fireplace pointing

[Nanothermite]

i have a stone fireplace that needs pointing, radnorship stone which is quite flaky on the horizontal plane.

what type of pointing do i need as I understand the mortar needs to be softer than the stone.

what is the correct ratio for the mortar

I have read somehwhere on the net that 1 part white cement/1 part hydrated lime/6 parts sea sand. is this correct?

do i need lime, or is sea sand and cement ok?

is sea sand ok to use with lime?

will it withstand the heat from a woodburner?

I want to install a woodburner in about a month, is this too soon?

experienced advice appreciated.

 

[stuart45]

Lime mortar withstands the heat better. Use a 3/1 mix.

 

[Alastairreid]

Sea sand contains salts, which are apt, by attracting moisture, to cause permanent damp and efflorescence.