Refractory, Fireclay or heatproof mortar??

[mickfitz]

Hello

I'm building an outdoor oven that's gonna take a lot of heat. I'll be using firebricks and now I need to source some high temperature mortar.

I'm having problems sourcing this kinda thing. I'm in Warrington Cheshire but prepared to travel as far as need to buy the stuff.

I'd appreciate if anyone knows of such stuff and a possible place to buy.

Thanks in advance

Mick