They should be above grade, below grade or filled with mortar.
The decision of whether type s or n mortar mix is better is determined by the application. N type mortar is used for above grade applications which see harsh weather while S type is used below grade like in ground application.
33 Mpa...for 43 grade cement
Very similar to regular block, but with a good grade of (usually white) mortar. Ask at a local flooring store what mortar they'd recomend.
grade 3
S contains 2 parts portland cement, 1 part hydrated lime and 9 parts sand, and yields maximum flexural strength to fight wind, soil pressure or earthquakes. Type N is a medium compressive-strength 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. Type S mortar is recommended for AT grade or below grade exterior applications. Type N is recommended for above grade apps.
10mm. 3/8"
grade 3 is a highier grade but 2 is lower, n
i was on a grade 3 with my employer I have now been put on grade 4 I do not know why
yes ! because grade 3 and primary 3 is the same!
3 grade
3/16 to 1/4".