Suncast 138 Cu Ft Horizontal Outdoor Storage Shed Review: The Ultimate Backyard Storage Solution Tested

For years, our garage played a frustrating game of Tetris. Two adult bikes leaned precariously against a wall, threatening to topple onto the lawnmower. A tangled mess of hoses and gardening tools occupied a corner, and the recycling and trash bins took up a full parking space, forcing one of our cars into the driveway. It was a constant, low-grade source of stress—a chaotic space that made simple tasks feel like an expedition. We knew we needed a dedicated outdoor storage solution, but the thought of a towering, traditional shed that would dominate our backyard felt like overkill. We needed something spacious yet discreet, durable yet accessible. The search for that perfect balance is what led us to put the Suncast 138 Cu Ft Horizontal Outdoor Storage Shed to the test.

What to Consider Before Buying an Outdoor Storage Shed

An outdoor storage shed is more than just a box to hide your things; it’s a key solution for decluttering your life and protecting your investments. It reclaims valuable garage space, safeguards expensive equipment like lawnmowers, bikes, and generators from the elements, and organizes everything from patio cushions to pool supplies. A good shed brings order to outdoor chaos, providing a secure, weather-resistant home for items that would otherwise be exposed to rain, snow, and damaging UV rays. This not only extends the life of your gear but also enhances the safety and usability of your primary living and parking areas.

The ideal customer for this type of product is a homeowner, renter with a yard, or anyone with a patio or deck who finds their garage, basement, or living space overrun with outdoor equipment. If you’re tired of tripping over bikes, struggling to find garden tools, or leaving your lawnmower exposed to the weather, a horizontal shed is a brilliant solution. Its low-profile design is often more palatable for neighborhoods with HOA restrictions and doesn’t cast large shadows like a traditional tall shed. However, it might not be suitable for those who need a walk-in workshop, require overhead storage for long items like lumber, or have absolutely no level ground to place it on. For those needing a highly portable or temporary solution, a fabric bike tent might be a better, though less secure, alternative.

Before investing, consider these crucial points in detail:

• Dimensions & Space: First and foremost, measure your intended location. The Suncast 138 Cu Ft model has a footprint of roughly 6.6 feet wide by 4.8 feet deep. You need not only this space but also clearance in front for the doors to open and above for the lid to slide back. Ensure the location is level, as this is non-negotiable for proper assembly and function.
• Capacity/Performance: “Cubic feet” can be an abstract number. At 138 cu ft, this shed is designed for bulky items. Think about your specific needs: will it hold two large e-bikes? A zero-turn mower? Multiple large municipal waste bins? The reinforced floor is a key performance feature here, as it’s rated to handle the weight of heavy equipment that would crack the floor of a lesser shed.
• Materials & Durability: This shed uses multi-wall resin panels. Unlike wood, resin won’t rot, splinter, or require painting. Unlike metal, it won’t rust or dent easily. The UV-protected plastic is designed to resist fading and cracking under the sun, making it a low-maintenance choice for long-term outdoor exposure. This construction offers a fantastic balance of lightweight handling during assembly and robust durability for years of use.
• Ease of Use & Maintenance: The signature “Glidetop” sliding lid is the main draw for usability. It provides unparalleled top-down access, which is a game-changer when you’re trying to retrieve something from the back without unpacking everything else. Maintenance is as simple as it gets: an occasional wash with soap and water is all that’s required to keep it looking new.

While the Suncast 138 Cu Ft Horizontal Outdoor Storage Shed is an excellent choice, it’s always wise to see how it stacks up against the competition. For a broader look at all the top models, we highly recommend checking out our complete, in-depth guide:

First Impressions: Unboxing and Initial Assembly

The shed arrived in a single, very large and heavy box—definitely a two-person lift. Upon opening it, we were greeted by a neatly organized stack of gray resin panels, the floor, the lid components, and a bag of hardware. The multi-wall panels felt substantial in our hands; they weren’t flimsy or brittle but had a slight flex that suggested resilience. The texture is a subtle wood grain that looks surprisingly attractive up close. One of our first observations, echoed by many users, is the critical importance of the instruction manual. We laid everything out, did a quick parts inventory (everything was there), and took a moment to read the instructions cover-to-cover. They are primarily visual, which we found to be very clear and easy to follow. Suncast has clearly refined this process over the years. The most daunting part, before even starting, was recognizing the manual’s insistence on a perfectly level foundation. This wasn’t just a suggestion; it was presented as the key to a successful build. This initial step, preparing the ground, is where the real work begins, long before the first panel is snapped into place. You can see the detailed assembly guide and part list online to prepare ahead of time.

