Roofing Mold/Mildew

Submitted By
0 expert, 0 community

I saw a product in my local hardware store called 'Wet and Forget', that claimed to remove the mold/stain on shingled roofs. Is this product effective in doing that? The stain has been on the roof for a few years. Can you suggest an effective way to remove the mold/mildew stains/ Thanks