Our team Clean and Bright windows did an excellent job on skylights in Bedford street in Bath. Removing a dried cement from the glass. We clean windows and skylights every month for the regular customer, using our soft brushes and purified water. However we couldn’t clean the cement off the glass with just soft brushes and purified water. It wouldn’t come off, so I had to get up on the roof and do it by hand using special chemicals, applicator, squeegee and good scrim.