Mortar repairs and repointing in Beacon Hill

Reading the wall before mixing anything. Roughly one home in nine here is old enough to be solid wall, and the other eight are cavity. On a solid wall the only route water has out is the joint, so the mortar must stay softer and more permeable than the brick, which means an NHL lime or lime putty mix matched to the original sand. On a cavity wall the outer skin is a cement and sand mortar and the match is about the sand, the gauge and the colour. Getting that the wrong way round turns a tidy repair into a wall with spalled faces, so we establish which you have before quoting.

Nineteen sixties to eighties outer skins. Over four in ten homes here date from between 1945 and 1982, and the mortar of that period fails gently. It erodes at the arris, water stands in the open joint, and frost lifts flakes off the brick faces beside it. Joints come out to roughly twice their width, perpends by hand, and the angle grinder stays in the van. We damp the joints down before filling, then brush them back once the mortar has taken up.

Newer walls, and why they fail early when they do. Close to a third of the housing here went up between 1983 and 2008, which is young for repointing. When one of those walls is already open it is nearly always a local cause rather than age: a gutter running over onto the same strip of brick for years, a patio raised above the damp proof course, or joints struck too dry the day they were built. We deal with the cause at the same time.

Spalled brick faces. A blown face gets cut out and the brick turned or replaced against a sample held on the wall. Filling the hollow with mortar leaves a patch that never matches and falls out inside a couple of winters. Frost damage collects under sills, beside downpipes and in the first courses above the damp proof course.

Chimneys, and everything else at height. A stack has weather on all four sides and nothing warming it from inside, so its joints go friable years ahead of the walls below, and open joints up there come out as penetrating damp on a bedroom ceiling. That is work at height and wants a proper platform, priced as its own line. A bungalow or single storey extension will often come off a tower instead.

No rate per square metre: the area tells you almost nothing until somebody has looked at what the joints are actually like.

Getting to it. A detached house with a gable taking the weather off the open ground, a semi where two owners share an elevation and a bungalow with a stack on the ridge are three different set ups. A chimney or a gable wants a scaffold, and how long the platform stands matters as much as how big it is. Access under the work at height rules is a priced line, not absorbed into a rate.

The joints decide it, not the wall. How deep the joints have to come back, and whether the faces have already spalled, sets the hours far more than the area does. Hand raking is slow, but a disc widens the joint and takes the arris off.

Matching is the part that shows. Too strong a mix holds water against a soft brick and the face blows off in the first hard frost. Lime is the right answer on most pre-1919 walls here.

Comparing quotes? Ask how deep the joints are raked and by hand or disc, what the mix is and whether it was matched, how many spalled bricks are being replaced, and whether the scaffold is in the price.

Beacon Hill is one of the few places we work where the mortar is purely a technical decision. There is no conservation area covering it and nothing on the list, so nobody has to approve a colour, a sand or a joint profile before a wall is touched. A few miles away, on a listed cottage or inside a conservation area boundary, the mix and the strike are part of what is protected and the specification has to be agreed first. Here it does not, and that takes weeks out of the front of a job.

What it does not do is make the choice free. The wall still decides the mix, and the wall does not care about planning: pick a mortar harder than the brick and the faces will spall whether or not anyone consented to it. The other thing worth weighing is your neighbours' half of the elevation, because on a semi the joint you strike is the one somebody else has to match one day. We write the mix and the profile into the quote so the decision gets made once, on purpose.

We cover Beacon Hill, Lytchett Minster, Upton, Corfe Mullen and across to Broadstone and Wareham, broadly BH16, 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.