The Manthorpe White Felt Lap Ventilator improves airflow through felt laps in existing roof spaces, helping to reduce condensation build-up, particularly after additional loft insulation has been installed.

Easy to fit between felt laps, it features a tapered lead-in and three securing clips for reliable installation, even where the felt edge is degraded. Suitable for joist centres from 400mm to 600mm, it provides 3,000mm²/m airflow; additional ventilation measures may be required to meet overall roof ventilation requirements.

• Dimensions: 275 x 193.5 x 18.5mm; weight: 0.074kg
• For existing roof spaces with lapped felt or membrane
• Helps reduce condensation after loft insulation upgrades
• Fits joist centres from 400mm to 600mm
• Provides 3,000mm²/m airflow through felt laps
• Tapered lead-in makes fitting between felt laps easy
• Three felt clips secure the vent, even with degraded felt
• Not suitable as the sole source of roof ventilation