Keyfix Non-Combustible Stainless Steel Weep Vent for Cavity Walls – Class A1 Fire Rated 

• The Keyfix Non-Combustible Stainless Steel Weep (NCW) range offers a Document B compliant, Class A1 fire-rated drainage solution for masonry walls. 
• Made from robust Grade 304 stainless steel, these weep vents are designed for 100–225mm masonry widths, providing long-lasting performance with resistance to electrolytic corrosion.
• Ideal for both standard and coastal environments, they seamlessly integrate with the Keyfix NCCT system or other stainless steel components.

Specifications

• Class A1 fire-rated and Document B compliant
• Made from 0.5mm Grade 304 or 316 stainless steel (125+ year lifespan)
• Fits masonry widths from 100–225mm
• Prevents electrolytic corrosion and integrates with stainless steel systems like Keyfix NCCT

Application & Installation Guidance

• Place a half-bed of mortar over the cavity tray before starting the brickwork.
• Install weep vents either directly on top of the Keyfix Non-Combustible Cavity Tray system or on the mortar bed.
• Ensure all weep vents remain free of mortar obstruction to allow clear drainage.
• Position weeps within 450mm of the tray stop ends, and then at 450mm centres along the cavity tray length.
• Make sure the perpendicular joint above the weep is fully filled with mortar to maintain structural integrity.

Corner Installation

• For corners, place weeps within 225mm of the stop end on the overlapping tray.
• Install two weep vents per corner unit to ensure sufficient drainage.
• Only stainless steel weep vents should be used with stainless steel trays to prevent bi-metallic/electrolytic corrosion and to maintain optimal system performance.