Soft Capping in Scotland: The context and potential of using plants to protect masonry
4.0
Flora and Fauna
4.1
Vegetation on Wall:
The turf of the cap is about 75mm thick, of fine grasses with a few wildflowers. The turf is generally set back from the edge and provides good stabilisation of the edge stones. The turf is apparently regularly, closely and carefully mown, with no damage to the stones apparent.
4.2
Surrounding Vegetation:
The broch is surrounded by lightly grazed rough moorland, with rocky outcrops. The immediate enclosed area is well-mown grass.
4.3
Species Survey.
Assessment by HL from photos Close mowing made identification of species difficult.
D=Dominant, A=Abundant, F=Frequent, O=Occasional, R=Rare, VR=Very Rare, *=Present Common Name
Latin Name
Broch Top
Broch Surroundings
Comment
Grasses: Crested Dogstail
Cynosurus cristatus
R
Perennial Rye Grass
Lolium perenne
D
*
*
Ruderals/Herbs: Creeping Buttercup
Ranunculus repens
Daisy
Belllis perennis
R
White Clover
Trifolium repens
O
Trees/Shrubs: None Mosses/Ferns: None 4.4
Fauna:
The cap and surroundings are possible grazed by rabbits.
5.0
Technique
5.1
Source of Technique:
Uncertain. Early uses by the Ministry of Works may have been influenced by SPAB guidance as well as vernacular techniques.
5.2
Season of Work:
Unknown
5.3
Preliminary Repairs to Structure:
Unknown. It is thought that the section of wall below was rebuilt as drystone walling to imitate the original, sometime prior to 1846.
5.4
Treatment of Existing Vegetation:
Assumed none
5.5
Soft Capping Technique:
The capping seems to have been a single layer of turf, laid flat onto a wallhead, where voids had been filled with small stones.
5.6
Vegetation: Source and Description
Assumed good quality local turf was selected.
5.7
Soil: Source and Description
It is uncertain whether a soil layer was applied, it seems likely that the wallhead was filled with stones and a layer of soil would follow the local vernacular, as described in the Roghadal Walls (CS5).
5.8
DPC:
None used
5.9
Defining Membrane:
None used
5.10
Fixing:
None apparent
5.11
Aftercare:
Not known
5.12
Maintenance:
The capping is closely and regularly mown.
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