Valley Gutters

A horizontal valley gutter is formed at the bottom of two opposing roof slopes.

Although generally horizontal in plane they should actually be designed with a fall as their purpose is to collect the rainwater discharging off the roof and carry it away to the rainwater disposal system.

Valley gutters are frequently lined with mineralised felt, asphalt, lead or glass reinforced plastic. Mineralised felt is generally the cheapest option but may prove a false economy as when a mineralised felt is used in this situation it would typically have a life-expectancy of around fifteen years, whereas a well-designed and installed lead lined valley gutter should provide good service for at least 80 years.

Regardless of what waterproof lining has been used, valley gutters are often the source of roof leaks as they are prone to becoming blocked by leaves, moss etc., and maintenance is often neglected as they can rarely be seen, either from the ground or any other vantage point.

If a valley gutter is blocked, rainwater may rise above the edges of the lining and into the roof, causing dampness, fungal decay and damage to wall and ceiling surfaces.

If you are concerned about the condition of a valley gutter, contact Woodward Chartered Surveyors in Herts, Middlesex and London to arrange for an inspection.

Kate Farrar MRICS is a Chartered Surveyor and Director of Woodward Chartered Surveyors.

Woodward Chartered Surveyors cover an area from East of Oxford, High Wycombe, Beaconsfield, Amersham, Berkhamsted, Watford, Rickmansworth and into London, Northwood, Uxbridge, Harrow, Ealing and Mayfair.