Product Data Sheet Show all documents

Cromar® Narrow Valley Trough

Trough for roofing system

GRP valley troughs offer a durable, cost effective alternative to lead and zinc valleys. They are easier to install, can be used on tile and slate roofs, and are long-lasting. They will create a weatherproof seal between roofs or terraced houses, or where a new roof needs to join an existing one.  

  • Convincing simulation of traditional lead.
  • Light and easy to transport, handle and install.
  • Virtually maintenance-free.
  • Dry fixing.
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Product Data Sheet Show all documents

Usage

  • For use with concrete/clay tiles or slate roofing as well as profiled GRP or metal roofs.

Advantages

  • Convincing simulation of traditional lead.
  • Light and easy to transport, handle and install.
  • Virtually maintenance-free.
  • Dry fixing.

Packaging

Boxed

Colour

Grey

Product Details

Product Information

Shelf Life

Physical plastic items have not had their shelf life determined due to longevity

Storage Conditions

The product must be stored properly in undamaged packaging, in dry conditions at temperatures between +5 °C and +30 °C.

Application

Application steps

APPLICATION

  • Valley troughs are fitted onto the valley boards and should be firmly fixed from the eaves closure section upwards, using suitable large headed roofing nails on either side of the trough and through the top flat section of the water bar, at a minimum of 500 mm centres.  All overlaps of troughs should be at least 150 mm when measured in the vertical. Care should be taken to ensure that the central raised section is not distorted in any way and that it is positioned central to the valley.
  • If the valley trough finishes at a ridge section with a corresponding valley, the top closure pieces can be used.  These closure sections overlap the valley troughs and underlap the slates / tiles that form over this point. The longitudinal battens of each valley should meet and be mitred so that the top of the top closure can be fixed with a suitable roofing nail to stop any movement. The top closure then overlaps both valley troughs by 150 mm and forms a neat, tidy, waterproof seal.

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