A valley gutter (Dutch “kielgoot” or “kilgoot”) is the gutter that lies in the internal angle where two roof slopes meet at an inward angle. This internal angle is called the “valley”. All the rainwater from the two adjoining roof slopes flows together into this gutter and is carried by the valley gutter to the eaves or a drainage point.
How it works
- The two roof slopes run towards each other and form a V-shaped internal angle
- The gutter lies in this angle, lined with zinc, lead or a plastic membrane (e.g. EPDM)
- Because the water of two slopes meets here, the gutter must be generously sized
Application
- Compound roofs — at extensions, dormers, L-shaped plans and towers where roof slopes intersect
- Gable and hip roofs that abut one another
Points to note
- The valley handles a lot of water; a gutter that is too narrow or too flat overflows in heavy rain
- Keep the gutter free of leaves and debris; a blockage in a valley quickly causes leaks in the structure below
- Provide enough fall and a sound waterproof layer under the roof covering along the valley
- Watch the junction of the tiles or slates with the gutter (valley rafter); a sloppy junction is prone to leaks
Related terms
- Valley
- Valley rafter
- Gutter
- Roof gutter
- Gable roof
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