Patios in Winterborne Stickland, wet winter ground

Finding out what the ground does. A trial hole is worth more here than anywhere. It tells us how deep the topsoil goes, whether there is chalk, clay or made ground below it, and whether water is already sitting at that depth. Old concrete, roots and rubble come out with the dig and the spoil goes by the load.

The sub base. MOT Type 1 laid and whacked in thin lifts to full compaction and carried past the edge of the paving, with a geotextile separator between the stone and the subsoil. Ground that saturates in winter and shrinks in summer moves, and the separator is what stops fines being pumped up into the base.

Full mortar bed, never dabs. Every slab on a full wet bed with a slurry primer painted on the back. A dabbed slab over ground that floods seasonally has a void underneath that fills every winter, and that is the mechanism behind almost every rocking patio we are called out to.

What goes down. Porcelain is calibrated, takes up no water and does not stain, so it comes through a wet winter unchanged. Riven sandstone is warmer, porous and darkens. Limestone marks and suits the chalk village stonework. Granite is the hardest wearing. Travertine is for a dry sheltered corner rather than a garden that sits wet for months.

Levels and the damp course. Paving falls away from the house and finishes at least two courses below the DPC, and in a garden that gets wet in winter that clearance is worth taking in full rather than at the minimum. Approved Document C explains what happens when the damp course is bridged.

Drainage that works in February. This is the part that catches people. A soakaway tested in a dry spell can pass and then do nothing when the water table has come up to meet it. So the design here is normally a channel with a gully and an outfall that keeps working when the ground is already full, with a permeable build up over open graded stone where a hard outfall is not available.

Edges, steps and retaining. A haunched edging or kerb where paving meets grass or a border, a retaining edge with coping where a level is held back, and steps set out with equal risers. On a village plot that falls towards the stream line, a continuous retaining edge across the flow is something we avoid rather than something we build.

Jointing and repairs. A brush in resin compound worked wet and tooled off, or hand pointing in a suitable mortar on older stonework. Open joints let winter water straight into the bedding. Then the usual repairs: lifted slabs, a sunk bay, rocking paving, cracked stone, algae on the shaded side, efflorescence on new sandstone and silt staining after standing water.

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

Getting to it. A thatched cottage on the village street, a farmhouse with a yard you can back a lorry into, and a modern house on the edge of the village are three different jobs. 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.

We cover Winterborne Stickland, Winterborne Whitechurch, Turnworth and the villages down the Winterborne 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.