All 10 shed bases in this collection, ranked on size for the money, guarantee and features. Use the finder to narrow them down.
Why it ranks here: low price per sq ft for a shed base, 10-year guarantee.
Why it ranks here: low price per sq ft for a shed base, 10-year guarantee.
Why it ranks here: mid-range price per sq ft, 10-year guarantee, 7% off the RRP.
Why it ranks here: 10-year guarantee, 7% off the RRP.
Why it ranks here: 10-year guarantee, 8% off the RRP.
Why it ranks here: 10-year guarantee.
Why it ranks here: 10-year guarantee, 11% off the RRP.
Why it ranks here: mid-range price per sq ft, 10-year guarantee.
Why it ranks here: higher price per sq ft than most, 10-year guarantee.
Why it ranks here: higher price per sq ft than most, 10-year guarantee.
How we score. The value score is our own sum from the listed specs and Shedstore's price. It is not a customer review and we have not tested the products. For a shed: 45% is price per square foot against other sheds, 25% is guarantee length, 20% is features (floor, windows, lock, double doors) and 10% is any saving off the RRP. Bases are scored on price per square foot and guarantee, storage boxes on price per litre, guarantee and lock. Give us your space and it becomes a match score that also rewards the products that make best use of it.
Adjustable shed bases give you a level platform for a shed on uneven ground without digging, mixing concrete or barrowing in tonnes of hardcore. Steel brackets fix to a timber frame and each one winds up or down until the frame sits dead level, then the shed goes on top.
Here you'll find all 10 QuickJACK kits sold by Shedstore: five for soft ground like grass and soil, five for hard surfaces like concrete, tarmac and old paving, from small 6x4 sheds up to 20x12 buildings. Want a gravel grid base instead? See our plastic shed bases.
It's a set of heavy duty, height-adjustable steel supports that hold a wooden frame level above the ground. That frame becomes the shed foundation, and your shed floor sits on it. Because every support sets its own height, it doesn't matter if the lawn has a dip in one corner or the patio falls away for drainage. You level the base, not the garden.
Every kit on this page is from the QuickJACK range, made in the UK and sold here under the ProBASE name. Some stockists sell the soft ground version as QuickJACK PRO, a heavy duty kit built for grass and soil. The QuickJACK adjustable shed base system comes in two versions.
Both lift the shed floor clear of the ground, so airflow underneath keeps the floor timbers dry and ventilated. That's the main thing that stops rot in a garden shed floor. The brackets also anchor the garden building, so it can't creep or lift in a strong wind.
The usual answer to a sloping or lumpy garden is to dig it level, lay hardcore and pour a concrete slab. That works, but it's a weekend of heavy work, it needs dry weather and it's there for good. An adjustable base skips nearly all of it.
There are limits. The adjustment tops out at 100mm on hard surfaces and 150mm on soft ground. If your garden drops more than that across the footprint, dig the high side down a little first. Very boggy ground also needs care, as the plates rely on firm earth below the turf.
Here's every kit Shedstore sells, matched by kit number. Find your shed in the compatible shed sizes column and pick the soft or hard surface version. Prices move every day and the grid above always shows the live price, so here they're grouped into bands.
| Kit | Surface | Shed sizes (ft) | In the box | Adjustment | Price band |
|---|---|---|---|---|---|
| Kit 1 | Hard | 4x3, 5x3, 5x4, 5x5, 6x3, 6x4, 6x5 | 4 corner brackets | 100mm | Under £125 |
| Kit 1 | Soft | 4x3, 5x3, 5x4, 5x5, 6x3, 6x4, 6x5 | 4 corner brackets, 4 x 6 inch bearing plates and screw piles | 150mm | Under £125 |
| Kit 2 | Hard | 6x6, 7x3 to 7x7, 8x3 to 8x6, 9x3, 9x4, 10x3 | 4 corner and 2 inline brackets | 100mm | £125 to £200 |
| Kit 2 | Soft | 6x6, 7x3 to 7x7, 8x3 to 8x6, 9x3, 9x4, 10x3 | 4 corner and 2 T brackets, 6 x 8 inch bearing plates and screw piles | 150mm | £125 to £200 |
| Kit 3 | Hard | 8x7, 8x8, 9x9, 10x4, 10x6, 10x7, 10x8, 10x10 | 4 corner and 5 inline brackets | 100mm | £200 to £300 |
| Kit 3 | Soft | 8x7, 8x8, 9x9, 10x4, 10x6, 10x7, 10x8, 10x10 | 4 corner and 4 T brackets, 1 cross plate, 9 x 8 inch bearing plates and screw piles | 150mm | £200 to £300 |
| Kit 4 | Hard | 9x11, 12x6, 12x8, 12x10, 12x12, 13x6 | 12 brackets | 100mm | £200 to £300 |
| Kit 4 | Soft | 9x11, 12x6, 12x8, 12x10, 12x12, 13x6 | 4 corner and 6 T brackets, 2 cross plates, 12 x 10 inch bearing plates and screw piles | 150mm | £300 to £400 |
| Kit 5 | Hard | 14x8, 14x10, 15x10, 16x8, 16x10, 20x10, 20x12 | 15 brackets | 100mm | £300 to £400 |
| Kit 5 | Soft | 14x8, 14x10, 15x10, 16x8, 16x10, 20x10, 20x12 | 4 corner and 8 T brackets, 3 cross plates, 15 x 12 inch bearing plates and screw piles | 150mm | Over £400 |
A few things the table shows. The soft surface kits cost a little more than the hard ones at every size, because they add the screw piles and bearing plates. The bigger kits also step up the plate size, from 6 inch on Kit 1 to 12 inch on Kit 5, so a heavier building has more steel spreading its load into the soil. Hard surface brackets are 6mm zinc plated steel, and the soft surface parts are 4mm zinc plated steel.
