What render for a builders opening

[raychmike]

Hi all
Firstly I have removed a back boiler and fire and intend to fit a new gas fire, the builders opening is 100mm to large to accommodate the closure plate. I intend to render the insides of the opening but fear that 50mm of render on each wall is to thick. I have thought of dot n dabbing the sides and then rendering over the boards so that they dont become exposed to heat. What render mix would you use for a job like this i was going to use a lime render @ 1/2/9 cement/ hydrated lime/ sand and mesh out the opening and throat it to suit. Would that be suitable for the opening or do you think boarding it out then rendering over that would be the best option ?

Ps before anyone goes into corgi mode don't panic as I am ACS qualified and working for a corgi plumber but unfortunately rendering walls aint his thing.
Thanks in advance
Mike

 

[oilman]

............... the builders opening is 100mm to large to accommodate the closure plate.

Was this a scene in the films seen by the Home Secretary's husband?

 

[swbjackson]

Why not just reduce the width of the opening at the front?

 

[keego]

Cut some concrete commons in half along their length & build up the sides with them.

 

[tryitandsee]

Was this a scene in the films seen by the Home Secretary's husband?

I don't know which is worse, watching those films or being a member of a DIYnot.com forum.