Introduction
Pre-works roost structure
- Photos or annotated figures of roost structure
Pre-works roost description
- Roost material(s)
-
- Photos or annotated figures of roost
Proposed works
- Relevant annotated figures
Proposed mitigations
- Type of mitigation
- Mitigation
- Specific technical detail of measure
- An updated roost inspection took place in the lead up to the commencement of works, during which four brown long-eared bats including a juvenile were found, confirming indications of maternity roost usage from 2011. All works were carried out under an agreed Ecological Method Statement which included a pre-start briefing (‘toolbox talk’) for all site workers and ecological supervision by a suitably qualified ecologist. Ridge tile removals and the installation of fire doors were supervised by the Ecologist during periods of mild weather in October and November 2014, a time of year when bats are least sensitive to disturbance should they be encountered.
The fire doors compartmentalised the previously open roof void. To allow continued access throughout the roof void for the brown long-eared bat maternity/satellite roost, hatches measuring 400mm x 300mm with shutters fixed open by heat-activated fusible thermal links were added to the fire doors. The fusible thermal link is designed to break when temperatures exceed 68°C (above the temperatures that roof voids reach in natural conditions), closing the intumescent shutters and sealing the compartment to protect the property from the spread of fire in the roof void.
Pre-existing vent tiles were adapted to form two simple bat access points in each ridgeline within the separate fire compartments, and existing bat access points retained, to ensure the bats still have the possibility to escape after the shutters close.
Claydon House and the cottages at Greys Court both had hatches with intumescent shutters held open by temperature-activated links on the fire doors to protect bat access. Claydon House had the works proceed under ecological supervision in February 2014, after no bat sign was found during pre-works surveys; and the cottages at Greys Court had them proceed in a five-day period subject to ecological supervision in late spring 2014.
- Relevant annotated figures
- Roost location
- In Roof Void
- Aspect of roost
- Various
- Height of roost entrance (m)
- Various.
- Roost material(s)
-
- Bitumen Felt
- Timber Roof Frame
- Wooden Boarding
- Clay Tiles
- Other
- Nearest commuting feature
- Woodland
- Distance to nearest commuting feature (m)
- 20m.
- Photos or annotated figures of roost
Monitoring data
- Type of monitoring
- Roost Inspection
- Date and time
- 13th June 2017 12:00
- Evidence recorded
- 3 brown long-eared bats present at Bradenham Manor including a pregnant female. Fresh bat droppings present, including on fire walls and access points.
- Interventions made
- None.
- Type of monitoring
- Roost Inspection
- Date and time
- 14th September 2018 11:30
- Evidence recorded
- Minimum count of 22 brown long-eared bats in five separate areas across all roof void compartments. Evidence from inspections showing bat droppings on access hatches indicate that they will continue to use Bradenham Manor roof void.
- Interventions made
- None.
