Bats in the dormer

This Lake District property had damage from water ingress below this dormer window, and a new window and flashing were made to resolve the problem. Once the scaffold was erected to install the window we were able to see the condition of the roof finish which was pretty poor and unsightly. The front gable of this dormer is an active maternity roost for Soprano Pipistrelle bats.  It seems likely the complications of obtaining a license and planning work around the bats meant that this roof was patched repeatedly rather than properly repaired.  

On stripping back the roof coverings we were surprised to find that the timber structure was generally in good condition – a couple of isolated areas of rot were repaired and the roof timbers were tied back to the main rafters and then it was ready for a new roof finish.

The roof and cheeks of the dormer were recovered in lead with a new ventilated space which wasn’t in the original construction, but we now know is essential for preventing condensation within the roof build up. The leadwork and shiny copper clips were a vast improvement on the sad looking finishes we’d removed, even as work progressed.

The front gable was carefully detailed to include a gap suitable for the bats to get in and out.  There is also a new lead covered ‘poop shoot’ to ensure that the cavity remains clear, battens to close off the roof space and all the materials were selected to ensure they would not harm or entangle any bats.

The finished lead looks crisp and new but also in keeping with the house. The lead capping piece finishes the top of the gable nicely and provides essential ventilation behind the lead for both the roof and the sides of the dormer. Finally, insulation made from compressed woodfibre was added into the roof, walls and coom space below the dormer from inside and the dormer finished internally with a vapour permeable lime plaster.

There was a lot to be considered and executed in a small area, all of which had to be completed within a short timescale to meet the Natural England license requirements. We are very pleased with the finished dormer and so are the specialist contractors who carried out the work with a lot of thought and careful detailing.