A Deep Dive into the Suncast Glidetop Shed’s Performance

After several weeks of use, loading it with everything from bikes to pressure washers, we’ve developed a comprehensive understanding of where the Suncast 138 Cu Ft Horizontal Outdoor Storage Shed excels and the few areas where potential buyers should be prepared. It’s more than just a plastic box; it’s a thoughtfully engineered storage system.

Assembly and Foundation: The DIY Reality

Let’s address the elephant in the room: assembly. The product is marketed for fast, tool-light setup, and for the most part, this is true—with a significant caveat. The success of your entire build hinges on the foundation. We can’t stress this enough. The shed floor itself is sturdy, but it has no structural rigidity on its own. Placing it on uneven lawn or gravel will cause the entire structure to twist, making it impossible to align the walls and doors correctly. This is the source of frustration for the user who struggled for a week with alignment; it’s almost certainly a foundation issue.

We followed the manual’s recommendation and built a simple 2×4 and plywood frame set on level pavers. This side project took a few hours and added to the overall cost, as another user noted, but it was absolutely worth it. With a solid, level base, the assembly process was incredibly smooth. The panels are designed to snap into the base and each other. We found, as one reviewer wisely suggested, that a rubber mallet is your best friend. A few firm-but-gentle taps helped seat the wall panels perfectly into the floor grooves. From starting with a level base, the entire shed was constructed in about 90 minutes with two people. The instructions were flawless. One person can hold a panel in place while the other fastens or taps it in. We believe attempting this solo, while possible for a determined and patient individual, invites frustration. The large panels can be unwieldy, and getting that initial alignment right is much easier with a second pair of hands.

Design and Accessibility: The Glidetop Advantage

The single greatest feature of this shed is its Glidetop lid. In a market full of sheds with hinged lids that are heavy to lift or simple front doors that force you to dig for items in the back, the sliding roof is a stroke of genius. The mechanism operates on rollers, and with a gentle push, the top half of the roof smoothly slides back over the bottom half. This action simultaneously opens the front doors, giving you cavernous, unimpeded access to the entire interior from both the front and the top. It feels less like opening a shed and more like revealing its contents.

This design has profound practical benefits. Storing our two large mountain bikes became a simple task of just rolling them in. For smaller items like gas cans or bags of potting soil, you can simply drop them in from the top without even bending over. When it’s time to find that one specific tool, you’re not fumbling around in the dark; the open top floods the interior with light. We were so impressed with this unique and highly functional access system. The security is also well-considered. The 3-door locking system allows a single padlock (not included) to secure the two front doors and the sliding lid simultaneously, which is a simple and effective design choice that provides peace of mind.

Capacity and Durability: A Multi-Season Workhorse

With 138 cubic feet of space, the Suncast 138 Cu Ft Horizontal Outdoor Storage Shed hits a sweet spot for capacity. It’s large enough for the big stuff but doesn’t have the massive, imposing presence of a vertical shed. We easily fit two adult mountain bikes, a 21-inch push mower, a pressure washer, and a leaf blower, with room to spare for gas cans and other small items. Several users confirm it’s perfect for two large e-bikes or even a zero-turn mower, which speaks to its impressive internal dimensions (the door opening is 42.5″ wide). The real hero here is the reinforced floor. We rolled a heavy generator across it without any signs of flex or stress. This robust flooring is what makes it suitable for storing motorcycles or riding mowers, a claim few other resin sheds in this class can make.

As for durability, the multi-wall resin construction has held up beautifully. After several intense rainstorms, we checked for leaks. The interior remained almost entirely dry. We noted one user’s comment about it not being “entirely rain-proof,” and we think this is a fair assessment. The overlapping design is highly water-resistant and will keep your items safe from 99% of weather, but in a driving, wind-blown deluge, a few drops might find their way in around the lid seam. For our purposes—storing outdoor equipment—this is perfectly acceptable. We haven’t been through a winter with it yet, but the material is rated for snow loads, and its sturdy feel gives us confidence it will handle the seasons with ease. The Made in the USA build quality is apparent, and it’s a feature that adds to our confidence in its longevity. You can explore its full specifications and weather-resistance ratings to see if it matches your climate.

