Major Church Restoration Project: Death Watch Beetle Damage

There is nothing more beautiful than a British church. Standing solid amid the countryside they look like they could stand for a Millennium. But there is one tiny wood-boring beetle that could bring the roof crashing down.

Church conservation and restoration projects are like rolling a couple of dice…you never really know what you are going to get! It is not until specialist tradesmen strip away the suspect fabric of a church or ancient building that they uncover the horrors of hundreds of years of silent creeping decay.

Edenham’s church of St Michael and All Angels, set amid Lincolnshire’s rolling and pleasant countryside some three miles north-west of Bourne, is a case in example. Project architects undoubtedly knew they had a major problem with the churches chancel and aisle roofs, what they didn’t know until the ‘lid’ was taken off is that 14 of the 18 massive oak beams holding up the chancel roof were virtually hanging in mid-air with very little support.

Roofers and carpenters contracted to do the sympathetic restoration work had seen it all before. Their arch-enemy, the death watch beetle, had been chewing their way through the damp and ancient oak beams that held up the roof, leaving what had once been the choice material to build Nelson’s battleships, little more than damp sawdust.

The mighty British oak trusses couldn’t resist attacks from an army of tiny 9mm long voracious wood-boring beetles. In some cases four to six foot lengths of once rock-hard oak have been completely chewed away leaving the infested wood feeling like a sponge.

The real damage is done by the larger 11mm long death watch larvae, their eggs deposited in the often already decaying wood by the adult beetles. When they hatch they begin tunnelling through the wood feeding on the natural cellulose it contains. They can’t digest what they are eating but use symbiotic intestinal microbes to process their food. Once fully grown they eat their way out of the wood leaving tell-tale exit holes.

Death watch beetles are associated with old buildings, especially churches. The tapping sound they make in the dead of night is thought to be the beetles banging against the wood to attract a mate. Their macabre name is linked with the watch or vigil kept over dead bodies as they lay overnight in a church, when the banging in the rafters is its loudest, waiting for burial the next day.

Edenham’s Anglo-Saxon church sits on what is thought to be the site of the Cistercian abbey of Vaudey founded in 1147. Edenham village gets a mention in the earlier Domesday Book of 1086, its wealth included five lord’s plough teams and 400 acres of woodland. From 1516 the land and villages have been owned by the de Eresby family of nearby Grimsthorpe Castle. Dukes and Earls have lived there in continuous succession since 1313.

Parts of the church date back to the 8th century, with several small parts remaining today. But it is during the 12th and 13 century’s that the church, which is mainly built out of ashlar, finely worked or cut limestone, begins to grow into what we now see. The four stage tower, with clasping buttresses and battlemented parapets, was built during the 16th century.

The church is a mason’s delight; shields, quatrefoil friezes, fleurons, cat’s heads, angels, ogee heads, dragons, dozens of fearsome yet beautifully carved gargoyles and animals decorating the building. And if you know where to look, try the corner of the parapet on the south porch, you might find something that makes you smile. It is thought to be a mason mooning, possibly the trademark of masons who worked in the Oakham area.

Large parts of the church roof, including the south and north aisles and the chancel, are currently (December 2014) protected by a vast tin roof sitting on a scaffold frame. The huge structure protects the exposed building while urgent repairs are made to the rotting roof areas. At the same time all the stonework is being closely checked as more weather damage is being found as the project unfolds.

Initially, a budget of £160,000, funded mainly by English Heritage and the Heritage Lottery Fund, has been agreed to cover the repair and conservation work but this is likely to increase as more damage is uncovered.

Carl Edwards, managing director of CEL, the Whittlesey-based historic building restoration company, and main contractor’s says: “It is a fascinating, if not sometime challenging project, because you just don’t know what you are going to find.

“The church is old, and has been added to over the centuries. Some of the work, especially the stone carving, is amazing, but some repairs made in more recent times fall well below the standards we would expect today. Obviously conservation was viewed with a different eye a 100-years ago.

“The main problem with the chancel roof is that previous repairs allowed soft wood to be used to replace rotten 300-year-old oak timbers, big steel straps have been added to the ridge timber to give extra strength, and hard-wearing cement has been liberally used to make repairs instead of mortar, which weathers at the same pace as the limestone, which the church is largely built out of.

“Carpenters are cutting out all the rotten wood, as much of the original material as possible is being retained, and we are using specially designed plates to strengthen what is left. The stonework frieze around the top of some of the walls are also in poor repair, some of it visibly loose, and our masons are carefully removing it, inspecting it for damage, inserting pins in the blocks and then bedding them in mortar.

“In fact, I was inspecting the frieze around the south porch and a whole highly carved corner stone came away in the masons hands. Much the same thing happened when we checked out the huge highly decorated cross that sits at the end of the chancel roof; it wasn’t anchored to the roof properly so we very carefully removed it, boxed it up for safe keeping and will put it back on when the new roof is finished.

“All the lead that has come off the church has been taken back to our factory and then melted down and recast so it can go back on the roof. The south aisle roof has had some repairs and we have used Douglas fir to re-board parts of it before covering with new code 7 lead,” explains Carl.

Because the span of the aisle roof is so large, the lead sheets have been laid on two levels, one slightly higher than the other. The lower section, gently sloping down to the gutter, is in position, the top leading edges held in place with strategically placed rows of copper nails. “This is to stop the sheets of lead creeping down the roof boards,” explains Carl. “The sheets of lead are wrapped over wooden formers at each joint, and then strips of lead are laid over the overlapped joints, which are held in place with solder. Once the lower level is completed the higher one is built the same way. A roof constructed like this with quality materials should last well over 100 years.”

So the next time you are driving past a church encased in scaffolding you might understand just want challenges the restoration and conservation teams face as they uncover history and find that tiny little beetles, and their larvae, have been feasting on the woodwork.

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Mel Russ