The small town where I live gets below freezing in winter and above 100º F in summer. I need to know which mortar joint width and ratio is best for laying a brick patio myself. As far as I know, mortar joints will break into pieces because of thermal expansion and contraction. Using just fine sand as a joint filler does not seem workable because my neighbor's patio which used this method has weeds growing at the joints.
Which ratio would expand/contract less? A 1 part cement and 3 parts fine sand; or a 1 part cement and 6 parts fine sand ratio? (In the local construction store they only sell cement and fine sand bags; so I will have no opportunity to buy additives or lime to increase flexibility.)
I plan to lay the patio bricks directly on my sandy-earth rather than on a sand base.
Each brick is 2.5 inches in height and width.
So what are the recommended mortar joint width and ratio so the patio will last for decades and not break into pieces within a few years?
Or are there other approaches I should consider?
This is what I intend to build: