Grottos and churches

by Dearbhail Keating

Week 6 brought us away from Wales and back to the south taking in Somerset and Dorset. Two days were spent with Andy Ziminski, Fellow and director of Minerva Conservation and two days with Philip Hughes, Scholar and director of Philip Hughes Associates.

At the Church of St Peter and St Paul in Kilmersdon Andy showed us conservation work that is about to begin. The works will involve cleaning and conserving stonework, replacing the lead roof to the tower and repairs to the inside of the tower where a bell had fallen during a ringing exercise earlier in the year.

We carried out a trial area of stone cleaning around the doorway in the forth bay of the north aisle. The staining on the stone is due to air pollution and acid rain; this reacts with the stone creating calcium sulphate which forms a hard surface crust leading to subsequent blistering as salts expand behind.

To repair and conserve, initially the stone is brushed with water and phosphor bronze brushes, this can remove the sulphate salts which are soluble and with them, a degree of staining. But further cleaning is often required using a poultice.

In this case the poultice was a mix of paper pulp, water and ammonium carbonate. This is mixed together and pressed on to the area of stone requiring cleaning. Once the poultice is applied a chemical reaction takes place reverting the calcium sulphate to calcium carbonate which is the original make-up of the stone, thus stabilising it and slowing down further erosion

Applying the poultice

Applying the poultice

The doorway following the poulticing

The doorway following the poulticing

Following the poulticing we carried out mortar repairs to help support fragile edges of existing stonework. This method of cleaning and stabilisation will be used on several areas of the churches façade when works commence.

Later in the week, during our time with Philip Hughes, we were fortunate enough to visit St Giles House in Wimborne St Giles, Dorset. Built in the 17th century the house has been occupied by the Earl of Shaftsbury for many generations. Works are being carried out to a grotto in the grounds by Sally Strachey Historic Conservation. We spent the day on site getting involved in a very unique type of building conservation.

St Giles

St Giles

The fabulous shell grotto, dating from the early 18th century, is located to the south-east of the house. Grade II* listed, the grotto is an important example of its kind and has unfortunately fallen into disrepair. A grant from Natural England has allowed work to commence on the conservation of the grotto and the works are well underway.

Comprising of two main compartments and two side wings the grotto sits over a spring that feeds water to the ornamental lake. The building is of random rubble and flint construction with a slate roof. Internally the walls and ceiling are adorned with shells, flint, coral and fossils fixed to the walls, and the lath and plaster ceiling. Timber branches encased with shells were also suspended decoratively from the walls and ceilings.

Inside the grotto

Inside the grotto

The condition of the grotto when works began was quite bad indeed. A huge amount of work was carried out to save as much of the existing fabric as possible. All shells, coral etc. that had fallen were carefully removed and stored. Photographic evidence of the grotto before it fell into disrepair is available and the various options for reinstatement of the internal finish were debated.

The roof covering of the grotto had been removed; there are a number of roof structures that have built up over the life of the building through previous repairs. It was possible to view the condition of the ceilings from both above and below. There were problems with decay of timber laths and this was resulting in the plaster and shells falling from the ceilings. Some of the walls were studded out and decay had set in here, again resulting in loss of historic fabric. The timber branches covered in shells were also in need of attention.

Guided by the site team, we removed damaged laths and a wire was put in its place. This wire was fixed to the timber rafters on either side of the lath and secured with screws and washers. The wire ran along the line of the old lath and was a few millimetres above the plaster work. Following installation of the wire a water based epoxy resin was applied along the full length of the removed lath and built up into a peak along the line of the wire encasing it fully.

Scholar Charlie applying the epoxy resin

Scholar Charlie applying the epoxy resin

This method ensured the plaster work would have the best chance of remaining in situ, limiting the risk of it falling. Discussion is ongoing as to how repairs to the studded walls and decorative shell covered branches are to be carried out – we certainly did not have all the answers!

Thank you to all at Minerva Stone and Philip Hughes Associates for being such fantastic hosts, allowing us get our hands dirty and tutoring us in the world of stone and shells!


Glorious Mud!

By Alex Gibbons

I thought I’d take the opportunity to write about my favourite thing…mud! Last week SPAB ran the first ‘Glorious Mud’ courses in Slawston, Leics. The East Midlands has a rich cultural heritage of building with earth, which unfortunately goes relatively unnoticed compared with other clay-rich subsoil regions such as the South West and East Anglia. One reason for this, suggested by Anthony Goode who hosted the event, could be that the residents of the East Midlands continue to proudly refer to their earth building tradition as ‘mud’. Some might say that this is a less appealing name than ‘cob’ or ‘clay lump’, but I think it reflects the beautiful simplicity of the material and technique perfectly. The aim of the week was to get people interested, excited and educated in the mud building tradition of the East Midlands in the hope of bringing sexy back to mud. And I think we did a pretty good job!

After a couple of days setting up with Anthony, we were ahead of the game when the course delegates arrived on the Wednesday. There were about 25 of us in total, including local self builders, architects, conservation officers, Scholars, Fellows and a good group from the SPAB HQ in London.

We opened the bidding with tea (the only way to start any day of mud building) and several very interesting lectures on building with earth regionally and internationally by Jason Mordan and Stafford Holmes, as well as an introduction in the mud building tradition of technique of the East Midlands by Anthony.

After another quick cup of tea, it was time for course delegates to get their hands dirty! Guided by time-served mudman Derek, myself and Anthony, we began to make repairs to the bee damaged wall at Slawston. The wall had been a victim of masonry bees who had made their home in it – an all too common sight in earth buildings across the world. Mud has a great ability to store heat overnight in its thermal mass and is very easy to burrow in to, making it a perfect place for the bees to make their home.

