot and insects. They’re also more dimensionally stable than pressure-treated pine.
Best for: Homeowners who love the look of real wood and don’t mind a bit of seasonal maintenance.
Considerations: Still requires sealing to prevent weathering and graying. Missouri’s high humidity can lead to surface mold if not cleaned regularly.
4. Ipe and Other Tropical Hardwoods
These exotic hardwoods are among the toughest, most weather-resistant decking options available.
Why it works: Ipe, cumaru, and similar hardwoods are incredibly dense, naturally rot-resistant, and can last 40+ years with proper care.
Best for: High-end builds where longevity and performance are top priorities.
Considerations: Requires special tools to install and regular oiling to maintain color. Without treatment, it will weather to a silver patina. Also, more expensive upfront.
Check out our material selections here to learn more about the materials you like for your deck!
Bottom Line:
In Missouri, where your deck needs to fight off heat, cold, moisture, and time, composite decking often delivers the best balance of performance and low upkeep. But if you love the feel of real wood and don’t mind regular care, high-quality lumber can serve you well—especially when installed and maintained properly.
Moisture Management & Drainage Design
Water is a deck’s worst enemy. And in Missouri, with heavy rainfall and high humidity from spring through late summer, effective moisture control isn’t optional—it’s essential.
1. Proper Deck Slope and Spacing
Every deck board should be installed with a slight gap—typically ⅛" to ¼"—to allow water to drain through, not sit on the surface. This spacing also helps with air circulation to dry out the boards faster after a storm.
Slope away from the house to prevent water from collecting near the ledger board, which is a common failure point for rot and leaks.
2. Joist Flashing and Drainage Systems
Moisture doesn’t just hurt your deck surface—it can silently rot the framing underneath.
Joist tape (butyl or rubber-based) is a simple upgrade that protects wood framing from water trapped between deck boards.
If your deck is two stories or built above a walkout, consider installing an under-deck drainage system to route water away from the structure entirely. It also allows you to use the space underneath for storage or seating.
3. Sealing and Waterproofing
Even pressure-treated wood benefits from a quality sealant. For Missouri decks, choose one with:
Water repellents to prevent absorption.
Mildewcides to fight surface mold.
UV blockers to slow fading and surface breakdown.
Sealants should be reapplied every 1–3 years depending on foot traffic, sun exposure, and deck material.
Structural Integrity for Missouri Conditions
A good-looking deck means nothing if it can’t stand up to time and weather. And in a region like Missouri—with temperature swings, shifting soils, and storm winds—your deck needs a rock-solid backbone.
Read more about deck’s structural integrity in Missouri here
1. Footings Below Frost Line
In Missouri, frost depth is generally 36" to 42", depending on your location. Footings must go below that line to prevent frost heave, which can cause the entire deck to lift, tilt, or crack over time.
Concrete piers or sonotubes are standard for proper load distribution.
Avoid floating decks unless they’re built specifically for ground-level, low-load use.
2. Ledger Board and House Attachment
The ledger board is where the deck connects to the house—and it's a common point of failure if not installed correctly.
Use lag bolts or structural screws, not nails.
Install flashing above and behind the ledger to prevent water intrusion and rot at the connection point.
3. Quality Fasteners and Hardware
Missouri’s mix of rain and humidity means rust is a real concern. Always use:
Stainless steel or hot-dipped galvanized fasteners
Coated hangers and connectors for joists and beams
These components resist corrosion far better than standard nails or screws and provide essential shear strength in high-wind scenarios.
4. Reinforced Railings and Load Support
Deck railings must meet code for both height and strength. In Missouri, that usually means:
36" height minimum
Railings must withstand 200 lbs of force at any point
Use reinforced posts, blocking, and proper brackets to ensure they stay secure over time—especially if your deck is elevated.
Permits & Local Building Codes
Missouri doesn’t have a single statewide building code—local municipalities handle code enforcement. But most cities and counties follow some version of the International Residential Code (IRC) with local amendments.
That means before you build, it’s critical to understand the requirements in your specific area.
Click here to know more about the local building codes for decks in Missouri
1. Permitting Requirements
Most Missouri jurisdictions require a permit for:
Decks more than 30" above grade
Decks attached to the home
Any deck with electrical, gas lines, or permanent roofing
At Morganco, we handle permitting and inspections for our clients to ensure a stress-free process, but if you're doing it yourself, always call your local building department before breaking ground.
2. Key Code Factors to Watch
Footing Depth: Must extend below frost line (typically 36"–42").
Railing Height: At least 36" high if the deck is 30" or more above grade.
Stair Riser Height: Max 7¾", with a consistent rise.
Ledger Board Attachment: Must use structural screws or bolts—no nails—and proper flashing to prevent water damage.
Failure to follow code doesn’t just risk fines. It also puts your safety at risk and can void your homeowner’s insurance in the event of an accident.
Maintenance Plan for Long‑Term
Even the best-built deck needs regular attention to stay safe and attractive—especially with Missouri’s constant cycle of heat, rain, freezing, and thawing. A simple maintenance plan can dramatically extend your deck’s lifespan and help you catch small issues before they turn into costly repairs.
1. Annual Cleaning
Use a deck-safe cleaner (never bleach) to remove dirt, mildew, pollen, and stains.
