Sagging Gutter

What's happening?

Gutter is held by brackets screwed either to the fascia board or over the rafter feet, at centres the manufacturer specifies for the profile — typically around a metre, closer on long runs and near joints. A sag means either the brackets have failed or what they are screwed into has. Full of water, a gutter is far heavier than it looks, and each litre sitting in a dip adds load that pulls the next bracket. The sag then becomes self-reinforcing: water ponds at the low point, debris settles in the standing water, the extra weight deepens the dip. On a house where the fascia timber has gone soft, the screws simply pull out, which is why a sagging gutter is often the first visible sign of fascia rot.

What usually causes it?

• Brackets spaced too widely for the profile, or brackets missing after earlier work
• Fascia board rotten or soft, so bracket screws have no grip left
• Screws corroded or stripped in enlarged holes from repeated removal and refitting
• Ladder set against the gutter, deforming the profile and forcing brackets loose
• Weight of ponded water, debris and winter ice progressively pulling the run down — a gutter that ponds freezes solid, and the ice is heavy enough to distort the profile
• Plastic gutter deformed by long-term UV embrittlement so it no longer holds its shape between brackets
• Original run installed to no fall, so it ponded from day one and the load was always in one place

When should you call a fascia, soffit and guttering installer?

Call within weeks for a modest sag with sound fascia, and within days if the gutter has pulled away from the board, if it is over a doorway or path, or if the fascia is visibly soft. This is the point to get the fascia condition assessed properly rather than treating the gutter in isolation, because refixing a gutter to timber that has failed is wasted money. If several bays are dropping, expect the conversation to be about the fascia and the run together.

What will the fascia, soffit and guttering installer actually do?

• Take the gutter down over the affected length and inspect the fascia, rafter feet and roof edge behind it
• Assess the fascia timber properly — surface staining and structural rot are different findings — then repair or replace failed fascia, fitting new board where the timber will not hold a fixing
• Re-hang the gutter with brackets at the manufacturer's centres, closer near joints and on long runs
• Set a consistent fall to the outlet so the run drains rather than ponds
• Replace deformed or embrittled gutter sections rather than trying to straighten them
• Check that the underlay at the eaves discharges into the gutter over an eaves tray, not behind it