Please permit me to share my experience with worthy readers for mutual benefit. An Islamabad-based company applied bituminous based waterproofing product on the roofs of two houses and repaired a water tank at a cost of Rs 185,000. Roof waterproofing of both houses failed within a few months and water from the repaired tank deposits black bituminous particles on the water filter. The heat absorbing black bituminous roof waterproofing product has made houses an oven during the summer.

Perhaps concerned experts could suggest some long-lasting heat reflecting effective roof waterproofing system and safer material for water tank lining.

M. AKRAM NIAZI,

Rawalpindi, September 13.