Apple cider vinegar can be diluted half-and-half with water for external application, and, when stronger measures are needed, it can be used full-strength.
1 Just the stone for a flagstone patio can cost $3 -$5 a square foot or more, depending on location and the type and quality of stone, or about $600 -$1,000 for an average patio up to 10'x20,' and $1,200 -$2,000 for a larger 20'x20' area.
Flagstone Patio Cost. Non-discounted retail pricing for: Flagstone pattern stone, 1 average thickness in sizes ranging between 12x12 to 24 x 36. Quantity includes typical waste overage, material for repair and local delivery.