Go by what's under the shed, not what's nearby.
Not sure which shed size you're buying yet? Our plastic sheds with floors list every model by size, and the floor kit still wants a flat, level surface to sit on.
The QuickJACK adjustable shed base system needs a wooden frame that matches your shed's floor size, and it isn't in the box. Shedstore suggests timber at least 2 inches wide. Many fitters use 4x2 inch (100 x 50mm) pressure-treated timber, with joists across it where the inline or T brackets go. Once that's built, installation goes like this on soft ground.
On a hard surface it's the same idea, except the base plates screw to the concrete or paving, and you set the height by turning the adjusting nut, then tightening the locking nut. You'll need a drill, a spanner and fixings that suit your surface. Shedstore doesn't offer an installation service for QuickJACK kits, so this is a DIY job, but there's no heavy lifting beyond the timber itself.
Plastic and resin sheds are fussier about a level base than timber ones. Their wall panels clip into the floor, so if the base twists even slightly the doors won't line up and the panels can pop out of their channels. A wooden frame on QuickJACK brackets, decked with exterior plywood or boards, gives a flat, rigid platform that stays true. It also raises the shed above standing water, which helps on a wet lawn. If you're weighing up the two materials, our guide to plastic vs wooden sheds covers how each copes with damp ground.
Match the kit to the shed's outside footprint. A 6x4 shed fits Kit 1, and our 8x6 plastic sheds sit on Kit 2. For a big model from our large plastic sheds, Kit 3 covers up to 10x10. Bigger garden buildings such as workshops and summerhouses need Kit 4 or Kit 5.
Brackets aren't the only way to get a level base. Here's how they stack up against the other common choices in a UK garden.
For a flat lawn, a gravel grid is often the cheaper option. For a garden on a slope, an adjustable base usually wins on time, cost and effort.
The same QuickJACK brackets can support a small area of decking as well as a shed, and many people use them for a level deck on uneven ground. In England most sheds count as permitted development, as long as they meet the size and position rules in the Planning Portal guide to outbuildings. The base matters in one way. A deck or platform more than 30cm above the ground needs planning permission, as the Planning Portal decking guide explains. With up to 150mm of adjustment plus 100mm timber, a QuickJACK base usually stays under that, but measure from the lowest point of the ground on a steep slope. The government's permitted development technical guidance has the full detail. Wales, Scotland and Northern Ireland have their own rules.
No. Clear the area of plants and big stones, then the brackets do the levelling. If the ground drops more than 100mm on a hard surface or 150mm on soft ground across the shed's footprint, dig the high side down a little first.
No. Every QuickJACK kit needs a timber frame that matches your shed floor. Pressure-treated 4x2 timber is a common choice.
Yes, that's what the soft surface kits are for. The screw piles go through the turf into the soil and the bearing plates spread the weight so the frame doesn't sink.
Kit 3. It covers sheds from 8x7 up to 10x10, in both soft and hard surface versions.
The brackets fix to the timber and grip the ground, so they also anchor the building. For a light plastic shed in an exposed garden, fix the shed to the frame as well. Our shed security range covers locks and ground anchors.
The steel is zinc plated against rust and each kit carries a 10 year warranty. The timber is usually the first thing to need attention, so use pressure-treated wood to keep rot away.
