Fire Safety Regs - Timber Cladding

[john0wingnut]

Afternoon all

 

I have just had an inspection visit for my timber frame rear extension. It is a single storey 6x2 timber frame, 400 centres, 11mm OSB on the outside, breather membrane and is to be finished with vertical thermo pine, on batten / counter batten.

 

The BCO has advised I need to put intumescent cavity closers in at the top / bottom and around the windows and doors, which is not something I thought was required for ventilated cladding; I've just got mesh top and bottom. Windows / doors  have a cladding cheek to finish, so are closed already.

 

Can anyone on here enlighten me?

 

John