Ventilation Systems for H1

Trussed Roof Pitch >30°

For a Trussed Roof Pitch >30°, according to BS5250 (British Standards Management of moisture in buildings), a calculated airflow of 10,000mm² per linear metre at the eaves is required to manage moisture in the roof cavity. This is achieved by creating a calculated, unimpeded airflow system that will allow outside air into the roof cavity, past the insulation at the eaves complying with H1 and NZS4246:2016 and exiting through the apex of the roof, by means of negative pressure created by the applied ridge vent and the natural convection of the warm internal air. This manages moisture created/generated by means of construction moisture and occupancy behaviour. To manage and reduce the risk of dew point transference from roofing iron to underside of underlay caused by variance of temperature, creating separation and ventilation between the iron and underlay is recommended.

Trussed Roof pitch 15°-30°

For a Trussed Roof Pitch 15°-30°, according to BS5250 (British Standards Management of moisture in buildings), a calculated airflow of 10,000mm² per linear metre at the eaves is required to manage moisture in the roof cavity. This is achieved by creating a calculated, unimpeded airflow system that will allow outside air into the roof cavity, past the insulation at the eaves complying with H1 and NZS4246:2016 and out the other side via cross flow of air by means of negative pressure created by the. This manages moisture created/generated by means of construction moisture and occupancy behaviour. To manage and reduce the risk of dew point transference from roofing iron to underside of underlay caused by variance of temperature, creating separation and ventilation between the iron and underlay is recommended.

Trussed Roof Pitch <15°

For a Trussed Roof Pitch <15°, according to BS5250 (British Standards Management of moisture in buildings), a calculated airflow of 25,000mm² per linear metre at the eaves is required to manage moisture in the roof cavity. This is achieved by creating a calculated, unimpeded airflow system that will allow outside air into the roof cavity, past the insulation at the eaves complying with H1 and NZS4246:2016 and out the other side via cross flow of air by means of negative pressure created by the. This manages moisture created/generated by means of construction moisture and occupancy behaviour. To manage and reduce the risk of dew point transference from roofing iron to underside of underlay caused by variance of temperature, creating separation and ventilation between the iron and underlay is recommended.

Trussed Mono Pitch Roof >15°

For a Trussed Roof Pitch >15°, according to BS5250 (British Standards Management of moisture in buildings), a calculated airflow of 10,000mm² per linear metre at the eaves is required to manage moisture in the roof cavity. This is achieved by creating a calculated, unimpeded airflow system that will allow outside air into the roof cavity, past the insulation at the eaves complying with H1 and NZS4246:2016 and existing through the ridge cap of the roof at the high point, by means of negative pressure created by the applied ridge vent and the natural convection of the warm internal air. This manages moisture created/generated by means of construction moisture and occupancy behaviour. To manage and reduce the risk of dew point transference from roofing iron to underside of underlay caused by variance of temperature, creating separation and ventilation between the iron and underlay is recommended.

Trussed Mono Pitch Roof <15°

For a Trussed mono pitch <15°, according to BS5250 (British Standards Management of moisture in buildings), a calculated airflow of 25,000mm² per linear metre at the eaves is required to manage moisture in the roof cavity. This is achieved by creating a calculated, unimpeded airflow system that will allow outside air into the roof cavity, past the insulation at the eaves complying with H1 and NZS4246:2016 and existing through the ridge cap of the roof at the high point (Barge/apron), by means of negative pressure created by the applied ridge vent and the natural convection of the warm internal air. This manages moisture created/generated by means of construction moisture and occupancy behaviour. To manage and reduce the risk of dew point transference from roofing iron to underside of underlay caused by variance of temperature, creating separation and ventilation between the iron and underlay is recommended.

Pitched Skillion Roof

For a Pitched Skillion Roof , according to BS5250 (British Standards Management of moisture in buildings), a calculated airflow of 25,000mm² per linear metre at the eaves and a minimum of 5mm2 per linear meter at the high point (barge) is required to manage moisture in the roof cavity. This is achieved by creating a calculated, unimpeded airflow system that will allow outside air into the roof cavity, above the insulation throughout the roof cavity, complying with H1 and NZS4246:2016 and existing through the ridge cap of the roof at the high point (ridge), by means of negative pressure created by the applied ridge vent and the natural convection of the warm internal air. This manages moisture created/generated by means of construction moisture and occupancy behaviour. To ensure there are no blockage points through the roof cavity a 20mm vented batten is applied on top of purlins. To manage and reduce the risk of dew point transference from roofing iron to underside of underlay caused by variance of temperature, creating separation and ventilation between the iron and underlay is recommended.

Mono Pitch Skillion Roof

For a Mono Pitch Skillion Roof, according to BS5250 (British Standards Management of moisture in buildings), a calculated airflow of 25,000mm² per linear metre at the eaves and a minimum of 5mm2 per linear meter at the high point (barge) is required to manage moisture in the roof cavity. This is achieved by creating a calculated, unimpeded airflow system that will allow outside air into the roof cavity, past the insulation at the eaves complying with H1 and NZS4246:2016 and existing through the ridge cap of the roof at the high point (Barge/apron), by means of negative pressure created by the applied ridge vent and the natural convection of the warm internal air. This manages moisture created/generated by means of construction moisture and occupancy behaviour. To ensure there are no blockage points through the roof cavity a 20mm vented batten is applied on top of purlins. To manage and reduce the risk of dew point transference from roofing iron to underside of underlay caused by variance of temperature, creating separation and ventilation between the iron and underlay is recommended.