ST. MARTIN'S CHURCH • BULMER

The tower was built in the 15th century and, apart from being raised in height in the 17th century, it has remained relatively untouched since.

 

The original construction of the tower was in an age when buildings were constructed from material close to hand. While there are sources of good building stone locally, these may have been reserved for abbeys and castles. A small village church like St. Martin’s was built from thin stone shale cleared from the fields or surplus stock from primitive quarries. A lot of the building stones are better suited to a drystone wall. However, some of the special features like carved windows and the buttresses used higher quality stone.

 

The local stone used for some of the more decorative features, like the windows, is geologically unusual in that it is part limestone (alkaline) and part sandstone (acid). This chemical imbalance weakens the stone when wet and over time it has become prone to splitting, erosion, and mis-shapening.

 

To maintain stability of the rubble stone walls the original builders built the walls very thick, selecting stones that pieced together reasonably well like an enormous jig saw. As they went along they would pack any gaps using mud, straw, and a little fired lime as a binder.

 

The scaffold was made of timber poles built into the wall as the tower was raised. The poles were later removed as the scaffold frame came down, and the holes in the walls plugged up. We know this was how the building was constructed because we found the ends of the round scaffolding poles left in the wall––fascinating glimpse into medieval technology.

 

The restoration work was essential because significant parts of the stone walls were cracked and falling to the ground. Large pieces of the mortar fill between the stones had eroded and birds were living in the gaps. In fact, the wall structure was at risk of localised collapse as the hollowing out was so extensive.

 

We discovered the core of the walls had been easily excavated by birds over the centuries because the mortar was nothing more than bound mud. While this may seem alarming, we also found that the mud simply packed out the thin stone blocks and individual pieces were otherwise locked together tightly like a dry stone wall. While some of the individual small stones were loose, these were easily removed and re-packed to bind the wall back together again.

 

In the 15th century, mud was a common material to use for wall stitching and when completed, walls then had a protective coating of lime wash or a lime render added. This smooth coating is a breathable waterproofing and helps water shed away from the face of the stonework.

 

Our repair works followed the authentic process of using a soft lime mortar for the consolidation and, due to the roughness of the stone, we applied mortar to the joints in the stonework. We decided to take the authenticity of the finishing approach further and added a thin lime wash which is referred to as a ‘shelter coating’. Over time, this thin layer will wear away from the face of the stone, having filled all the small holes and fissures in the stone.

 

The original stabilisation works involved raking out loose mud and sand from the wall ready for the new pointing. All of this loose material was collected by the stonemasons and was reused as the colour tint for the lime wash. It is the ideal colour to suit the local environment as it comes from the surrounding fields.

 

At the top of the western wall, we found a worn date stone marking the last major restoration with the year 1637 being barely legible. This stone has been replaced and now has two dates, 1637 and 2026––the date of our restoration.

 

The work on the tower was completed by Matthias Garn and Partner, a firm of master stonemasons based in York, under the supervision of our architect Andrew Wiles. The new stonework is Yorkshire sandstone sourced from Whitton Fell quarry near Leyburn.

 

The village is grateful to The National Lottery Heritage Fund who provided 80% of the funding to enable our Grade 1 Listed church to be restored. We also are thankful to other funders who helped with the balance of funding:

 

• Garfield Weston Foundation
• Yorkshire Historic Churches Trust
• Benefact Trust
• Sir John Priestman Charity Trust