Patios in Lyndhurst, shade, algae and slip

Stripping it out. Old paving, the bedding under it and any old concrete are broken out and excavated to a firm formation. In these gardens there is nearly always a layer of leaf mould and soft made ground under the slabs, and that has to go too. Roots, spoil and rubble leave by the load.

The sub base. MOT Type 1 whacked in thin lifts to full compaction and carried past the edge of the paving, with a geotextile separator underneath on soft ground. In a shaded garden the base never really dries out, so getting the compaction right the first time is the difference between a flat terrace and a rocking one.

Full bed and primer, not dabs. Slabs are bedded on a full wet mortar bed with a slurry primer on the back. A dabbed slab in a shaded garden holds standing water under it permanently, and permanently wet mortar has no strength left in it after a few frosts.

Grip is the first thing we choose for. Textured porcelain is the obvious answer on a north facing terrace: calibrated, non porous, and the grip is in the surface rather than in the stone being dry. Flamed granite is excellent too. Riven sandstone has natural texture but is porous and greens over. Limestone and travertine both hold moisture and we would steer you away from them here.

Falls, levels and the damp course. Paving falls away from the house and stops at least two courses below the DPC, and on the older properties here, where nearly four in ten homes predate 1919, there may be no proper damp course to work from at all. In that case the level comes off the floor inside. Approved Document C explains why.

Shifting water and leaves. A shaded terrace needs a slightly stronger fall than an open one, because the sun is not going to help. Water goes to a channel with a gully and an outfall, or to a soakaway where the ground will take the runoff, and any grating is chosen so leaf litter can be swept off it rather than packing into it.

Edges, steps and retaining. A haunched edging or kerb where the paving meets grass or a border, a retaining edge and coping where the ground is held back, and steps set out with equal risers. Under a canopy the step nosings are the part people slip on, so they get the grippiest finish on the job.

Jointing. A brush in resin compound worked in wet and tooled off. Open joints in a shaded garden fill with rotting leaf, and that is a seed bed for moss and algae. Mortar pointing still suits an old stone terrace. Then the usual repairs: lifted slabs, a sunk corner, rocking paving, cracked stone, efflorescence on new sandstone and staining under the drip line.

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

Getting to it. A Victorian villa with a long side path, a cottage on the High Street with no rear access, and a detached house with a gated drive 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 Lyndhurst, Emery Down, Bank and the lanes out towards Minstead, broadly SO43, with the New Forest National Park Authority as planning authority. 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.