A dome wire grate (Dutch: “boldraadrooster”) is a hemispherical mesh screen fitted over the opening of a drain pipe, gutter outlet, or roof drain. Its dome shape and wire mesh construction prevent leaves, debris, and small animals from entering and blocking the drainage system.
How It Works
The grate sits over or inside a drain opening with its convex surface facing upward. Water flows through the mesh openings while solid material is deflected:
- Large debris (leaves, twigs) slides off the curved surface
- Small particles are caught by the mesh, collecting on top where they can dry and blow away or be easily removed
- Water flow passes through unobstructed, maintaining drainage capacity
The dome shape is important because it provides a larger effective surface area than a flat grate, reducing the chance of complete blockage even when partially covered with debris.
Materials
- Galvanised steel wire — the most common, offering corrosion resistance at low cost
- Stainless steel — for aggressive environments or longer service life
- Copper — sometimes used on high-end or heritage buildings for aesthetics
- Plastic (PVC or polypropylene) — lightweight and corrosion-proof
Sizes
Dome wire grates are available to fit standard pipe diameters:
- 50 mm, 75 mm, 100 mm, and 125 mm for residential applications
- 150 mm and larger for commercial and industrial drainage
Application
Dome wire grates are used in:
- Flat roof drains to prevent blockages in internal downpipes
- Gutter outlets on pitched roofs
- Ground-level yard drains and area drains
- Balcony and terrace drainage points
Regular inspection and cleaning — at least twice a year and after storms — keeps the grate functioning properly and prevents water backup.
Related Terms
- Dome strainer
- Leaf guard
- Roof drain
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