In-plane GRP rooflights are not recommended for use in pitches below 4°, although some system manufacturers may allow this, subject to the limits of their system guarantee.  They can also be used as ‘wall lights’ in vertical cladding applications where required.  For roofs with a pitch below 4°, or for some specialised roof systems, kerb-mounted barrel vault rooflights are often the best option. We supply a GRP barrel vault rooflight system, Zenon Arc. Contact us for further information.