Description:
SVMAJ – Rytons Slim Vent® Major (Cavity Vent/Weep)
General Details
Rytons Slim Vent® Major (SVMAJ) is a perpend unit for airflow and drainage, designed for wide cavity walls and a discreet, flush finish.
Features and Benefits:
- Extra long perpend cavity ventilator for use in timber frame and traditional build.
- Open faced to give maximum airflow and prevent clogging by paint and airborne debris.
- Huge airflow allows fitting at the maximum 1.2m centres in Scotland and approximately every third brick to NHBC Standards, giving a cost efficient advantage.
- Internal and external water baffles prevent water transfer and make the vent an effective weep hole for drainage.
- Clean lines maintain the aesthetic appearance of the building.
- May also be used for cross-cavity and underfloor ventilation.
Important: This is a plastic component and is not suitable for use in the following:
a) external walls of buildings over 11m high where people sleep, whether residential, institutional or hospitality; or
b) external wall surfaces within 1m of a boundary where the building is 11m high or less, in England.
For a compliant alternative, see Rytons A1® Fire-rated Slim Vent® Major with Flyscreen part of Rytons A1® Fire-rated Range.
Size:
304mm L x 66mm H x 10mm W (allows a 6mm venting gap).
CAD drawing available by email.
Free Area:
330mm² per unit.
Colours:
Clear.
Composition:
High impact polystyrene.
Installation:
Installation is fast and simple as work proceeds, with the Slim Vent® replacing the vertical mortar joint. If required, the Rytons Slim Vent® Major may be cut to length using a fine-tooth saw.
Vents should be installed approximately every third brick at the top and bottom of the cavity wall to provide ventilation and assist drying. Lower vents should be positioned below the DPC, or above the cavity tray where one is used. Where installed above and below horizontal fire stops, vents should be vertically staggered.
Handling Information:
- Box quantity: 25 number.
- Box size: 32cm W x 10.5cm H x 29cm D.
- Box weight: 2.5kg.
Reference Material:
- NHBC Standards 6.2, External timber framed walls.
Ventilation openings should be equivalent to open brick perpends every 1.2m (i.e. 650mm² free air every 1.2m). These openings can also provide drainage of the cavity.
- The Building (Scotland) Regulations – Domestic, 3.10.6, Masonry outer leaf. Where the outer leaf is a masonry construction, cavities should be vented to the outside air by installing ventilators with at least 300 mm² free opening area at 1.2 m maximum centres. Precipitation, i.e. rain, snow and sleet, can penetrate the outer leaf of an external wall and cavities are normally drained through weep holes. These weep holes can also provide the necessary venting.
- British Standards BS 5250
Refer to current guidance for cavity wall ventilation and moisture control.
NBS Specification:
Rytons is proud to be a family run business and British manufacturer since 1972
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