Upper floors
If appropriate, check that roofs and windows are bird-proof before nesting starts. Do not disturb bats. If you can, inspect lead flashings and mortar fillets at chimneys and roof wall abutments for signs of decay. Problems include holes or splits in the lead-work and cracked or missing mortar.
Top tip
Use a hand mirror to look behind downpipes as splits and cracks in old cast often occur here and can be missed.
Shopfront
Check that the top of shopfront is bird-proof before nesting starts. Make sure water is running freely off the shopfront to prevent water from entering the wall.