What Other Users Are Saying

Across the board, the sentiment for the Suncast 138 Cu Ft Horizontal Outdoor Storage Shed is overwhelmingly positive, with a few consistent caveats that match our own experience. Many users praise it as “very easy to assemble” with “great instructions,” often citing build times of around an hour to 90 minutes. One user was particularly impressed, stating it was “surprisingly fun to build.”

However, this praise is almost always from those who either had a second person helping or who properly prepared a level base. The most prominent negative feedback comes from a user who struggled immensely with alignment while building it alone, highlighting our recommendation to tackle this as a two-person job. The most common “surprise” among reviewers was the necessity of this foundation. As one person put it, “Most people know that a shed requires a level… base; however, I did not know that… beware, you will have to buy additional supplies.” It’s a crucial point of preparation. We also saw praise for Suncast’s customer service, with one reviewer who received a wrong part having a replacement shipped free of charge and arriving within days. While a few people mentioned shipping damage to the box, the product inside was usually fine, though damage to the floor panel out of the box was noted in one case.

How Does It Compare to the Alternatives?

While the Suncast Glidetop is a fantastic unit, it exists in a competitive market. Depending on your budget, space, and security needs, one of these alternatives might be a better fit.

1. MAIZOA 2-3 Bike Storage Tent

The MAIZOA tent is a completely different approach to outdoor storage. It’s essentially a heavy-duty, waterproof fabric tent supported by poles. This is the ultimate budget and portability option. If you are a renter, need a temporary solution, or only need to store a couple of bikes from the rain, this is an excellent choice. However, it offers virtually no security against theft and lacks the rigid structure and long-term durability of the Suncast resin shed. It won’t support any weight from snow and is more susceptible to wind. Choose this if your priority is low cost and portability over security and all-season ruggedness.

2. Keter Store-It-Out Prime Outdoor Storage Shed

The Keter Store-It-Out Prime is a direct competitor, also made of durable, weather-resistant resin. Its primary difference is size and access. At roughly 30 cubic feet of capacity, it’s significantly smaller than the Suncast 138. This makes it a superior choice for tight spaces, like a small patio or alongside a house, where it’s perfect for storing garden tools, pool floats, or cushions. Its access mechanism features a hinged lid with hydraulic pistons (“Easy Lift Hinges”) and front doors. While effective, it doesn’t offer the same complete top-down access as the Glidetop. If your storage needs are modest and your space is limited, the Keter is a strong, high-quality contender.

3. Suncast 34 Cu Ft Horizontal Outdoor Storage Shed

If you like the quality and low-maintenance appeal of Suncast but find the 138 cu ft model to be overkill, this smaller 34 cu ft version is the logical choice. It’s perfectly sized to conceal two standard garbage and recycling bins, keeping your yard tidy and animals out. It’s also great for storing firewood, bags of salt, or a small collection of gardening supplies. It retains the durable resin construction of its larger sibling but features a simpler, hinged lift-top lid. This is the ideal solution for those with very specific, smaller-scale storage needs, particularly for waste bin concealment, where the giant capacity of the Glidetop model isn’t necessary.

The Final Verdict: Is the Suncast 138 Cu Ft Shed Worth It?

After extensive testing, our answer is a resounding yes. The Suncast 138 Cu Ft Horizontal Outdoor Storage Shed is a brilliantly designed, high-capacity storage solution that solves the common problem of outdoor clutter with style and ingenuity. Its standout Glidetop feature is not a gimmick; it fundamentally improves the usability of the shed, making it effortless to access every corner of the spacious interior. The durable, low-maintenance resin construction and ultra-sturdy reinforced floor provide confidence that it will protect your expensive equipment for many years to come.

The only significant consideration is the mandatory requirement for a solid, level foundation—a task you must be prepared to undertake for a successful build. We strongly recommend assembling it with a partner to ensure a smooth, frustration-free experience. If you have the space for its footprint and are ready for the minimal site prep, this shed offers an unparalleled combination of capacity, access, and durability. It’s an investment that pays dividends in reclaimed garage space and a more organized outdoor life. For anyone looking to store bikes, lawnmowers, or other bulky gear, we can’t recommend it highly enough. You can check the latest price and see if it’s the right fit for your backyard today.