Sand/Cement Mix ?

[Red Devil]

I am about to build a brick fireplace behind a Cast Iron Fire insert. The fire is for decorative purposes only, and I would like to know what mixture of Sand/cement to use as mortar for the bricks.

Thanks for any advice

Con.

[The Natural Philosopher]

4:1

[Rick Dipper]

I am using 6:1 for mine.

Rick