Sometimes things start to happen with the curtain wall or glass which the occupant observes and knows shouldn’t be happening, and we get a call. Normally these investigations require an initial visit and preliminary report which we do for a fixed fee, and some instances will require further evaluation which we suggest as appropriate. Many of these relate to glass, particularly the phenomenon of spontaneous breakage in fully tempered glass, colour variation, surface distortion, etc. Other issues concern structural adequacy, humidity, glass or cladding panels disengaging, and many other topics. Recent reports have included an office where 14 floor to ceiling glass panels arranged as office and conference walls exploded simultaneously (fortunately no one was there), and a barrel-vault skylight with significant structural problems.