Patios in Winterborne Kingston, built for winter ground

The trial pit. One hole tells you what a brochure cannot: how deep the topsoil goes, whether there is made ground under it, and how fast water leaves. On a plot near a winterbourne we want to know where the water sits, not just where it drains.

The dig and the muck away. Turf, topsoil, old concrete, roots and soft made ground get excavated out until the formation stops moving underfoot. On ground like this that is usually deeper than a standard build up, and the spoil leaves in a grab lorry or a skip rather than being spread over the garden.

The sub base. MOT type 1 in compacted layers with a geotextile between the subgrade and the stone. That membrane matters more here than almost anywhere: without it, a wet subgrade pumps up into the stone every winter, the sub base loses its grading and the paving settles.

Drainage first, paving second. An ACO channel across the low side and at any threshold, falls set to run into it, and a gully into a positive outfall. A soakaway is only worth building where the pit proves the ground takes water, and next to a winterbourne it often does not in winter.

Falls and the damp course. A consistent fall away from the house, and a finished surface at least two courses below the damp proof course. Where the threshold is low, a recessed channel across the door does the job that raising the paving must not.

Full bed, never dabs. A full wet mortar bed under every slab, with a slurry primer on the back of porcelain. Dabbed slabs leave voids, voids fill with water on ground like this, and the first hard frost lifts the flag.

Porcelain and stone. Calibrated porcelain absorbs almost nothing, comes in slip rated finishes and shrugs off a wet winter. Riven sandstone and limestone suit the older houses in the village, travertine less so on damp ground, and granite is the toughest of the natural options for steps and edges.

Edges, steps and retaining. Haunched edging or a kerb so the outer course cannot creep, a retaining edge with a coping where the ground is held back, and step treads on a full bed with an overhang so water drips clear of the riser.

Jointing and repairs. A resin grout brushed into damp joints, or pointing in mortar on riven stone. We also lift and relay sunk bays and rocking flags, cut out cracked ones, repoint washed out joints and deal with staining, efflorescence and a slippery green surface.

No rate per square metre, because the slabs are the part you choose and the smallest part of the price.

Getting to it. A cottage on the street with a barrow width path, a bungalow with a gate off the drive and a house with a paddock a lorry can turn in are three different jobs on the same area. Everything comes in and goes out through the garden, often through a side gate or the house. A patio you can barrow to directly is a different job from one where every slab is carried. The work at height rules still apply to the dig and the machinery.

What is coming out before anything goes down. An old concrete slab, a raised bed, tree roots or made ground all have to be dug out and taken away, and that is priced by the load rather than by the metre. The dig is where a patio quote is won or lost.

Falls, levels and the damp course. A patio has to fall away from the house and finish at least two courses below the damp proof course, and getting that right often means steps, a retaining edge or a drainage channel. Laying a new patio up against a wall at the wrong level is the single most expensive mistake on this kind of job.

Comparing quotes? Ask how deep the dig goes and what sub base is specified, whether the slabs are laid on a full wet bed or on dabs, what the falls are and where the water goes, whether edgings and steps are included, and what the jointing compound is. Two quotes for the same job are usually two different jobs.

The stream runs within about seventy metres of the village and the flood maps put parts of the settlement in flood zones two and three, with a high surface water risk band on top. You can check what applies to a particular address in a minute or two, and it is worth doing before any garden work.

The thing to understand about a winterbourne is that it is seasonal. The ground water rises through the autumn, the stream runs through the winter and spring, and by late summer it can be dry. Gardens along it behave the same way. Ground that takes a spade easily in August is heavy and saturated in January, and any base built without allowing for that is being tested in conditions nobody saw on the day.

So the build up here is deliberately conservative. A deeper dig, a geotextile under the sub base so a wet subgrade cannot work its way into the stone, compaction in thin layers, and drainage designed for the wet half of the year rather than the dry one. It costs more in the dig and the muck away than a summer job appears to need, and it is why the patios we lay here are still flat when the ones laid on a thin base are not.

We cover the village, Winterborne Whitechurch, Milborne St Andrew and the lanes along the valley, broadly DT11, under Dorset Council. You are dealing with Bournemouth Roofing & Building, the trading name of Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719, which you can look up in a minute. Thomas Hannen's business, and he is the one who comes out to price the job, not a salesman. A verified customer's 10 out of 10 on Checkatrade. The visit and the written quote are both free.