Re: Concrete Mix
Posted by Jim Grady (70.109.175.184)
In Reply to: Re: Concrete Mix posted by Eugene
Taunton Publishing has an article on different mortar types on their web site. The article is from their "Fine Homebuilding" magazine. In that article, it describes Type N mortar as:
Type N: for exterior, above-grade walls
Type N is a medium compressive-strength (750 psi) mortar made of 1 part portland cement, 1 part lime and 6 parts sand. Type N is recommended for most exterior, above-grade walls exposed to severe weather, including chimneys.
On the Quikrete web site, they say to make Type N mortar, use 1 part Type N Masonry Cement and 3 parts Masonry Mortar. So, it sounds like their product is indeed 1 part portland cement and 1 part lime. So, if you use 2 parts of their Type N Masonry Cement and 4 parts concrete blend, you have what you need for the hearth slab. (remember that you will need to use 2 parts of the Type N cement to get the 1 part Portland cement and 1 part Lime.
I hope this helps.
Jim