Corodrain Dry Fix Valley Troughs

Universal Dry Valley

Universal Dry Fix Valley Trough

Available in 3 height options as well as heavyweight and standard, the Universal Dry Fix Valley Trough is suitable for use in tile and slate pitched roofs.  The Universal Dry Fix Valley has options to suit High Profile Tiles, Low Profile or Plain Tiles and Slate Tiles. 


  • Mortar free Universal dry fix valley
  • 3 height options for different tile requirements
  • BBA Approved Cert. No. 89/2153
  • No wet trades needed, can be fitted in any weather
  • At least as durable as lead and similar in appearance
  • No clips needed, reducing time and hassle on site
  • Smooth surface inhibits the growth of moss & lichen and build-up of debris
  • Fire resistant to SAB to BS476 part 3 and Class 3 to BS476 part 7   

ideal for

  • Suitable for use on roofs with pitches from 17.5° to 49°
  • Can accommodate a maximum difference between two rafter pitches of 15°



Please contact our Technical Department who will be happy to advise on installation instructions.


  1. Valley boards should be fitted of sufficient width to provide support for the roofing battens, either: min. 12mm ply lay boards set between rafters, or 6mm continuous ply boards laid over the rafters.
  2. A single strip of roofing underlay should be laid up the centre of the valley.
  3. Counter battens the same depth as the roofing battens should be fitted onto the valley boards.
  4. The main roofing underlay should be laid over the counter batten. Roofing battens should be fitted with the ends firmly located onto the valley boards, positioned close to the counter batten, with care taken to avoid damaging the underlay.
  5. The fascia board should be cut to allow the GRP valley trough to pass through and discharge into the gutter without flattening out. The end of the GRP valley trough should be trimmed using a fine toothed hacksaw to the appropriate centre line of the gutter - which normally entails a ‘v’ shaped cut.
  6. The GRP valley trough should be fitted with care taken to ensure it is centrally located between the valley boards: the sides should be nailed to the counter battens at max: 500mm centres.
  7. Refer to lap requirements
 17.5°-22° 350mm 
 22.5°-29° 300mm 
 30°-39° 200mm 
 40°-49° 150mm


GRP lasts as long as lead, is tougher, cheaper, more resistant to accidental damage, and is less prone to theft or vandalism. Using preformed GRP valley troughs saves significant installation time over traditional methods. Roofers report elimination of many problems with valley troughs when changing from lead to CORODRAIN GRP. Coloured lead grey as standard (other colours available on request). 

Made with high quality un-filled polyester resin with glass fibre reinforcement for maximum strength. A tough bonded melinex film gives excellent weathering performance. Minimum life of 30 years. 

Manufactured to BS EN ISO 9001:2008 quality standard, our automated continuous pultrusion plant in Coventry. All available from stock for rapid delivery to site.

The inherent qualities of the materials make the valleys UV light and acid rain resistant, and the smooth surface finish inhibits the growth of moss, lichen and the build up of debris.


Width 280mm
Thickness 2mm
Standard Weight 3.6kg/m²
Length 3000mm
Colour Grey
Material GRP
Fire Rating SAB to BS476 Part 3  Class 3 to BS476 Part 7





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