Patios in Merley, and the flags that came with the house

What is under the old flags. On a Merley patio of this age, usually fifty millimetres of sand straight onto subsoil. It worked because a patio only carries people, and it has lasted four decades. What it cannot do is stay flat, because there is nothing spreading the load and nothing keeping the water out of the bedding.

Lifting and taking away. Old concrete flags are heavy and they are not worth much to anybody, so they come out and go into a grab lorry or a skip with the sand and any broken hardcore. Priced by the load rather than by the metre, and it leaves with us.

Digging to a proper depth. Once the old bedding is off we take the excavation down to firm ground, which is deeper than most people expect because the original build sat so shallow. That extra depth is where the difference between the two quotes usually is.

The sub base. Geotextile membrane over the formation, then MOT Type 1 in compacted layers rather than one deep lift. This is the part that makes the new terrace behave differently from the one it replaces, and it is invisible the day it is finished.

Full bed rather than sand. Slabs go on a full wet mortar bed, with a slurry primer painted onto the back of porcelain and dense stone. No voids, nothing for water to sit in, and nothing for a slab to rock on.

Porcelain, sandstone, limestone and granite. Porcelain takes almost no water, so it does not go chalky or hold moss the way old concrete does, and a textured face keeps its grip. Sandstone is warmer and easier to cut but porous. Limestone marks with iron. Granite is the hardest wearing. Calibrated slabs lay faster than hand cut stone.

Levels, edgings and steps. The new terrace falls away from the house and finishes two brick courses below the damp course, the level Approved Document C works to, which on these houses often means taking a course out rather than adding one. Border edgings are haunched in concrete, steps go off a footing with a coping front, and a retaining course gets a land drain behind it.

Drainage and jointing. Runoff into a channel drain and on to a gully or a soakaway, or a permeable build with open joints where the garden has nowhere obvious to send it. Joints brushed in with a two part compound and tooled off, which is what finally puts an end to the weeds.

Smaller repairs. Not every terrace in Merley needs replacing. We re-bed slabs that have lifted or sunk, cut out cracked ones, re-point joints that have washed out, and clean off the algae and efflorescence that make a sound patio look slippery and tired.

The slabs you choose are the easiest part to price, which is why a patio is never quoted by the square metre.

What comes up first. Old concrete flags, a concrete base under them, a raised bed or a buried rockery all have to be broken out and carried away. That is priced by the load.

Getting materials in. A wide side gate lets a barrow or micro digger through. A garden reached only through the garage means every bag of sub-base and every slab is carried by hand, and that adds days.

The base on sandy ground. Merley's sandy soil drains freely but can wash out and spread, so a patio needs a proper compacted sub-base of crushed stone and a full mortar bed, not dabs. On a small patio the groundwork can cost more than the paving.

Falls and the damp course. The patio has to fall away from the house and finish well below the damp proof course. Where the garden rises towards the back fence, that means steps, a retaining edge or a channel drain.

The stone. Porcelain needs a slurry primer and careful cutting; sandstone varies in thickness and takes longer to level.

When you compare, ask how deep the dig is, which sub-base and how thick, whether the slabs go on a full bed, where the water will go, and what jointing compound is used.

Boscombe, where our base is, lies 6.6 miles from Merley, and we cover the estates here, Bearwood, the Wimborne Road side and out towards Canford Magna, broadly BH21. The council for all of it is Bournemouth, Christchurch and Poole.

Bournemouth Roofing & Building Ltd is registered in England and Wales, company number 15471719, and Thomas Hannen owns it; he looks at the garden, the levels and the way in, and prices the patio himself. A verified customer rated the work 10 out of 10 on Checkatrade. The visit costs you nothing, nor does the written itemised quote. The flags at the back usually went down with the front, and a driveway in Merley tends to reach the end of its life at the same time. Before you book a visit in Merley, you can read our customers' Google reviews, word for word, on our reviews page.

Most repairs in Merley need no application at all. What decides whether a change to the outside of your house does is who the council is, whether a conservation area or a listing applies, and whether the place sits in a protected landscape.