Stourpaine repointing, and what holds the flints in

Pointing to the flint, not over it. A flint takes in no water at all, so everything the weather does to a flint wall happens in the mortar.

The fault to look for in Stourpaine is a wall pointed with the mortar run flat over the faces of the stones, which looks solid for a decade and then sheets away, taking flints with it. Done properly the mortar sits back at the face of the flint so each stone reads as a stone.

Raking a joint that has no straight lines in it. Stourpaine flint joints are deep, irregular and full of galleting, so there is nothing flat to work off and no depth gauge worth having. It is chisel work by hand, back to sound material and no further, in short lengths so the wall is never opened more than it can safely give. An angle grinder is useless here and worse on the brick beside it, where a disc cutter takes the arris off a soft handmade face for good.

The mix, and how much of it goes in. A Stourpaine flint wall swallows far more mortar than a brick one, and it wants a natural hydraulic lime with a sharp, well graded sand: strong enough to hold the stones, open enough to let the wall keep drying through the joint. We take a sample of sound original from a sheltered spot, match the sand for colour and grain, and dry a trial panel on your own wall first, because wet mortar reads darker than it finishes. The work goes in lifts, damped down and brushed back once the mix has taken up.

The brick banding and dressings. On Stourpaine walls the quoins, lacing courses and window surrounds are soft brick laid in lime, and hard cement there holds water inside the brick until a frost takes the face off. Where the cement has cracked away and is trapping water, it comes out and goes back breathable. Where it is sound and the brick behind it whole, we say leave it, because taking it out costs brick.

Spalled faces and stacks. A blown brick face will not recover, so the brick is cut out whole and a reclaimed match bedded in. A Stourpaine stack has no shelter and nothing warming it from within, so its joints go friable and the flaunching cracks long before anything at ground level. That is work at height, and the platform is its own line on the quote.

The area of the wall is the smallest part of the answer. How deep the joints go. A wall with shallow weathering rakes out quickly. One where the mortar has washed well back, or where the brick faces have spalled, takes far longer, and spalled bricks have to be cut out and replaced one by one.

Flint or brick. Flint is pointed stone by stone, with deep irregular joints and nothing flat to strike off. Brick is quicker. Where a wall mixes the two, each part is done its own way.

The mix. A cement mortar is harder than an old soft brick, so water leaves through the brick instead of the joint and frost takes the face off. Lime suits most pre-1919 walls, and matching the colour and texture takes a sample panel or two.

Getting up there. A garden wall needs no platform. A gable or stack needs a scaffold, and the work at height rules make it a line of its own.

Ask any other quote how the joints are raked, by hand or by disc, what the mix is and whether it has been matched, and whether the scaffold and licence are included.

On a brick wall the mortar keeps water out and the bricks hold each other up. On a flint wall the mortar does both, because a rounded flint has almost no bearing surface and nothing to bond to. So the mix here sits in a narrower window than anywhere else.

Too weak and the joint will not hold the stones. Too strong and the wall cannot dry through the mortar, so moisture works out through the brick banding and the soft dressings lose their faces. Lime, well graded sand and a gauge chosen for that wall satisfies both.

The second decision is the finish, and it separates a quote worth taking from one that is not. The instinct on a wall shedding flints is to smear mortar across the faces of the stones to make it feel solid again. It does, for about ten years, and then the whole skin lets go in sheets and the flints come with it. The joint has to come back flush with the widest part of each stone and no further, so every flint keeps its own shadow and water finds its way off the wall rather than into it.

So when you compare prices, ask where the mortar will finish against the face of the flints. Anyone who has pointed flint in this valley will have an answer ready. We put it in the quote and show it on the trial panel.

We are nineteen miles from Stourpaine, based in Boscombe, and we repoint across the village, Durweston, Bryanston, Blandford Forum and the DT11 villages either side of the Stour. Dorset Council is the planning authority for all of them.

Our company is Bournemouth Roofing & Building Ltd, number 15471719, registered in England and Wales. The owner is Thomas Hannen, and he scrapes the joints and prices the wall himself. A verified customer's Checkatrade review scored us 10 out of 10. The visit costs nothing and the quote, written and itemised, is free. Before you book a visit in Stourpaine, you can read our customers' Google reviews, word for word, on our reviews page.

Most repairs in Stourpaine 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.