St. Michael’s Spire and Tower: A Landmark to Keep

What was the problem?

The church mission, its community service and heritage value were all under threat due to structural deterioration in the spire and tower. These were first identified in our 2008 Quinquennial report and the building was subsequently made safe with temporary safety strapping – not the most attractive solution! The 2013 Quinquennial report and an additional bosun’s chair survey revealed further deterioration, marking the repairs as urgent. A survey in the spring of 2014 showed a greater degree of damage to the internal ironwork than anticipated and pointed to the need for a long-term solution….

After much surveying, meeting and discussing the project aims were defined:
  • To restore the damaged stonework on the spire and tower to the original 19th century appearance, using local Bath stone, local skilled workers and incorporating modern techniques including stainless steel supports within the stone and cathodic protection of remaining ironwork to prevent further corrosion.
  • To repair and restore the large stained-glass window (Jesse window) sitting within the tower.
  • To improve access within the tower for future maintenance and to repair the floodlighting scheme, which is currently not operational.For those of you keen to know the details….read on….otherwise skip to the pictures!
    The details….

    Detrimental weathering of the Bath stone mainly in the balustrade and pinnacles had led to moisture ingress. As a result the iron cramps used in the original construction had corroded causing expansion and spalling of the stone and thereby severely undermining the integrity of the whole tower structure. This process of degradation has been hastened by the presence of pigeon guano attacking the stone. In certain places the whole spire had lifted so much it was possible to see right through to the other side!

    Despite significantly increased costs to the project, a cathodic protection scheme was identified as the best way to ensure the longevity of the repairs and avoid a similar situation occurring in another 20+ years. The scheme selected is, we believe, the most cost effective – protecting the metal work that is most vulnerable to corrosion and most integral to maintaining a safe structure for the long term.
    In addition, the stained glass window (or Jesse window) that sits within the tower was identified as in being need of urgent repair. Much of it required re-leading and parts of the actual glass were cracked or discoloured. At the very top a hole had developed that not only spoiled the visual effect of the window but in a high wind allowed rain in! We felt it was prudent to take advantage of the presence of scaffolding to carry out these repairs as part of the same project, particularly as they had been identified as requiring completion within the next 3-4 years in the last Quinquennial report. Fortunately, the Heritage Lottery Fund and National Churches Trust agreed with us and allowed us to include the window in our funding applications.

    When the project parameters were finally agreed and tenders for the work obtained, the total cost of the project was just under £400,000. Not an enormous sum but certainly quite formidable for a relatively small Anglican church! A variety of fundraising efforts went on over two and a half years and we are indebted to everyone who contributed, however large or small the sum. It was clear that grant funding would be required however and we were blessed to receive sizeable grants from the Heritage Lottery Fund and National Churches Trust.

    Then one day in February 2015 our specially designed scaffolding began to take shape….

    Project Diary
    February – March:
    • The scaffolding was erected over a period of approximately two weeks – a fairly enormous undertaking!
    • During the planning stages we employed a specialist scaffolding design firm to ensure we would have the least possible impact on the pavement and road while not putting extra pressure on already vulnerable parts of the building.
    • Although the hoarding encroaches onto the pavement somewhat it was necessary to prevent us becoming the holiest climbing frame in Bath!
    • Once they had proper access the masons from Sally Strachey Historic Conservation could begin sampling the mortars and selecting new stone to ensure a ‘best match’ with the original materials.
    April:
    • Our previous surveys told us the pinnacles on the tower were the most damaged and vulnerable pieces of stone, particularly the south-west side as this suffers most from driving wind and rain!
    • More sampling of mortars and stone took place though difficulty arose over the sourcing of slate dust! Apparently other dusts could make suitable replacements however…this is certainly a learning process for most of us here!
    • Work began on this worst affected area by dismantling it gradually to assess how much stone would need re-carving and how much could be saved. We also needed to remove as much of the old iron work as possible as it is the corrosion of this that caused the stone to expand and crack. Unfortunately some parts were found to be in much worse condition than previously thought.
    • This month also saw the central part of the Jesse window removed – in only a matter of a couple of hours! The contracted firm, John Baker Glass, then took all the pieces back to their workshop to carry out the repair work there.
    May:
    • Dismantling of the pinnacles and crosses continued.
    • Dr David Farrell of Rowan Technologies arrived to begin work on the cathodic protection scheme. This is a means of protecting the remaining ironwork from further corrosion by bonding in a metallic ribbon through which a low voltage current is continually passed. More commonly used on naval ships it has proved an excellent long-term solution for maintaining the repair work into the future.
    • Investigations began to determine the best way to reinstall the floodlighting scheme whilst still ensuring we comply with previous planning requirements. There was much ferreting around to discover how the wires make their way from the roof all the way down into the crypt where the supply is located!
    June/July:
    • The real masonry work is now well underway. The various mortars sourced and approved – different parts of the building requiring slightly different mixes and shades.
    • Large blocks of ‘new’ stone began to arrive and had to be hoisted up one by one to the appropriate level. Once there the carving could commence! Luckily we had saved quite a lot of fallen/loose masonry which can be utilised in rebuilding the damaged areas
    • James Preston of Sally Strachey Historic Conservation was suspended by ropes to carry out work to the very top of the spire where the scaffold could not reach!

    • The cathodic protection scheme is complete and we await initial testing to see if it works…
    • Our beautiful window returned looking brighter and better than ever. Although not an unusual example of early 20th century church glass the window is dedicated to Ellen Taunton Little, a great benefactor of St. Michael’s who helped to revive the church and parish over 100 years ago.
    August:
    • Although our masons had kept the stone work on schedule there were delays with installing the new access decks and we were concerned this would delay striking the scaffold – with possible budget implications!
    • It began to feel like we may be falling at the last hurdle as it was discovered the wrong light fittings had been installed for the floodlighting AND two of the pinnacles were identified as having ‘sway’. This meant that although parts had been rebuilt and re-pointed etc. the entire pinnacle structure was moving several centimetres. And the pigeons were still present…

    • On a more positive note the cathodic protection scheme was now complete, passed its final test and was up and running. This will require little maintenance over the years and should ensure any structural ironwork that could not be replaced due to its position will not corrode any further.