Manthorpe Felt Lap Ventilator

The Manthorpe Felt Lap Vent is a refurbishment product designed to increase the amount of ventilation into existing roof spaces. Usually fitted retrospectively to properties with additional loft insulation recently installed, however the Felt Lap Vent will help to combat the problem of condensation build up in any roof space with a lapped felt/membrane construction. The product has been designed as a remedial solution to help overcome the build-up of condensation in the roof space, however like all products that open the felt lap to provide ventilation it does not meet the code of practice BS 5534:2014+A2:2018 6.2.1.1. The specifier or user should be aware that the opening of felt laps on the roof may adversely affect the driving rain resistance of the slates, tiles or shingles, as well as increase the wind uplift forces acting on them.