P1110545Although the wall looks in a pretty sad state of repair, it is built so wide that really the bee damage is only superficial. Given enough time the bees will eventually burrow far enough to cause structural damage but with good maintenance this is unlikely to happen. Everyone got stuck in, mixing by foot and applying by hand. Mud building is a very labour intensive process but working together makes it great fun as well!


Course delegates also had the opportunity to make mud bricks and blocks, as well as a small rammed earth wall. Local school visits were run along side the main course, where participants had the chance to get their hands dirty and take their knowledge of making mud pies to the next level!


In the evening we were joined by building archaeologist, David Smith who gave an extremely interesting presentation on local mud buildings, rafterless thatch and much more.

The following day the weather was looking a little threatening so we ‘made hay while the sun shone’ and began by finishing the repair of the wall and wrapping up the practical element of the ‘Glorious Mud’ course.

Glorious Mud_8

When the rain started coming down again, we retreated inside for more lectures (and tea!), this time from architect Chris Granger, who had built a community centre in Bolivia with his wife, architect Scholar Chloe, using adobe blocks last year. After this, we handed over to Earth Building UK. I gave a presentation on modern buildings using earth as the main structural element and Dr. Paul Jaquin spoke about rammed earth buildings and the structural performance of earth. Earth Building UK is a not-for-profit organisation that fosters the conservation, understanding and development of building with earth in the UK.


After this it was back to architect Stafford Holmes, who gave presentation on a project he has lead in Pakistan, using lime to stabilise earth blocks in flood zones, so people can re-house themselves relatively cheaply in buildings that won’t wash away when the next floods come.

All in all, an extremely enjoyable and informative week, and I hope the first of many more to come! I think it really gave everyone a respect for the physical work that’s involved in building with earth, and how much easier they are to repair than to re-build.

I’d like to say a massive thank you to Anthony Goode for inspiring and arranging the course, to everyone at SPAB for organising, to all the speakers and to Derek for the practical sessions. May the East Midland mud buildings enjoy a resurgence of interest and sympathetic repair!

If you would like to find out more about building with earth, please visit


Cottage Conservation

by Conor Meehan

On Thursday the group re-joined Jo Hibbert to visit a nearby cottage where she and her husband Ed, a joiner, were working alongside the enthusiastic home owners. All parties rolled up their sleeves to muck in; Tyrone showed the Scholars how to “boss” and “dress” some lead for the house drainage valleys. It wasn’t long before Ross and Hannah were up on the roof installing the shaped lead under Tyrone’s watchful eye. Richard and Conor helped Ed erect his crafted green oak framework for the newly designed porch. Mortises, tenons and dowels were integral to the framework design, not a nail or screw in sight.

The homeowners were conservation enthusiasts and were experienced in the use of local materials – so much so, that both the Scholars and Fellow were soon mixing mortar from lime, locally sourced clay and straw reaped from the field next door, and throwing it up on the exposed interior stonework. Spending the day working on a small project where everyone involved could call upon recent teachings and contribute was really rewarding.

Pole Chapel in Colyton Church The week finished with a visit to the Pole Chapel in Colyton Church where Jo Hibbert and Torquil McNeilage, 1992 Fellow, discussed the damage associated with major moisture infiltration to the 16th century chapel and the sculptured memorial monuments.

Everyone thoroughly enjoyed their week in Devon and Somerset, the hands-on experience of different conservation disciplines was invaluable. The group had the chance to learn from master craftspeople, including Fellow leadworker and patient tutor, Tyrone. The West Country sunshine and homemade cider made it all the sweeter.


Thatching in the West Country

by Conor Meehan

During week 7 the four Scholars were joined by lead-worker Fellow, Tyrone Oakley for the week’s adventure. The group were guided by architect Jo Hibbert (2002 SPAB Scholar), the director at Levitate West Architecture and Design.

The first site visit of the week was to St. Thomas the Apostle Church in Exeter where Jo showed the group the affect of water infiltration on the building, as well as structural cracking and wide scale stone damage.

After securing emergency funding the structure was temporarily safeguarded and applications for further funding were made. 2009 Scholar Meriel O’Dowd, a Heritage at Risk surveyor for English Heritage, was also onsite to explain the allocation of emergency funds for buildings at risk.

Tuesday began with a visit to the Walronds, a Grade I Listed Cullompton townhouse. 2010 SPAB Scholar and architect, Andy Faulkner along with head architect, Marcus Chantry of Benjamin & Beauchamp Architects, were onsite to show us around the magnificent building.

Dating from 1605, the Walronds is now nearing the end of a large conservation project. The project has ensured that the house will continue to be the hub of the community and that it will generate long term funding options by providing space for events. The building was particularly interesting due to the diversity of the work being undertaken, such as plasterwork consolidation and repair, timber repairs, plastering, slate roofing, service installation and stone conservation.

New Picture (1)The day finished with off with a visual survey of St. Andrews Church in the same town, with Jo showing the group the various issues that she thought needed immediate conservation and repair.

On Wednesday, the group ventured to Somerset to meet Tom Dunbar, 1999 Fellow and master thatcher, who along with Nigel Bunce (also a master thatcher) was thatching two buildings in sunny Somerset. After a quick run through the thatching technique, the cocky Scholars were handed a wooden “legget” (a tool that hits the ends of the reeds and pushes them into position) and urged to have a go. Needless to say, thatchers complete a 4 year apprenticeship for a good reason! Attempting thatching in both water reed and wheat was a humbling and utterly worthwhile experience.

New Picture (3)