Not having enough of these protective substances can cause stones. Changes in the Acidity of the Urine. Changes in the acid balance of the urine can affect stone formation. 1  Uric acid and cystine stones mainly form in acidic urine.
1 For an average sized 1,500 square foot roof, that works out to a total PVC roofing cost of $6,000 to $18,000. 2  While certain types of PVC roofing material can be installed over the existing roof, the old roof may need to be removed and disposed of at an additional cost of $1.00 to $2.00 per square foot. While certain types of PVC roofing material can be installed over the existing roof, the old roof may need to be removed and disposed of at an additional cost of $1.00 to $2.00 per square foot.
These prices include installation but not tear-off of the old roof. 1  Built-up roofs cost anywhere from $200 to $700 per square. 2  Single-ply flat roofing costs about $150 to $400 per square.3  Spray polyurethane foam roofs cost about $300 to $500 per square. 4  Asphalt roll roofing usually costs about $150 to $400 per square. Spray polyurethane foam roofs cost about $300 to $500 per square. 2  Asphalt roll roofing usually costs about $150 to $400 per square. 3  Flat metal roofs usually cost $500 to $1,000 per square.