Brendan Teasdale

Recognising the type of issues and decay at an early stage is vital, salts, freeze/thaw, pollution, oxidisation of adjacent materials, wind erosion, structural defects and past inappropriate repair work are some of the likely causes of stone decay. I never copy and paste specifications and methods from one project to another because every situation is different. Instead, I carefully study the building to reveal the problems for which I prescribe the correct materials and methods from the information gathered. Analysis of materials are usually required to replicate historic lime coatings and finishes. Often buildings reveal their secrets if you look closely, evidence of historic materials and methods remain visible even after hundreds of years. I have also carried out extensive research in lime mortars which has enabled me to create a selection of mortars which play very different roles in preserving historic building fabric.

I have always had a passion for training future generations of masons and professionals alike. I have carried out many skills days as part of grant-aided funding for masonry projects.

I’ve also worked with organisations such as the National Heritage Training Group, local authorities and colleges.

In 2008 I joined the Orton Trust where I taught Banker Masonry for ten years before it closed in 2018.

I can work freelance to oversee/supervise masonry conservation works on site and actively train staff to ensure high levels of workmanship.

All treatments are based around minimum intervention and are only carried out after careful assessment of the defects and causes of decay. My specifications and methodology reflect the not only the causes of decay but, consider the building detailing and the environment. Materials should match the existing as close as possible but also may need to consider other environmental changes that did not exist at the time of the original construction.

My treatments mainly include the reversal of inappropriate repairs, mainly cement pointing and renders which have previously been applied to the detriment of the building fabric. Cement needs to be carefully removed so as not to damage the substrate, the repointing, harling, rendering and limewashing can then be applied to the substrate to protect the building as intended. Successful consolidation also relies on the packing out of wide joints with stone pinning’s and cuts down on mortar usage which in turn reduces shrinkage. Well consolidated masonry, containing no voids, will transport water from the core of the wall to the surface, removing harmful salts and keep the building dry.

Most historic buildings are in various states of decline, some by previous inappropriate repair schemes and others left to suffer the effects of nature through an antiquity of wear and ceased to function as was intended.

It is good practice to consider all options of repair. However, the choice should be the one with the least visual impact.  In the past, when stones have been replaced with new sawn ashlar, it has sometimes been carried out unnecessarily and can be unsightly if the building or structure shows excessive wear.

Other methods, including mortar repair or, the reconstruction of the core work, instead of new stone replacements, is very effective if done by experienced masons. Core work will also help to stabilise the surrounding stones and blend in much better with historic structures.

It may be reasonable however, to replace a carving of a new hoodmould or put back an element of architectural detailing with new stone. This type of repair helps to preserve craft skill and will also help to preserve the architecture of certain elements. The most often repeated phrase in conservation must be ‘conserve as found with minimum intervention'. If a decision has been taken to replace a stone, it should have been on the basis that there was no other possible option.