How to Tell If Your Gutters Need Cleaning
You do not need to get up on the roof to know whether your gutters need attention. Most of the tell-tale signs are visible from the ground during or just after rain.
What to look for
Water spilling over the front edge of the gutter during rain rather than running along it, tide marks or green staining down the brickwork below a gutter run, a gutter that visibly sags or pulls away from the fascia, and small plants or grass growing out of the gutter itself, which means enough soil and debris has built up to support root growth.
What you can safely check yourself
Standing well back from the house during heavy rain and watching where the water actually goes tells you most of what you need to know. If it is running off the edge anywhere along the run rather than into a downpipe, that section is blocked.