Issue 41 Spring web - Flipbook - Page 35
Tackling the growing roots of vegetation
Removal of vegetation is another common theme of ruin
conservation, particularly the challenge of removing and
discouraging invasive and woody species such as ivy, buddleia, and valerian. These can make their way onto ruined
structures via natural means but also by design. Planting
ivy was popular during the 19th century and was
frequently introduced and cultivated to enhance the
aesthetics of ruins. It is a particularly pernicious plant; the
roots can easily tunnel through a rubble core, ripping the
structure apart, and are almost impossible to eradicate
manually without completely dismantling the ruin.
Previously, the reliance has been on herbicides, but with
the ever-growing restrictions on their use, not to mention
the adverse effects they are known to have on the environment, it is necessary to find innovative approaches to
the issue of invasive vegetation. Currently, the most
sustainable solution is regular maintenance so vegetation
can be removed or suppressed before it becomes unmanageable. This approach, once established, also causes
minimum disruption to wildlife living in the area.
Preserving historic features is paramount
On each project, it is vital to identify historic features and
make every effort to preserve them. Even a single piece
of original ashlar, still in situ, offers insight into historic
building techniques and helps visually interpret historic
sites. At King John’s Castle, lower sections of the surviving
medieval chimney flue were in danger of collapse.
Cliveden Conservation’s stonemasons carefully recorded,
dismantled, and re-bedded each stone with the
incorporation of basalt bar supports. This allowed for the
historically significant feature to be saved without
compromising the aesthetics.
Above, Odiham Castle. The chimney flue after completion of works
to rebuild loose stones copy
When specifying mortars to consolidate what remains of
a ruin, aesthetic considerations must be balanced with
performance; the mortar must be robust enough to withstand a battering from the elements - something mortars
found in a rubble core would not have been required to
do – whilst retaining permeability, and the appearance of
the original mortars, taking into account visual differences
between building phases and day-breaks.
The effective use of soft capping
On various projects, we are now getting the opportunity
to not only install new turf soft capping but also inspect
and maintain established soft capping. Soft capping was
installed at Reading Abbey Ruins five years ago and
regular inspections have shown a good result. The wall
heads are weathering well, and the introduced droughtresistant sedum is thriving and appears to be suppressing
the growth of undesirable, woody species. It will be interesting to monitor progress over the coming years, but for
now it is offering an ecologically sound, low-maintenance
solution to protecting wall heads.
Opposite, MEWP access at Odiham Castle
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