Fireproof sheathing and cladding

[JackOfNoTrades]

Hi all 

Can anyone help me bounce around ideas for a sheathing and cladding option for the boundary wall side of my timber frame kitchen extension? 

There will be a very small gap between our extension and the neighbour's, not enough to do maintenance, and I'm looking for a long-lasting, flame resistant option there. 

 

My initial thought was whether I could use a fibre cement board as the sheathing on that side and then fibre cement cladding over this, but adding the cladding and necessary battens feels like an unnecessary extra thickness to a wall in a side of the kitchen where every bit of space counts. I was wondering if there is a product that could act as both the sheathing and the cladding, or another option that provides fire-safety, weathertightness and longevity in the minimum possible thickness. 

 

So I guess my questions are:

- Does anyone know of a fibre cement board or similar material that could be used for both sheathing and as a final cladding surface?  

- If the above doesn't exist, does anyone have any recommendations for me as to the best cladding for that side of the extension that can never be accessed for maintenance except for a pole to scrape out any leaves?

 

Thanks so much for your help everyone! 

Jack

 

[Mr Punter]

You need the battens as you have to incorporate a drained and ventilated cavity.