Manthorpe Alpha GRSV30-25 Roof Slate Vent & Integral Adaptor

(£11.94 Incl. VAT)
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Manthorpe Alpha GRSV30-25 Roof Slate Vent & Integral Adaptor

Manthorpe GRSV30-25 Alpha Slate Vents are an unobtrusive, economical roof ventilator providing 10,000mm/2 of air flow per unit.

The Manthorpe GRSV30-25 Alpha Slate Vent is manufactured as standard for 600 x 300 slates but can be easily trimmed to fit 500 x 250 slates using the pre marked cut lines.

It can be used for both high and low level roof ventilation requirements.

Alternatively it can also be used as an outlet terminal for extraction fans and soil pipe ventilation when used in conjunction with a Manthorpe GRPA Flexible Pipe (available separately).

The hood of the Manthorpe GRSV30-25 features a 4mm fly screen to prevent blockage from falling debris and entry of large insects into the roof space.



  • Airflow: 10,000mm/2
  • Size: 600mm x 300mm
  • Material: Polypropylene
  • Colour: Black
  • Minimum Roof Pitch: 15 degrees


  • Independently wind tunnel tested to the following standards:BS 6367- Deluge test 225mm/hour rainfall
  • Driving rain test down to a roof pitch of 15 degrees with an up roof wind speed of 13m/s & a rainfall rate of 200mm/hour


  • 10,000mm/2 of air flow per unit
  • Replaces one existing slate
  • Can be cut down on site to fit
  • Integral cowl with insect grill
  • Integral outlet feeds directly into roof space or can be used as a spigot for mechanical extraction by connecting a Manthorpe GRPA flexipipe (available separately)
  • Extensively independently wind tunnel tested
  • Minimum Roof Pitch: 15 degrees


The Manthorpe GRSV30/25 slate vent takes the place of one standard slate.

  • For 500mm x 250mm slates trim slate vent along marked lines.
  • Cut two adjacent slates directly below the slate vent.
  • Cut an inverted “T” in the felt and fold back
  • Fix slate vent into position using holes provided.
  • Secure front of slate using a copper disc rivet.
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