This 9mm thick rigid board is hollow, so lightweight and cost effective. Typically fitted to the underside of a soffit but this board is also used for internal cladding of walls, ceilings and sheds.

Features & Benefits

• Quick and easy fitting - push fits into 70mm hole
• Can be retro-fitted - use in new and existing soffits
• Strong and lightweight - made from durable polypropylene
• Flexible positioning - use for specific airflow needs
• Complies with BS5250 - 4mm wide slots

Did you know? When fitted every 200mm, this soffit vent provides recommended ventilation of 10,000mm2 per metre. For greater 25,000mm2 per metre airflow, fit staggered in two rows, with 86mm centres.

Technical Information

Fitting and Usage

Using the 70mm Circular Soffit Vents

1. First determine your airflow requirement. Flat roofs require 25,000mm2/m airflow along each soffit. Mono-pitch and dual-pitch roofs that aren’t used as living space and are of greater than 15°, require 10,000mm2/m airflow, all other mono and dual pitched roofs require 25,000mm2/m.
2. Measure spacing accurately and cut with care using a holesaw/cylinder saw of 69-70mm. Any larger than this and the vent may not hold securely.
3. Push the ventilator into place. You should feel resistance as it is inserted, and recognise a firm hold.
4. Ensure that you provide ventilation along the full length of each eaves to stimulate cross flow ventilation.

10,000mm2/m airflow can be achieved using one vent every 200mm, so allow 5 vents per metre.

25,000mm2/m airflow can be achieved by staggering vents every 86mm in two rows, so allow 12 vents per metre.