Foundation Parging mixing formulas

[Jon Slattery]

I am in the process of chipping off the old parget coat

on my brick foundation and reparging it.

I've herd varying formulas for the mix. Everything from

1/2 Portland & 1/2 sand to 1pt. Portland (type n), 1/4 pt

lime & 3pts sand.

What is the best mix, is it measured by weight or volume

and which cement? (Type I, II, III masonry cement) or

(Type N, S or M Portland cement)