Most roofs can support loads of 20 lbs. per sq. ft. On average, solar panels add a mere 3 lbs. per sq. ft. of weight to the roof. If your roof is in good shape, then a properly installed Shinnova system will not impede the strength or lifespan of your roof. In-fact, a solar panel system might make your roof last longer by shielding it from weather and UV rays.