How to spot damaged flashing
Most flashing defects can be seen before water starts coming indoors. You just need to know what to look for – from the ground with binoculars, and from a ladder at the gutter.
- Sheet
- Damaged flashing
- Revision
- Sources
- 4 items
- Type
- advice article
From the ground
| What you see | What it may mean |
|---|---|
| dark streaks below a window sill | short nose or no drip fold |
| green or rust marks on the facade | water from copper, or rusting metal above |
| the gutter sags or “waves” | loose brackets, no expansion joints |
| water spills over the edge of the gutter in rain | blockage, downpipe too small, back-fall |
| wet plinth below a downpipe | blocked gully or no shoe |
| algae and moss on the facade below a parapet | parapet coping with no fall to the roof, or a short nose |
| verge flashing standing proud | loose fixings, risk of being torn off by wind |
From a ladder at the gutter
- corrosion: spot rust at cuts and scratches can be treated; widespread corrosion means the end of its life,
- white rust on new galvanised parts is often only cosmetic (the zinc has reacted with moisture in storage),
- cracked sealant at the chimney and walls,
- screw holes in surfaces where water flows,
- cracks in the joints of gutters and trims,
- metal swarf and rust spots on the paint after installation.
When to call a roofer straight away
- the sheet has rusted through,
- a trim or gutter has come loose and could fall,
- water is already getting into the structure,
- after a storm or hail there is visible deformation.
Regular checks
In spring and autumn: gutters, valleys, hoppers, downpipes, chimney and parapet flashings. See Maintaining flashings and gutters.
Technical sources
The sources this sheet draws on. We checked prices and values from standards on the date shown; for prices, whatever the source currently states always applies. Sources marked “in Slovak” or “in Czech” are only available in that language.
| Item | Source | Published by | Version / date | Checked |
|---|---|---|---|---|
| 01 | Ruukki warranty certificate – GreenCoat RWS Pro rainwater system 30 years; half the periods above 900 m above sea level (in Slovak) | Ruukki Slovakia s.r.o. | template 09/2026, for products sold after 1 September 2026 | 14 October 2026 |
| 02 | Lindab a.s. warranty certificate – conditions: min. gutter fall 5 mm/m, no contact with copper (in Slovak) | Lindab a.s. (Slovakia) | valid for products bought after 15 April 2019 | 14 October 2026 |
| 03 | RHEINZINK – Information material and processing (alloy to EN 988, electrolytic corrosion, effect of metals placed higher up) | RHEINZINK GmbH & Co. KG | RZ-INT-002-11-24 | 14 October 2026 |
| 04 | Installation guide – KJG half-round rainwater system 2025 (bracket fall, expansion joints, thermal expansion) (in Slovak) | KJG a.s. | 2025 | 14 October 2026 |
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- KlampiarskeVýrobky.sk
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