Power wash only when necessary, and always on a low setting. High pressure can gouge wood or damage composite surfaces.
2. Resealing and Restaining
For pressure-treated or natural wood decks, apply a water-repellent sealant every 12 to 24 months.
If your deck has a colored stain, plan to refresh it every 2 to 3 years to maintain its appearance and protection.
Composite decks don’t need sealing but benefit from occasional washing and UV-resistant sprays to keep them looking new.
3. Inspect for Damage
Twice a year (typically spring and fall), inspect for soft spots, warped boards, loose fasteners, and signs of rot or mildew.
Pay close attention to the ledger board, footings, and areas near stair connections—these are common problem zones.
Tighten loose railings or hardware immediately to keep your deck safe and code-compliant.
4. Seasonal Preparation
In fall, sweep off leaves and debris regularly to prevent staining and moisture buildup.
In winter, avoid metal shovels or harsh salts—they can damage both wood and composite finishes. Use a plastic shovel and a calcium-based ice melt instead.
In spring, clean out under-deck areas, check for water drainage issues, and take care of any minor repairs before summer entertaining begins.
5. Call Your Contractor or Design-Build Team When in Doubt
Not every issue is visible, and not every repair should be DIY. If you notice sagging boards, moisture pooling, shifting stairs, or just something that “feels off,” don’t wait. Call your contractor or design-build professional to take a look. A quick visit now could save you thousands down the road—and help ensure your deck stays safe, beautiful, and built to last.
Smart Add‑Ons for Longevity
If you're already putting in the time and investment to build a durable deck, it makes sense to include upgrades that extend its life and make it more functional year-round. These enhancements do more than add luxury—they protect your deck from Missouri’s extreme climate.
1. Shade Solutions
Installing pergolas, shade sails, or retractable awnings can significantly reduce sun damage. By cutting down on direct UV exposure—especially during July and August—you help prevent surface cracking, fading, and unnecessary wear on both furniture and decking materials.
2. Under-Deck Drainage Systems
If your deck is elevated, adding an under-deck drainage system is a smart way to protect the structure and reclaim usable space. These systems channel rainwater away from your framing and foundation, helping to prevent long-term rot while creating a dry, shaded area below—perfect for extra storage or even a patio.
3. Built-In Lighting
Low-voltage or LED deck lighting isn’t just for aesthetics—it’s safer and more weatherproof than plug-in options. Built-in lights enhance visibility at night, protect wiring from rain and pests, and improve curb appeal without compromising durability.
4. Covered Grill Stations or Outdoor Kitchens
For families who entertain regularly, a covered cooking area is a game-changer. It protects your deck surface from grease splatter, food spills, and unexpected rain. Plus, it extends your outdoor season by creating a functional space that works even when the weather doesn’t cooperate.
5. Integrated Gutter Systems
If your deck is attached to your home, integrating it into your existing gutter system is a no-brainer. Proper drainage helps divert water away from ledger boards, footings, and the surrounding soil, reducing erosion and extending the life of your structural supports.
Frequently Asked Questions
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It can—but only if the wrong material is used or it’s installed poorly. Missouri’s summer heat (especially in July and August) causes expansion and contraction in wood. Composite decking handles this better thanks to its stability and low moisture absorption. If you go with natural wood, make sure it’s sealed properly and installed with adequate spacing for ventilation and movement. Also, avoid dark-colored boards in full sun—they absorb more heat and can dry out faster.
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That depends on the material. Composite requires little more than seasonal cleaning. Pressure-treated wood, cedar, and redwood need a bit more love—cleaning once or twice a year, sealing every 1–2 years, and occasional restaining. The key is consistency. Skipping maintenance may not show right away, but it will catch up with you in the form of rot, fading, or loose boards. A good rule of thumb: treat your deck like you treat your car—it’ll last longer with regular attention.
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In most cases, yes—especially in a climate like Missouri. While the upfront cost is higher, you save on maintenance, repairs, and replacements over time. Composite won’t splinter, rot, or fade like untreated wood, and you won’t need to spend weekends staining or sealing it every couple of years. For busy families who want something durable and low-maintenance, it often pays off in peace of mind.
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Technically, yes—but it’s not ideal. Cold weather makes excavation and concrete work more difficult, and some materials (especially wood) can behave unpredictably in freezing temperatures. Moisture in the ground or sudden weather shifts can also cause delays. If winter is your only option, work with an experienced contractor who knows how to manage frost depth and cold-weather construction. That said, early spring or early fall is almost always better for a smoother build.
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Often, yes. If the framing is in good condition and up to code, you can sometimes replace the decking surface and railings without rebuilding the entire structure. This is especially common when switching from wood to composite. However, we always recommend a professional inspection—especially to check the ledger board, footings, and fasteners. These hidden areas can be the source of costly problems if left unchecked.
Missouri’s weather doesn’t have to be your deck’s downfall. With the right materials, construction practices, and a simple maintenance plan, you can enjoy a beautiful, long-lasting outdoor space that adds real value to your home.
At Morganco, we’ve helped hundreds of Missouri homeowners build decks that hold up year after year—through sun, snow, and storms. If you’re ready to start planning your deck, we’d love to walk you through your options and make sure your investment lasts.
Reach out today for a no-pressure consultation, and let’s design a deck that’s built for Missouri—and built for life!