Chapter one
Gutters and downpipes beside two rivers
On low ground the roof's job does not end at the eaves, because the water it collects still has to go somewhere.
Isfield grew up beside a ford, on the flood-plain of the River Ouse where the River Uck joins it. Whatever the ground does in a wet winter, the roof has to deliver its rain somewhere, and on low, damp land the drainage at the bottom of a downpipe matters as much as the pitch above. We trace that water from the ridge to the ground. A common finding on older houses is a gutter that has sagged between brackets, so it holds a pool of water, silts up and overflows over the fascia, the board that carries the gutter at the eaves. The overspill soaks the timber and runs down the brickwork, and the cause looks like rising damp when it is really a roof problem.
At a glance
- A roof sheds water only as well as its gutters
- Gutters need a gentle fall towards the outlet
- Brackets sit no more than 900mm apart
1.1 What a sound gutter run looks like
Makers of plastic systems recommend a very gentle slope towards the outlet, with the brackets set close enough that the run cannot dip. Brett Martin gives the fall as 1mm in every 600mm, and FloPlast recommends about 1 in 350 for its MiniFlo range. We check both by eye and with a level. On a house where the fascias have gone soft, repairing the gutter alone will not last, so our gutters, soffits and fascias work covers the whole eaves line in one visit. We look at the base of each downpipe too. Where the pipe ends at a gully or soakaway, we note whether it is clear, and tell you if the problem sits with the drain rather than the roof, since a drainage engineer, not a roofer, is the right person for that.
1.2 Why the roof matters here too
Overflowing water also finds its way under the lowest course of tiles or slates, where it soaks the ends of the rafters and the felt. Rot there is invisible from the ground. A lifted tile at the eaves, a split felt or a missing eaves comb, the little strip that props the first course and keeps birds and wind out, all show on a close inspection. For the pitched coverings above those eaves, our roof repairs page shows how we decide between a patch and a larger job.
Gutter fixing facts for low-lying ground
- Fall to outlet
- About 1:600 to 1:350 by system
- Bracket spacing
- No more than 900mm apart (Brett Martin)
- Recommended fall, MiniFlo
- 1:350 (FloPlast)
- Typical roofline life
- 10 to 20 years for fascias and soffits (MyBuilder)
Source: Brett Martin; FloPlast MiniFlo guide; MyBuilder, fetched October 2026




