St Monica’s RC Church, Hoxton

Coping stone replacements in St Monica’s Hoxton

One of the unglamorous sides of masonry (most are!) but mandatory for the good of a building is to maintain or replace coping stones on gables and external walls.

Copings are there to let water drip away from the walls, so often a throat or groove is carved along the underside allowing the water to drip before running back onto the walls. Poorly maintained copings will lead to damp getting into your walls!

These particular ones had been rendered over with a sand and cement mix which as ever had peeled away from the stone and was now falling in dangerous sharp shards. The stones had also lifted from their mortar bed and were dangerously loose.

On the North gable the stones had long ago been replaced with cheap concrete slabs which had also lifted from their bed. Again, dangerous and aesthetically awful. In addition the lime mortar in the brickwork had failed, so we needed to call in bricklayers to repoint the bricks before we had a strong bed to build on.

IN all there were 4 different types of coping on the gables- one with 445mm wide with a chamfer on one side, one the same width with a cavetto, the springers were 480 wide and the slabs were 450 wide. We had to keep some but make it all consistent.

The springer had been replaced with a stone chamfered on one side. It was much thinner than the apex stone but was stuck on fast with epoxy and steel dowels. Taking it out would have damaged the brickwork even further, so the solution was to cop off both sides and extend outwards. The 2 new sides have been dowelled on using threaded M12 stainless bar and epoxy resin.

We left a functional and aesthetically pleasing coping which will last decades.