Total Sheds
Installation Guides · 6 min read
Step-by-step timber shed base installation: level the ground, lay a membrane, set the tanalised bearer frame and square it up — done in an afternoon.
No mixer required
A tanalised bearer frame lifts your floor off the ground, spreads the load and gives you a dead-level platform — fitted in an afternoon with hand tools.
The quickest way to shorten a shed's life is to sit its floor on damp ground. The single best thing you can do for a timber floor is lift it clear, so air moves underneath and dries it out after every wet spell.
That's exactly what a timber base does: a tanalised bearer frame the building's floor sits on, lifting it off the ground, spreading the weight and giving you a dead-level platform on ground that's nearly level. We've made them in our West Midlands workshop since 1995, from the same pressure-treated timber as the buildings. Here's how to fit one properly — and when you shouldn't. For the wider groundwork picture, start with our shed base guide.
The gap under the frame lets the floor dry from below — the single best thing you can do for a timber floor's lifespan.
The bearer frame takes the building's weight and spreads it across the whole footprint, so nothing sinks and nothing twists.
Turns nearly-level ground into a true, flat platform in an afternoon. No mixing, no curing, no waiting for the weather.
Re-plan the garden in five years and the base lifts and goes with the building. Concrete doesn't.
Cut from the same pressure-treated timber as our sheds, in the same workshop, and sized to each building's footprint.
Eight steps, hand tools only. On a reasonably level site one person fits a timber base comfortably in an afternoon — two make lighter work of the frame.
Mark the building's footprint plus working clearance on every side, then strip the turf slightly wider than the base itself. Turf left under a frame rots down unevenly and holds moisture exactly where you don't want it.
Work across the cleared patch with a straight edge and a spirit level. You're not after billiard-table perfection — the frame handles small variation — but the closer you get now, the less packing later.
Tip: Always dig high spots down rather than piling soil into low ones. Undisturbed ground stays put; loose fill settles and takes your corner with it.
Roll a weed membrane over the cleared ground, overlapping any joins by a good hand's width. It stops vegetation growing up into the airflow gap — that gap's one enemy.
Build the bearer frame to its instructions on the flattest hard ground you have — a patio or drive is ideal. A frame goes together truer on a firm, flat surface than on soil.
Set the frame on the membrane and check it with a spirit level on a straight edge in BOTH directions. Pack any low corner with treated timber offcuts or paving offcuts until the bubble sits centred each way.
Careful: Never pack on loose bricks sat straight on soil. They tilt and sink as the ground moves, and the floor follows them.
Measure corner to corner both ways. Equal diagonals mean the frame is square; if one run is longer, nudge the frame until they match. A square base makes the building above it go up straight.
In most gardens the building's own weight holds everything down. On exposed, windy sites, some fix the bearers to ground anchors or pads for extra security — a sensible half hour's work.
That's the groundwork done. The building's floor sits directly on the bearers — no waiting, no curing. The build can start the same day the base goes down.
Nine times out of ten, a wonky shed is a ground problem, not a base problem. Two habits matter most. First, dig, don't fill: soil you've just loosened will keep settling for months, so cut high ground down to meet low rather than building low ground up. Second, don't skip the membrane — the airflow gap under the bearers only earns its keep while it stays open, and one summer of nettles will close it. If you'd rather watch than read, our animated base preparation guide walks the whole sequence through.
Still weighing timber against slabs or concrete? The foundation options guide compares every method honestly. And if you're wondering what "tanalised" actually means, here's the plain-English explainer — the pressure treatment behind the 15-year anti-rot guarantee on our timber buildings. Our base kits are cut from the same stock, sized to each footprint — add one in the Build Studio or alongside any catalogue building in the shop.
Yes — it's cheap insurance. The airflow gap only works while it stays open, and a membrane stops grass and nettles growing up through the frame. It takes five minutes to lay; skip it and you'll be strimming under a shed.
On a lawn site, yes — but not on the turf itself. Strip the grass back slightly wider than the base first. Turf under a frame breaks down unevenly, holds moisture against the bearers and makes a true level impossible. Bare, firm, levelled soil with a membrane over it is the right surface.
Decades. Tanalised timber is pressure-treated right through, not just coated, so it resists rot for the long haul — ours is the same timber our buildings are made from. There's no structural upkeep: just keep vegetation out and the airflow gap clear.
Usually not — once the building is on top, its own weight does the job. On exposed sites, some fix the bearers to ground anchors or pads. If your garden funnels the wind, it's worth the extra half hour.
Yes. Any garden building that wants a flat, dry platform will sit happily on a bearer frame — the airflow and load-spreading work just the same. Check the frame matches the footprint and follow the manufacturer's fixing guidance.
Run down this list the day before delivery and the build itself becomes the easy part.
Every Total Sheds timber base is made in our workshop from the same tanalised timber as the shed it carries, sized to the exact footprint you configure. Add the sized base kit as you build yours.
Open the Build StudioReady to put it into practice? Every building is made in our West Midlands workshop with free mainland delivery.
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