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Putting a shed directly on grass is the fastest way to throw your money away. It’s tempting to skip the prep, but after years of seeing sheds warped beyond repair or with floors you could put a foot through, we can tell you the lawn is one of the worst ‘foundations’.
Here’s exactly how to prep a grass site so your garden building lasts as long as possible.
Tips for Putting a Shed on Grass (That Actually Work)
While it’s possible to build a shed in the middle of your lawn, doing it incorrectly is a common cause of rot and warranty issues. For the structure to last 10+ years, there needs to be a proper base underneath the shed; one that’s flat, solid, and level. On wooden sheds, there must also be some airflow under the floor. Without it, moisture builds up, and the timber will deteriorate.
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Dig out the area
You don’t have to remove the entire lawn, especially if the grass is part of your garden’s landscape. Focus on the area where you plan to put your shed, and from there, remove any grass that might get in the way.
Outline the structure’s footprint using string or stakes so you don’t dig more than necessary. Mow the grass as low as possible, using a lawnmower, a sharp spade if it’s a small area or a turf cutter for larger spaces.
Pro tip: Slice the grass into strips before lifting, then lift or roll in sections. Break up any compacted soil to loosen stubborn roots. You want a firm, level surface to prevent moisture from getting trapped, especially if you have a wooden shed.
Choose and build your shed base
A clear, levelled ground is the golden rule for laying your shed’s foundation, whether it’s a metal shed or a plastic shed—no exceptions. Once the grass covering the spot is removed, you need to make the earth solid.
When it comes to the base, you’ve got a few options:
- A concrete slab is a poured mix of cement, aggregate, sand, and water that sets into a solid surface. The most durable base option but also the most labour-intensive to install.
- Paving slabs are pre-cast concrete or stone tiles laid flat in a compacted sand-and-gravel bed. They give a level, durable surface without the wet work of pouring concrete.
- You can also use bricks as a shed base. They lift the structure well off the ground. Make sure the bricks are level with each other and positioned to hold the floor bearers. If needed, adjust them with thin wood or similar material to even out the levels. The ground also needs to be firm. Otherwise, one brick may sink lower than the others over time. Bricks on top of grass with no underground reinforcement probably won’t last.
Check out our guide, ‘How to Build a Shed Base’, for step-by-step instructions and more tips!
Opt for a quick-fit base kit
If you want to avoid the mess of mixing concrete, a quick-fit base kit is your best bet. These are ready-to-use foundation systems that interlock to form a solid, level surface.
Our Ecobase Fastfit systems are a game-changer. They can either be placed on top of the grass (as long as this keeps it level) or buried in the lawn to sit flush with the ground surface. It does need a weed membrane to be fitted underneath if you want to prevent unwelcome growths coming through.
How it works: Fill each grid system with gravel, like pea gravel, that’s at least 10mm in diameter, and you have a solid base. This is a great alternative for a hassle-free, money-conscious foundation.
Round-up
Here’s a quick recap of what you can do when building your shed on grass: first, remove the grass to create a clear, level surface. Next, choose and build your shed base: concrete slabs and paving stones work for any type, including metal and plastic units. Finally, you can opt for a quicker alternative, which is a quick-fit base kit—bonus if it comes with a weed control membrane.
These techniques also apply to workshop sheds (which especially need a sturdy base to support equipment), log cabins, summer houses, and other garden buildings.
FAQ
Can I put a metal shed directly on grass?
It’s not recommended either. While the metal itself won’t rot like wood, the unstable surface will lead to tipping and misalignment over time. Plus, the interior may be subject to additional moisture and condensation, potentially leading to the rusting of tools and the corroding of panels over time. A metal shed properly anchored to a solid, well-drained base reduces the chances of rising moisture.
Does building on grass void my warranty?
In most cases, yes. Most manufacturers require the building to be constructed on a “suitable, level base.” If the timber fails because it was sat directly on damp grass, the warranty won’t cover the damage.
Up next on your reading list: Lawnmower Sheds – Guide to Buying a Mower Storage Shed
